Android如何列表显示数据库内容_course

搞了一天了还是没能弄出来，只好求助大家了。我在Android里面有一个数据库表：表名 MYTABLE，只有一列，列名：BODY 现在我想从这个表里取出BODY下的所有数据，然后将数据显示到列表List

安卓 从数据库中取数据Cursor的使用_course

listview使用cursoradapter 读取数据库中的ID字段 int a = listViewRight.getFirstVisiblePosition(); Cursor cursor1 = adapterRight.getCursor(); Cursor cursor2 = adapterRight.getCursor(); Cursor cursor3 = adapterRight.getCursor(); cursor1.moveToPosition(a); cursor2.moveToPosition(a + 1); cursor3.moveToPosition(a + 2); int listId1 = Table.getID(cursor1); int listId2 = Table.getID(cursor2); int listId3 = Table.getID(cursor3); 发现取出的三个ID都相同 单独取就正常 想请教一下这里应如何修改？

Android 如何模糊查询数据库其中一列，并将对应结果显示在list中_course

已经建好一个数据库并且在data/data/packagename/下。 现在在学习绑定了按钮监听并且查询，但是模拟到按查询button时就程序自动退出 public void onClick(View v) { test = SQLiteDatabase.openOrCreateDatabase( "data/data/com.example.ediantong/test.db", null); String key = et.getText().toString(); String sql = "Select type from table22 where price="+"%"+key+"%"; Cursor c = test.rawQuery(sql,null); c.moveToFirst(); //SimpleCursorAdapter适配器 SimpleCursorAdapter test = new SimpleCursorAdapter(test.this, android.R.layout.simple_list_item_2, c, new String[] {"un", "an" }, new int[] { android.R.id.text1, android.R.id.text2 }); lv.setAdapter(test); } 我是照着网络上代码改的，数据库有android_matadata表，table22 也有_id 主键了。

android.database.Cursor错误！_course

``` public class DLXMainActivity extends AppCompatActivity { DatabaseHelper databaseHelper; MyAdapter adapter; private static Toolbar toolbar; public static EditText dlx_Input1,dlx_Input2; public static String datetime; public static TextView mTitle,mContent,mTime; ListView listView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.dlx_task3_dlxmain); findViews(); setSupportActionBar(toolbar); databaseHelper = new DatabaseHelper( this, databaseHelper.DATABASE_NAME, null, databaseHelper.DATABASE_VERSION); List<Map<String, Object>> list = new ArrayList<Map<String, Object>>(); Map<String, Object> map; databaseHelper = new DatabaseHelper(this,DatabaseHelper.DATABASE_NAME,null,1); for(int i=0;i<10;i++) { map = new HashMap<String, Object>(); String title = null,content = null,time = null; while(databaseHelper.Querytitle().moveToNext()){ title = databaseHelper.Querytitle().getString(databaseHelper.Querytitle().getColumnIndex("title")); content = databaseHelper.Querytitle().getString(databaseHelper.Querytitle().getColumnIndex("content")); time = databaseHelper.Querytitle().getString(databaseHelper.Querytitle().getColumnIndex("time")); } map.put("title",String.valueOf(title)); map.put("content", String.valueOf(content)); map.put("time",String.valueOf(time)); list.add(map); } adapter = new MyAdapter(this,list); listView.setAdapter(adapter); } ``` 完全新手！想把数据库里的内容放到页面上，错误Caused by: android.database.CursorIndexOutOfBoundsException: Index -1 requested, with a size of 8,求大家指点！！！！！

android studiod 从数据库读取数据失败_course

从数据库读取数据到listview，但是不知为什么，在没添加数据进数据库的时候，能进activity，但是一旦添加进去以后就开始报错了 DBhelper.java public class DBHelper extends SQLiteOpenHelper{ private final static String DATABASE_NAME = "demo.db"; private final static int DATABASE_VERSION = 1; private final static String TABLE_NAME = "request_list"; public final static String REQUEST_ID = "request_id"; public final static String REPORTER_NAME = "reporter_name"; public final static String S_DESCRIPTION = "s_description"; public final static String L_DESCRIPTION = "l_description"; public final static String DEPARTMENT = "department"; public final static String CATEGORY = "category"; public DBHelper(Context context) { super(context, DATABASE_NAME, null, DATABASE_VERSION); Log.e("Database operations", "Database created/opened"); } @Override public void onCreate(SQLiteDatabase db) { String sql = "CREATE TABLE " + TABLE_NAME + " (" + REQUEST_ID + " INTEGER primary key autoincrement, " + "" + REPORTER_NAME + " text, " + "" + S_DESCRIPTION + " text, " + "" + L_DESCRIPTION + " text, " + "" + DEPARTMENT + " text, " + "" + CATEGORY + " text);"; db.execSQL(sql); Log.e("Database operations", "Table created/opened"); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { String sql = "DROP TABLE IF EXISTS " + TABLE_NAME; db.execSQL(sql); onCreate(db); } public Cursor select() { SQLiteDatabase db = this.getReadableDatabase(); Cursor cursor = db .query(TABLE_NAME, null, null, null, null, null, null); return cursor; } public Cursor getInformation(SQLiteDatabase db) { Cursor cursor; String[] projection = {REPORTER_NAME,S_DESCRIPTION,L_DESCRIPTION,DEPARTMENT,CATEGORY}; cursor=db.query(TABLE_NAME,projection,null,null,null,null,null,null); return cursor; } //增加操作 public long insert(String s_description,String name,String department, String category,String l_description) { SQLiteDatabase db = this.getWritableDatabase(); /* ContentValues */ ContentValues cv = new ContentValues(); cv.put(S_DESCRIPTION, s_description); cv.put(L_DESCRIPTION,l_description); cv.put(REPORTER_NAME,name); cv.put(DEPARTMENT,department); cv.put(CATEGORY,category); long row = db.insert(TABLE_NAME, null, cv); return row; } //删除操作 public void delete(int id) { SQLiteDatabase db = this.getWritableDatabase(); String where = REQUEST_ID + " = ?"; String[] whereValue ={ Integer.toString(id) }; db.delete(TABLE_NAME, where, whereValue); } //修改操作 public void update(int id, String s_description,String name,String department, String category,String l_description) { SQLiteDatabase db = this.getWritableDatabase(); String where = REQUEST_ID + " = ?"; String[] whereValue = { Integer.toString(id) }; ContentValues cv = new ContentValues(); cv.put(S_DESCRIPTION, s_description); cv.put(L_DESCRIPTION,l_description); cv.put(REPORTER_NAME,name); cv.put(DEPARTMENT,department); cv.put(CATEGORY,category); db.update(TABLE_NAME, cv, where, whereValue); } } DataListActivity.java public class DataListActivity extends ActionBarActivity { ListView listView; SQLiteDatabase sqLiteDatabase; DBHelper dbHelper; Cursor cursor; ListDataAdapter listDataAdapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.data_list_layout); listView = (ListView) findViewById(R.id.list_view); listDataAdapter = new ListDataAdapter(getApplicationContext(),R.layout.reporter_my_request); listView.setAdapter(listDataAdapter); dbHelper = new DBHelper(getApplicationContext()); sqLiteDatabase = dbHelper.getReadableDatabase(); cursor = dbHelper.getInformation(sqLiteDatabase); if(cursor.moveToFirst()) { do { String name,title,department,category,description; name = cursor.getString(0); title= cursor.getString(1); department=cursor.getString(2); category=cursor.getString(3); description=cursor.getString(4); DataProvider dataProvider=new DataProvider(name,title,department,category,description); listDataAdapter.add(dataProvider); }while (cursor.moveToNext()); } dbHelper.close(); } } DataProvider.java public class DataProvider { private String name; private String title; private String department; private String category; private String description; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public String getDepartment() { return department; } public void setDepartment(String department) { this.department = department; } public String getCategory() { return category; } public void setCategory(String category) { this.category = category; } public String getDescription() { return description; } public void setDescription(String description) { this.description = description; } public DataProvider(String name,String title,String department,String category,String description){ this.name= name; this.title = title; this.department= department; this.category= category; this.description = description; } } ListDataAdapter.java public class ListDataAdapter extends ArrayAdapter { List list = new ArrayList(); public ListDataAdapter(Context context, int resource) { super(context, resource); } static class LayoutHandler{ TextView NAME,TITLE,DEPARTMENT,CATEGORY,DESCRIPTION; } @Override public void add(Object object) { super.add(object); list.add(object); } @Override public int getCount() { return list.size(); } @Override public Object getItem(int position) { return list.get(position); } @Override public View getView(int position, View convertView, ViewGroup parent) { View row = convertView; LayoutHandler layoutHandler; if(row == null){ LayoutInflater layoutInflater = (LayoutInflater)this.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE); row = layoutInflater.inflate(R.layout.reporter_my_request,parent,false); layoutHandler = new LayoutHandler(); layoutHandler.NAME = (TextView)row.findViewById(R.id.text_name); layoutHandler.TITLE = (TextView)row.findViewById(R.id.text_title); layoutHandler.DEPARTMENT = (TextView)row.findViewById(R.id.text_department); layoutHandler.CATEGORY = (TextView)row.findViewById(R.id.text_category); row.setTag(layoutHandler); } else { layoutHandler = (LayoutHandler)row.getTag(); } DataProvider dataProvider = (DataProvider)this.getItem(position); layoutHandler.NAME.setText(dataProvider.getName()); layoutHandler.TITLE.setText(dataProvider.getTitle()); layoutHandler.DEPARTMENT.setText(dataProvider.getDepartment()); layoutHandler.CATEGORY.setText(dataProvider.getCategory()); layoutHandler.DESCRIPTION.setText(dataProvider.getDescription()); return row; } }

Android SQLite数据库提取并存储到数组_course

开发过程中需要将蓝牙设备传给手机的数据存储下来，并能将数据存储在数组中，利用数组中的数据，我需要去描点画图。现在数据库已经创建成功，并且能够存储数据了，但是从数据库提取数据的时候，就无法运行，请大神指教 ``` private SaveDatabaseHelper dbHelper; ArrayList<String> dataList = new ArrayList<String>(); ... dbHelper = new SaveDataHelper(this,"Data.db",null,1); dbHelper.getWritableDatabase(); ContentValues values = new ContentValues(); values.put("data",data);//data值由蓝牙传入 dbHelper.insert(values); Cursor cursor = dbHelper.query(new String[]{"data"},"data = ?",null,null,null,null); if(cursor != null && cursor.getCount() >0){ while(cursor.moveToNext()){ for(int i = 0 ; i < cursor.getCount();i++){ String data = cursor.getString(cursor.getColumnIndex("data")); dataList.add(data); } } cursor.close(); } ``` 代码是这些，但是程序运行到insert方法之后就没有继续往下运行了，直接跳过了，不知道是什么原因，数据库这边我基础很弱，还请大神指导

安卓开发中如何使用LitePal将数据库数据显示在Listview_course

如题，我用的是LitePal对数据库进行操作，想将数据显示在ListView中，但是不清楚具体的步骤和操作。

listview显示数据库。怎么Listview每行 做个标志（识）_course

[code="java"] /* 更行试图显示 */ public void UpdataAdapter() { // 获取数据库Phones的Cursor Cursor cur = m_MyDataBaseAdapter.fetchAllData(); miCount=0; List<Map<String, Object>> data = new ArrayList<Map<String,Object>>(); Map<String,Object> item; int i=0; if (cur.moveToFirst()) { do { item = new HashMap<String,Object>(); item.put("time","剩余"+cur.getString(1)+"小时"+cur.getString(2)+"分钟"); item.put("message",cur.getString(3)+"--id:"+cur.getString(0)); data.add(item); miCount++; } while (cur.moveToNext()); } if (cur != null && cur.getCount() >= 0) { // SimpleAdapter是ListView和ArrayList的桥梁,构造listview对象 SimpleAdapter adapter = new SimpleAdapter(this, data, android.R.layout.simple_list_item_2, new String[]{"time","message"}, // 与NAME和NUMBER对应的Views new int[] { android.R.id.text1, android.R.id.text2 }); /* 将adapter添加到m_ListView中 */ m_ListView.setAdapter(adapter); // m_ListView.setTag(cur.getString(0)); } } [/code]

数据库中遍历 问题。。。。。。。。。。_course

[code="java"] public List<Map<String, Object>> findMovieByRegion(String region){ List<Map<String, Object>> movieList = new ArrayList<Map<String, Object>>(); SQLiteDatabase db = dbHelper.getReadableDatabase(); Cursor cursor = db.rawQuery("select num from Online_movie where region=?", new String[]{region}); while(cursor.moveToNext()){ int aa = cursor.getInt(cursor.getColumnIndex("num")); HashMap<String, Object> map = new HashMap<String, Object>(); map.put("aaa", aa); System.out.println(map); movieList.add(map); } return movieList; } //______________________________________________ 下面是 遍历上面 数据库中的 集合 MovieService ms = new MovieService(this.getBaseContext()); List<Map<String,Object>> typenum = ms.findMovieByRegion("美国"); for (Iterator<Map<String, Object>> typeiterator = typenum.iterator(); typeiterator.hasNext();) { Object num = typeiterator.next(); //这里打印的 num 是{aaa=10},{aaa=9},{aaa=3}可是 我只想得到 10,9,3这几个数字 因为 有花括号的话 组成的路径就是错误的 Log.v("num===ggggggggggggggg>", ""+num); listmap = FileList.findFile(Environment.getExternalStorageDirectory()+"/Pictures/"+num+".jpg"); } [/code]

cursorwindow数据库并发读写_course

现在有一个listview，绑定一个adapter，在adapter里根据position，用cursor去获取数据库中一个表TB的数据，假设表中有200行数据。屏幕可以显示10行listview的item，现在滑到了list底部，这个时候还有一个按钮，按下的时候开启一个新线程1，在这个新线程里删掉了表TB最末尾20行数据， 于是在线程1里用Message传一个消息， 让UI主线程里的handler去更换cursor，调adapter的notifydatasetchanged()，更新listview， 那么问题来了，如果在线程1里，删掉数据后，传递消息前，我向上滑了一下listview 那么这个时候会调用adapter的getview，position为200-10=190，调用cursor的movetoposition(190)，然后getString(); 此时，cursorwindow里数据只有0-179条数据，但我却请求了第190条数据，会引发一个cursorwindow的异常，大概是can not get row 190 in a cursor window of 180 rows. 要怎么避免这个异常，或者怎么做到及时更新我的cursor或cursorwindow呢？

为什么Android studio的通讯录里面有数据但是显示不出来_course

我的程序是从主活动里面打开次活动并且将通讯录里的联系人用List View显示出来。 在主活动中成功打开了次活动但是却显示不出来列表。可是我的通讯录里面是有数据的，通讯录如图：  程序运行图：  下面是次活动的代码： xml设计： ``` <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/contacts_text" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context="cn.edu.jluzh.sy06_contacts.ContactsText"> <ListView android:layout_width="match_parent" android:layout_height="match_parent" android:id="@+id/contacts_view" android:layout_alignParentLeft="true" android:layout_alignParentStart="true" /> </RelativeLayout> ``` MaintActivity代码块： ``` public class ContactsText extends AppCompatActivity { ArrayAdapter<String> adapter; List<String> contactsList = new ArrayList<>();//列表的字段 @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.contacts_text); ListView contactsView = (ListView) findViewById(R.id.contacts_view);//列表 adapter = new ArrayAdapter<String>(ContactsText.this, android.R.layout.simple_list_item_1,contactsList); contactsView.setAdapter(adapter); //查看用户是否已授权 if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_CONTACTS) != PackageManager.PERMISSION_GRANTED) {//不授 ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_CONTACTS},1);//返回一个申请的对话框，无论什么结果都会回到第三个函数 } else {//授权的话直接打开 readContacts(); } } private void readContacts() { Cursor cursor = null; StringBuilder stringBuilder = null; try { cursor = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null, null, null, null); if (cursor != null) { while (cursor.moveToFirst()) { //get name String displayName = cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME)); //get number String number = cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER)); String contact = (stringBuilder.append(displayName).append("/n").append(number)).toString(); contactsList.add(contact); } adapter.notifyDataSetChanged(); } } catch (Exception e) { e.printStackTrace(); } finally { if (cursor != null) { cursor.close(); } } } private void OnRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) { //（请求码，申请的权限名，授权结果 switch (requestCode) { case 1: if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) { readContacts(); } else { Toast.makeText(this, "You denied the permission", Toast.LENGTH_SHORT).show(); } break; default: } } } ``` 求大神指点啊，我哭了，秃头少女真的找不到原因a

我想把SQLite数据库里的数据显示到ListView上，代码有什么问题吗？_course

private ListView listview = null; private List<Map<String, Object>> list = new ArrayList<Map<String, Object>>(); private SimpleAdapter simpleAdapter = null; private ImageView iv; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); //适配器添加查询结果，并加到ListView中显示 simpleAdapter = new SimpleAdapter(this, getData(), R.layout.item, new String[] {"name", "waimao","time","contact" ,"image"}, new int[] { R.id.name, R.id.waimao,R.id.time,R.id.contact,R.id.imageView1 }); listview.setAdapter(simpleAdapter); } /** * * @return */ private List<Map<String, Object>> getData() { DBHelper dbHelper = new DBHelper(this); SQLiteDatabase db = dbHelper.getReadableDatabase(); Cursor cursor = db.rawQuery("select * from post", null); while (cursor.moveToNext()) { Integer pid = cursor.getInt(cursor.getColumnIndex("id")); String pname = cursor.getString(cursor.getColumnIndex("name")); String waimao = cursor.getString(cursor.getColumnIndex("waimao")); String time=cursor.getString(cursor.getColumnIndex("time")); String contact=cursor.getString(cursor.getColumnIndex("contact")); //从数据库中提取图片 byte[] pimage=null; pimage=cursor.getBlob(cursor.getColumnIndex("image")); Bitmap imagebitmap=BitmapFactory.decodeByteArray(pimage, 0, pimage.length); iv=(ImageView)findViewById(R.id.imageView1); iv.setImageBitmap(imagebitmap); //这里同样是查询，只不过把查询到的数据添加到list集合，可以参照ListView的用法 Map<String, Object> map = new HashMap<String, Object>(); map.put("id", pid); //获取_id map.put("name", pname); //获取name map.put("waimao", waimao); map.put("time", time); map.put("contact", contact); map.put("image",imagebitmap); list.add(map); } return list; }

如何从sqlite数据库中获取数据并显示在listview中？_course

在登录页面后，我想在listview中把Apple显示成A，Boy显示成B等等，直到F。但是在程序中当我完全登录后，只有登录表成功创建，主菜单还是没有创建。 我想在test database中创建主菜单，然后我想从主菜单表（mainmenu table）中获取数据再显示在listview中。 我使用了下面的代码： if(username.length()>0&&password.length()>0) { SQLiteAdapter db=new SQLiteAdapter(Main.this); db.openToWrite(); if(db.Login(username,password)) { System.out.println("goutham"); Intent intent=new Intent(getApplicationContext(),ExampleActivity.class); startActivity(intent); } SQLiteAdapter.java } public Cursor queueAll() { String[] columns = new String[] { KEY_ID, KEY_CONTENT }; Cursor cursor = sqLiteDatabase.query(MYDATABASE_TABLE, columns, null, null, null, null, null); return cursor; } private static class SQLiteHelper extends SQLiteOpenHelper { public SQLiteHelper(Context context, String name, CursorFactory factory, int version) { super(context, name, factory, version); } @Override public void onCreate(SQLiteDatabase db) { // TODO Auto-generated method stub db.execSQL(SCRIPT_CREATE_DATABASE); db.execSQL(DATABASE_CREATE); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { // TODO Auto-generated method stub } } public long AddUser(String username, String password) { ContentValues initialValues = new ContentValues(); initialValues.put(KEY_USERNAME, username); initialValues.put(KEY_PASSWORD, password); return sqLiteDatabase.insert(DATABASE_TABLE, null, initialValues); } public boolean Login(String username, String password) { // TODO Auto-generated method stub Cursor mCursor = sqLiteDatabase.rawQuery("SELECT * FROM " + DATABASE_TABLE + " WHERE username=? AND password=?", new String[] { username, password }); if (mCursor != null) { if (mCursor.getCount() > 0) { return true; } } return false; } } ExampleActivity.java public class ExampleActivity extends Activity { private SQLiteAdapter mySQLiteAdapter; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); ListView listContent = (ListView) findViewById(R.id.contentlist); /* * Create/Open a SQLite database and fill with dummy content and close * it */ mySQLiteAdapter = new SQLiteAdapter(this); mySQLiteAdapter.openToWrite(); // mySQLiteAdapter.deleteAll(); mySQLiteAdapter.insert("A for Apply"); mySQLiteAdapter.insert("B for Boy"); mySQLiteAdapter.insert("C for Cat"); mySQLiteAdapter.insert("D for Dog"); mySQLiteAdapter.insert("E for Egg"); mySQLiteAdapter.insert("F for Fish"); mySQLiteAdapter.close(); /* * Open the same SQLite database and read all it's content. */ mySQLiteAdapter = new SQLiteAdapter(this); mySQLiteAdapter.openToRead(); Cursor cursor = mySQLiteAdapter.queueAll(); startManagingCursor(cursor); String[] from = new String[] { SQLiteAdapter.KEY_CONTENT }; int[] to = new int[] { R.id.text }; SimpleCursorAdapter cursorAdapter = new SimpleCursorAdapter(this, R.layout.row, cursor, from, to); listContent.setAdapter(cursorAdapter); mySQLiteAdapter.close(); } } 运行程序后，登录表在数据库中创建了，但是主菜单表没有创建。运行程序后，显示一个错误： sqlite returned code=1 no such a table in MY_TABLE

Android开发 简易音乐播放器列表无法显示_course

Android编程，设计一个简易的音乐播放器 主要是通过 ContentResolver 查询 MediaStore 多媒体文件获取文件名，列表显示的。目前真机调试是正常的，可以正常显示列表。 但是在模拟机上调试，列表显示是空白。logcat提示如下截图：  MainActivity.java中代码如下： ``` package com.example.hp.ggmusic; import android.Manifest; import android.content.ContentResolver; import android.content.Context; import android.content.pm.PackageManager; import android.database.Cursor; import android.os.Build; import android.provider.MediaStore; import android.support.annotation.RequiresApi; import android.support.v4.app.ActivityCompat; import android.support.v4.content.ContextCompat; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.view.ViewGroup; import android.widget.CursorAdapter; import android.widget.ListView; import android.widget.MediaController; public class MainActivity extends AppCompatActivity { private final int REQUEST_EXTERNAL_STORAGE= 1; private static String[] PERMISSIONS_STORAGE={ Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE }; private ContentResolver mContentResolver; private ListView mPlaylist; private MediaCursorAdapter mCursorAdapter; //private Cursor mCursor; //音频文件是否属于音乐类型 private final String SELECTION = MediaStore.Audio.Media.IS_MUSIC + " = ?" + " AND " + MediaStore.Audio.Media.MIME_TYPE + " LIKE ?"; //音频文件的MIME类型，MP3对应的是“audio/mpeg” private final String[] SELECTION_ARGS ={ Integer.toString(1), "audio/mpeg"}; // @RequiresApi(api = Build.VERSION_CODES.M) @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mContentResolver=getContentResolver(); //获取本地资源文件列表 mCursorAdapter=new MediaCursorAdapter(MainActivity.this); mPlaylist=findViewById(R.id.lv_playlist); mPlaylist.setAdapter(mCursorAdapter); if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) !=PackageManager.PERMISSION_GRANTED) { if(ActivityCompat.shouldShowRequestPermissionRationale( MainActivity.this, Manifest.permission.READ_EXTERNAL_STORAGE)){ }else { requestPermissions(PERMISSIONS_STORAGE,REQUEST_EXTERNAL_STORAGE); } }else { initPlaylist(); } } public void onRequestPermissionsResult(int requestCode, String[] permissions,int[] grantResults){ switch (requestCode){ case REQUEST_EXTERNAL_STORAGE: if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED){ initPlaylist(); } break; default: break; } } private void initPlaylist(){ //查询本地资源 Cursor mCursor=mContentResolver.query( MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, null, SELECTION, SELECTION_ARGS, MediaStore.Audio.Media.DEFAULT_SORT_ORDER ); mCursorAdapter.swapCursor(mCursor); mCursorAdapter.notifyDataSetChanged(); } } ``` 编写的适配器MediaCursorAdapter.java中的代码如下 ``` package com.example.hp.ggmusic; import android.content.Context; import android.database.Cursor; import android.provider.MediaStore; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.CursorAdapter; import android.widget.TextView; public class MediaCursorAdapter extends CursorAdapter { private Context mContext; private LayoutInflater mLayoutInflater; public MediaCursorAdapter(Context context){ super(context,null,0); mContext=context; mLayoutInflater=LayoutInflater.from(mContext); } @Override public View newView(Context context, Cursor cursor, ViewGroup viewGroup){ View itemView =mLayoutInflater.inflate(R.layout.list_item, viewGroup,false); if (itemView != null){ ViewHolder vh = new ViewHolder(); vh.tvTitle = itemView.findViewById(R.id.tv_title); vh.tvArtist=itemView.findViewById(R.id.tv_artist); vh.tvOrder=itemView.findViewById(R.id.tv_order); vh.divider=itemView.findViewById(R.id.divider); itemView.setTag(vh); return itemView; } return null; } public class ViewHolder{ TextView tvTitle; TextView tvArtist; TextView tvOrder; View divider; } @Override public void bindView(View view, Context context, Cursor cursor) { ViewHolder vh=(ViewHolder) view.getTag(); int titleIndex=cursor.getColumnIndex( MediaStore.Audio.Media.TITLE); int artistIndex=cursor.getColumnIndex( MediaStore.Audio.Media.ARTIST); String title =cursor.getString(titleIndex); String artist =cursor.getString(artistIndex); int position=cursor.getPosition(); if (vh!=null){ vh.tvTitle.setText(title); vh.tvArtist.setText(artist); vh.tvOrder.setText(Integer.toString(position + 1)); } } } ```

点击button实现数据库查询的不同结果，就像有道词典上面，显示释义，隐藏释义_course

想要实现点击button姓名，屏幕NO+序号+姓名，点击学号，屏幕显示NO+序号+学号，实在是不会，请大神帮忙，本人菜鸟，代码都是粘来的,还有啊，我想直接访问在asset下面的数据库，不想有新建，添加数据这个过程，求大神指教 界面：  MainActivity ``` package com.example.shujuku1; import java.util.List; import com.example.shujuku1.Dao.Person; import com.example.shujuku1.Dao.PersonDao; import android.support.v7.app.ActionBarActivity; import android.support.v7.app.ActionBar; import android.support.v4.app.Fragment; import android.graphics.Color; import android.os.Bundle; import android.view.LayoutInflater; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.view.View.OnClickListener; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.Button; import android.widget.ImageView; import android.widget.LinearLayout; import android.widget.ListView; import android.widget.TextView; import android.os.Build; public class MainActivity extends ActionBarActivity { private ListView lv; private List<Person> persons; private Button btn1,btn2; private PersonDao dao; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); lv = (ListView) findViewById(R.id.lv); dao = new PersonDao(this); persons = dao.findAll(); if(persons.size()==0){ dao.add("花花","123456"); dao.add("花花","123456"); dao.add("花花","123456"); dao.add("花花","123456"); dao.add("花花","123456"); dao.add("花花","123456"); dao.add("花花","123456"); lv.setAdapter(new MyListAdapter()); }else if(persons.size()!=0){ lv.setAdapter(new MyListAdapter()); } } ``` Person类 ``` package com.example.shujuku1.Dao; public class Person { int id; String name; String number; public Person() { } public Person(int id, String name, String number) { super(); this.id = id; this.name = name; this.number = number; } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getNumber() { return number; } public void setNumber(String number) { this.number = number; } @Override public String toString() { return " NO." + id + " " + name + ", " + number; } } ``` PersonDao ``` package com.example.shujuku1.Dao; import java.util.ArrayList; import java.util.List; import com.example.shujuku1.PersonSQLiteOpenHelper; import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.location.GpsStatus.Listener; public class PersonDao { private PersonSQLiteOpenHelper helper; public PersonDao(Context context){ helper = new PersonSQLiteOpenHelper(context); } public long add(String name, String number){ SQLiteDatabase db = helper.getWritableDatabase(); ContentValues values = new ContentValues(); values.put("name", name); values.put("number", number); long id = db.insert("person", null, values); db.close(); return id; } public List<Person> findAll(){ SQLiteDatabase db = helper.getWritableDatabase(); List<Person> persons = new ArrayList<Person>(); Cursor cursor = db.query("person", new String[]{"id","name","number"}, null, null, null, null, null); while(cursor.moveToNext()){ int id = cursor.getInt(cursor.getColumnIndex("id")); String name = cursor.getString(cursor.getColumnIndex("name")); String number = cursor.getString(cursor.getColumnIndex("number")); Person p = new Person(id, name, number); persons.add(p); } cursor.close(); db.close(); return persons; } public List<Person> findYingwen(){ SQLiteDatabase db = helper.getWritableDatabase(); List<Person> persons = new ArrayList<Person>(); Cursor cursor = db.query("person", new String[]{"id","name"}, null, null, null, null, null); while(cursor.moveToNext()){ int id = cursor.getInt(cursor.getColumnIndex("id")); String name = cursor.getString(cursor.getColumnIndex("name")); String number = null; Person p = new Person(id, name, number ); System.out.println(cursor.toString()); persons.add(p); } cursor.close(); db.close(); return persons; } public List<Person> findFanyi(){ SQLiteDatabase db = helper.getWritableDatabase(); List<Person> persons = new ArrayList<Person>(); Cursor cursor = db.query("person", new String[]{"id","number"}, null, null, null, null, null); //Cursor cursor = db.execSQL("select id,name from person"); while(cursor.moveToNext()){ int id = cursor.getInt(cursor.getColumnIndex("id")); String number = cursor.getString(cursor.getColumnIndex("number")); String name = null; Person p = new Person(id, name ,number); persons.add(p); } cursor.close(); db.close(); return persons; } } ```

运行 SQLite 数据库后程序崩溃_course

我设计的是查询数据库后下面的程序段返回一个数组。但是现在运行下面的程序时，奔溃了 //info 是类型数据中对象的名字 info.open(); String[] data = info.queryAll(); info.close(); 数据库代码部分，我想检索某一列中所有数据库的行 public String[] queryAll() { String[] columns = new String[] { KEY_NAME }; Cursor cursor = ourDatabase.query(DATABASE_TABLE, columns, null, null, null, null, null); if (cursor != null) { try { final int nameColumnIndex = cursor.getColumnIndex(KEY_NAME); List<String> names = new ArrayList<String>(); while (cursor.moveToNext()) { names.add(cursor.getString(nameColumnIndex)); } return names.toArray(new String[names.size()]); } finally { cursor.close(); } } return null; } 是因为数据库刚开始是空的吗? LOGCAT 04-23 22:26:47.780: E/AndroidRuntime(2825): FATAL EXCEPTION: main 04-23 22:26:47.780: E/AndroidRuntime(2825): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.contactlist/com.example.contactlist.Contacts}: android.database.sqlite.SQLiteException: no such table: mycontacts (code 1): , while compiling: SELECT Contact_name FROM mycontacts 04-23 22:26:47.780: E/AndroidRuntime(2825): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059) 04-23 22:26:47.780: E/AndroidRuntime(2825): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084) 04-23 22:26:47.780: E/AndroidRuntime(2825): at android.app.ActivityThread.access$600(ActivityThread.java:130) 04-23 22:26:47.780: E/AndroidRuntime(2825): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195) 04-23 22:26:47.780: E/AndroidRuntime(2825): at android.os.Handler.dispatchMessage(Handler.java:99) 04-23 22:26:47.780: E/AndroidRuntime(2825): at android.os.Looper.loop(Looper.java:137) 04-23 22:26:47.780: E/AndroidRuntime(2825): at android.app.ActivityThread.main(ActivityThread.java:4745) 04-23 22:26:47.780: E/AndroidRuntime(2825): at java.lang.reflect.Method.invokeNative(Native Method) 04-23 22:26:47.780: E/AndroidRuntime(2825): at java.lang.reflect.Method.invoke(Method.java:511) 04-23 22:26:47.780: E/AndroidRuntime(2825): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786) 04-23 22:26:47.780: E/AndroidRuntime(2825): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 04-23 22:26:47.780: E/AndroidRuntime(2825): at dalvik.system.NativeStart.main(Native Method) 04-23 22:26:47.780: E/AndroidRuntime(2825): Caused by: android.database.sqlite.SQLiteException: no such table: mycontacts (code 1): , while compiling: SELECT Contact_name FROM mycontacts 04-23 22:26:47.780: E/AndroidRuntime(2825): at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method) 04-23 22:26:47.780: E/AndroidRuntime(2825): at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:882) 04-23 22:26:47.780: E/AndroidRuntime(2825): at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:493) 04-23 22:26:47.780: E/AndroidRuntime(2825): at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588) 04-23 22:26:47.780: E/AndroidRuntime(2825): at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58) 04-23 22:26:47.780: E/AndroidRuntime(2825): at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:37) 04-23 22:26:47.780: E/AndroidRuntime(2825): at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:44) 04-23 22:26:47.780: E/AndroidRuntime(2825): at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1314) 04-23 22:26:47.780: E/AndroidRuntime(2825): at android.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1161) 04-23 22:26:47.780: E/AndroidRuntime(2825): at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1032) 04-23 22:26:47.780: E/AndroidRuntime(2825): at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1200) 04-23 22:26:47.780: E/AndroidRuntime(2825): at com.example.contactlist.DBContact.queryAll(DBContact.java:97) 04-23 22:26:47.780: E/AndroidRuntime(2825): at com.example.contactlist.Contacts.onCreate(Contacts.java:38) 04-23 22:26:47.780: E/AndroidRuntime(2825): at android.app.Activity.performCreate(Activity.java:5008) 04-23 22:26:47.780: E/AndroidRuntime(2825): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079) 04-23 22:26:47.780: E/AndroidRuntime(2825): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023) 04-23 22:26:47.780: E/AndroidRuntime(2825): ... 11 more

求大神，安卓中，如何动态更新ListView？_course

我在listview中的点击长按事件中删除了一条数据，就是在sqlite里删掉了，怎么能立即刷新listview呢？ listview我用cursorAdapter 求大神解答，谢谢了，没有c币了，实在不好意思~ ``` package com.chase.cn.demon; import android.app.Activity; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.os.Bundle; import android.os.Handler; import android.util.Log; import android.view.View; import android.widget.AdapterView; import android.widget.ListView; import android.widget.SimpleCursorAdapter; import android.widget.Toast; /** * Created by Chase on 2016/11/10. */ public class BillActivity extends Activity { private ListView billListView; private MySQLiteOpenHelper sqLiteOpenHelper; private SQLiteDatabase mDataBase; private SimpleCursorAdapter billAdapter; private boolean flag = true; // 存储数据的数组列表 // ArrayList<HashMap<String, Object>> listData; // 适配器 @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.bill); sqLiteOpenHelper = new MySQLiteOpenHelper(BillActivity.this, "finance.db", null, 1); mDataBase = sqLiteOpenHelper.getReadableDatabase(); final Cursor c = mDataBase.rawQuery("select * from finance", null); Log.i("database", "data" + mDataBase.isOpen()); billListView = (ListView) findViewById(R.id.bill_listView); billAdapter = new SimpleCursorAdapter(BillActivity.this, R.layout.bill_item, c, // ListItem的XML实现 // 动态数组与Item对应的子项 new String[]{"Time", "Fee", "Budget", "Type"}, // ImageItem的XML文件里面的一个ImageView,两个TextView ID new int[]{R.id.billItem_time, R.id.billItem_money, R.id.billItem_budget, R.id.billItem_type}); billListView.setAdapter(billAdapter); //item监听 billListView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() { @Override public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) { String cc = c.getString(c.getColumnIndex("_id")); //用cursor得到对应表中的id Log.i("info", "cc= " + cc); Toast.makeText(BillActivity.this, "删除了", Toast.LENGTH_SHORT).show(); //删除表中的对应id的行 mDataBase.execSQL("delete from finance where _id=" + cc); ```

如何在Sqlite数据库中插入数据列表？_course

我创建了一个简单的数据库用来插入数据库列表，但是当我想把数据发送到数据库时，有下面的错误： 08-28 15:30:43.015: ERROR/Database(822): Failure 1 (no such column: Sharma) on 0x276e50 when preparing 'INSERT INTO friends Values(Sharma,SaiGeetha,18);"" 相关的代码: sampleDB = this.openOrCreateDatabase(SAMPLE_DB_NAME, MODE_PRIVATE, null); ArrayList<String>FirstName = new ArrayList<String>(); ArrayList<String>LastName = new ArrayList<String>(); ArrayList<Integer >Age = new ArrayList<Integer>(); FirstName.add("SaiGeetha"); FirstName.add("Vivek"); FirstName.add("Rahul"); LastName.add("Sharma"); LastName.add("Lilani"); LastName.add("Lami"); Age.add(18); Age.add(20); Age.add(23); sampleDB.execSQL("CREATE TABLE IF NOT EXISTS " + SAMPLE_TABLE_NAME + " (LastName VARCHAR, FirstName VARCHAR," + " Age INT(3));"); for(int i=0;i<3;i++) { sampleDB.execSQL("INSERT INTO " + enter code here SAMPLE_TABLE_NAME + " Values("+LastName.get(i)+","+FirstName.get(i)+","+Age.get(i)+");"+"\"\""); } /*sampleDB.execSQL("INSERT INTO " + SAMPLE_TABLE_NAME + " Values ('Makam','Sai Geetha','India',25);"); sampleDB.execSQL("INSERT INTO " + SAMPLE_TABLE_NAME + " Values ('Chittur','Raman','India',25);"); sampleDB.execSQL("INSERT INTO " + SAMPLE_TABLE_NAME + " Values ('Solutions','Collabera','India',20);");*/ Cursor c = sampleDB.rawQuery("SELECT FirstName, Age FROM " + SAMPLE_TABLE_NAME + " where Age > 10 LIMIT 5", null); if (c != null ) { if (c.moveToFirst()) { do { String firstName = c.getString(c.getColumnIndex("FirstName")); int age = c.getInt(c.getColumnIndex("Age")); Log.e("---LIST FROM DATABASE--","---VALUE---"+firstName); Log.e("---LIST FROM DATABASE--","---VALUE---"+age ); }while (c.moveToNext()); } } sampleDB.close(); } catch (SQLiteException se ) { Log.e(getClass().getSimpleName(), "Could not create or Open the database"); } finally { if (sampleDB != null) sampleDB.execSQL("DELETE FROM " + SAMPLE_TABLE_NAME); sampleDB.close(); } } 哪里的问题呢?

安卓 cursoradapter 获取某一个value在listview中的位置_course

cursor 从数据库里面娶了值放在listview 里 想获取 id为XX的项在listview中的position， 想请教一下 用什么方法呀

Android关于数据库的问题_course

谁帮忙看看，写入是成功了，但是获取的时候就获取不到数据啊！！！ package com.example.MySqlite; import android.app.Activity; import android.content.ContentValues; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.os.Bundle; import android.util.Log; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; public class MyActivity extends Activity { private ArrayList<Map<String, String>> list; private DBHelper dbHelper; /** * Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); dbHelper = new DBHelper(this); getData(); inser(); lookFor(); } private void lookFor() { List<Map<String,String>> map = new ArrayList<Map<String, String>>(); SQLiteDatabase database = dbHelper.getReadableDatabase(); Cursor cursor = database.query("notes",null,null,null,null,null,null); while(cursor!=null && cursor.getCount()>0){ Map<String,String> has = new HashMap<String, String>(); String name =cursor.getString(1); Log.d("NAME",name); String age = cursor.getString(2); String sex =cursor.getString(3); has.put("name",name); has.put("age",age); has.put("sex",sex); map.add(has); } } private void inser() { SQLiteDatabase sql=dbHelper.getWritableDatabase(); for(int i=0;i<list.size();i++){ ContentValues contentValues = new ContentValues(); long id = i; String name = list.get(i).get("name"); String age = list.get(i).get("age"); String sex = list.get(i).get("sex"); contentValues.put("id",id); contentValues.put("name",name); contentValues.put("age",age); contentValues.put("sex",sex); long hasSuccess = sql.insert("notes", null, contentValues); } } private void getData() { list = new ArrayList<Map<String, String>>(); for(int i =0;i<5;i++){ if(i==0){ Map<String,String> map = new HashMap<String, String>(); map.put("name","kity"); map.put("age","25"); map.put("sex","男"); list.add(map); }else if(i==1) { Map<String,String> map = new HashMap<String, String>(); map.put("name","Dave"); map.put("age","21"); map.put("sex","女"); list.add(map); }else if(i==2) { Map<String,String> map = new HashMap<String, String>(); map.put("name","Marces"); map.put("age","26"); map.put("sex","女"); list.add(map); }else if(i==3) { Map<String,String> map = new HashMap<String, String>(); map.put("name","Rose"); map.put("age","12"); map.put("sex","男"); list.add(map); }else if(i==4) { Map<String,String> map = new HashMap<String, String>(); map.put("name","LiLin"); map.put("age","35"); map.put("sex","女"); list.add(map); } } } } package com.example.MySqlite; import android.content.Context; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; /** * Created by on 15-6-4. */ public class DBHelper extends SQLiteOpenHelper { public DBHelper(Context context) { super(context,"mynote.db",null,1); } @Override public void onCreate(SQLiteDatabase db) { db.execSQL("create table if not exists notes(" + " id long key," + " name varchar(255)," + " age varchar(255)," + " sex varchar(255))"); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { } }

在 ListView 中使用 CursorAdapter 移除一个选择项目_course

我设置了下面的 adapter 类，包含 CursorAdapter 方法。在列表中包含两个文本视图，并在每行设置一个按钮。现在点击按钮时，我想从 list 中删除选择的项目，同时在数据库中也删除。 如何从数据库中获得选项的id，那样我就可以删除选项，然后告知adapter，刷新list。 public class MyAdapter extends CursorAdapter { Cursor c; LayoutInflater inflater; Context context; private String TAG = getClass().getSimpleName(); public MyAdapter(Context context, Cursor c) { super(context, c); this.c = c; this.context = context; inflater = LayoutInflater.from(context); } @Override public void bindView(View view, Context context, final Cursor cursor) { TextView txtName = (TextView) view.findViewById(R.id.txt_name); txtName.setText(cursor.getString(cursor.getColumnIndex(Helper.tbl_col_username))); TextView txtPassword = (TextView) view.findViewById(R.id.txt_password); txtPassword.setText(cursor.getString(cursor.getColumnIndex(Helper.tbl_col_password))); Button button = (Button) view.findViewById(R.id.btn_delete); button.setOnClickListener(new OnClickListener() { public void onClick(View arg0) { Log.d(TAG, "Button Click "); } }); } @Override public View newView(Context context, Cursor cursor, ViewGroup parent) { View v = inflater.inflate(R.layout.row, null); return v; } }