ContentResolver这边的代码：
package com.example.providertest;
import android.net.Uri;
import android.os.Bundle;
import android.app.Activity;
import android.content.ContentValues;
import android.database.Cursor;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MainActivity extends Activity {
private String newId;//声明请求方ContentResolver请求的内容uri的id字段
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button addData=(Button)findViewById(R.id.add_data);
addData.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
Uri uri=Uri.parse("content://com.example.databasetest.provider/book");
ContentValues values=new ContentValues();
values.put("name", "A Clash of Kings");
values.put("author", "George Martin");
values.put("pages",1040);
values.put("price", 22.85);
Uri newUri=getContentResolver().insert(uri, values);
newId=newUri.getPathSegments().get(1);
}
});
Button queryData=(Button)findViewById(R.id.query_data);
queryData.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
Uri uri=Uri.parse("content://com.example.databasetest.provider/book");
Cursor cursor=getContentResolver().query(uri, null, null, null, null);
if(cursor != null){
while(cursor.moveToNext()){
String name=cursor.getString(cursor.getColumnIndex("name"));
String author=cursor.getString(cursor.getColumnIndex("author"));
int pages=cursor.getInt(cursor.getColumnIndex("pages"));
double price=cursor.getDouble(cursor.getColumnIndex("price"));
Log.d("MainActivity","book name is"+name);
Log.d("MainActivity","book author is"+author);
Log.d("MainActivity","book pages is"+pages);
Log.d("MainActivity","book price is"+price);
}
cursor.close();
}
}
});
Button updateData=(Button)findViewById(R.id.update_data);
updateData.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
Uri uri=Uri.parse("content://com.example.databasetest.provider/book/"+newId);
ContentValues values=new ContentValues();
values.put("name", "A Storm of Swords");
values.put("pages", 1216);
values.put("price", 24.05);
getContentResolver().update(uri, values, null, null);
}
});
Button deleteData=(Button)findViewById(R.id.delete_data);
deleteData.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
Uri uri=Uri.parse("content://com.example.databasetest.provider/book/"+newId);
getContentResolver().delete(uri, null, null);
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
ContentProvider这边代码：
package com.example.databasetest;
import android.content.ContentProvider;
import android.content.ContentValues;
import android.content.UriMatcher;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.net.Uri;
public class DatabaseProvider extends ContentProvider {
public static final int BOOK_DIR=0;
public static final int BOOK_ITEM=1;
public static final int CATEGORY_DIR=2;
public static final int CATEGORY_ITEM=3;
public static final String AUTHORITY="com.example.databasetest.provider";
private static UriMatcher uriMatcher;
private MyDatabaseHelper dbHelper;
static{
uriMatcher=new UriMatcher(UriMatcher.NO_MATCH);
uriMatcher.addURI(AUTHORITY, "book", BOOK_DIR);
uriMatcher.addURI(AUTHORITY, "book/#", BOOK_ITEM);
uriMatcher.addURI(AUTHORITY, "category", CATEGORY_DIR);
uriMatcher.addURI(AUTHORITY, "category/#", CATEGORY_ITEM);
}
@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
// TODO Auto-generated method stub
SQLiteDatabase db=dbHelper.getWritableDatabase();
int deletedRows=0;
switch(uriMatcher.match(uri)){
case BOOK_DIR:
deletedRows=db.delete("book", selection, selectionArgs);
break;
case BOOK_ITEM:
String bookId=uri.getPathSegments().get(1);
deletedRows=db.delete("book", "id=?",new String[]{bookId});
break;
case CATEGORY_DIR:
deletedRows=db.delete("Category", selection, selectionArgs);
break;
case CATEGORY_ITEM:
String categoryId=uri.getPathSegments().get(1);
deletedRows=db.delete("Category", "id=?",new String[]{categoryId});
break;
default:
break;
}
return deletedRows;
}
@Override
public String getType(Uri uri) {
// TODO Auto-generated method stub
switch(uriMatcher.match(uri)){
case BOOK_DIR:
return "vnd.android.cursor.dir/vnd.com.example.databasetest.provider.book";
case BOOK_ITEM:
return "vnd.android.cursor.item/vnd.com.example.databasetest.provider.book";
case CATEGORY_DIR:
return "vnd.android.cursor.dir/vnd.com.example.databasetest.provider.category";
case CATEGORY_ITEM:
return "vnd.android.cursor.item/vnd.com.example.databasetest.provider.category";
}
return null;
}
@Override
public Uri insert(Uri uri, ContentValues values) {
// TODO Auto-generated method stub
SQLiteDatabase db=dbHelper.getWritableDatabase();
Uri uriReturn=null;
switch(uriMatcher.match(uri)){
case BOOK_DIR:
case BOOK_ITEM:
long newBookId=db.insert("book", null, values);//返回值是新添加的那一行的ID
uriReturn=Uri.parse("content://"+AUTHORITY+"/book/"+newBookId);
break;
case CATEGORY_DIR:
case CATEGORY_ITEM:
long newCategoryId=db.insert("Category", null, values);
uriReturn=Uri.parse("content://"+AUTHORITY+"/category/"+newCategoryId);
break;
default:
}
return uriReturn;
}
@Override
public boolean onCreate() {
// TODO Auto-generated method stub
dbHelper=new MyDatabaseHelper(getContext(), "BookStore.db", null, 2);
return true;
}
@Override
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
String sortOrder) {
// TODO Auto-generated method stub
SQLiteDatabase db=dbHelper.getWritableDatabase();
Cursor cursor=null;
switch(uriMatcher.match(uri)){
case BOOK_DIR:
cursor=db.query("book",projection, selection, selectionArgs, null, null, sortOrder);
break;
case BOOK_ITEM:
String bookId=uri.getPathSegments().get(1);
cursor=db.query("book", projection, "id=?", new String[]{bookId}, null, null, sortOrder);
break;
case CATEGORY_DIR:
cursor=db.query("Category",projection, selection, selectionArgs, null, null, sortOrder);
break;
case CATEGORY_ITEM:
String categoryId=uri.getPathSegments().get(1);
cursor=db.query("Category", projection, "id=?", new String[]{categoryId}, null, null, sortOrder);
break;
default:
break;
}
return cursor;
}
@Override
public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
// TODO Auto-generated method stub
SQLiteDatabase db=dbHelper.getWritableDatabase();
int updatedRows=0;
switch(uriMatcher.match(uri)){
case BOOK_DIR:
updatedRows=db.update("book", values, selection, selectionArgs);
break;
case BOOK_ITEM:
String bookId=uri.getPathSegments().get(1);
updatedRows=db.update("book", values, "id=?", new String[]{bookId});
break;
case CATEGORY_DIR:
updatedRows=db.update("Category", values, selection, selectionArgs);
break;
case CATEGORY_ITEM:
String categoryId=uri.getPathSegments().get(1);
updatedRows=db.update("Category", values, "id=?", new String[]{categoryId});
break;
default:
break;
}
return updatedRows;
}
}
运行第一段程序，点击“Add to Book"按钮显示如图：
部分LogCat信息：
