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