public class MainActivity extends AppCompatActivity {

private static final String TAG = "jojo";

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Uri uri = Uri.parse("content://sms");
getContentResolver().registerContentObserver(uri, true, new MyContentObserver(new Handler()));
}

// 定义内容观察者
private class MyContentObserver extends ContentObserver {
/**
* Creates a content observer.
*
* @param handler The handler to run {@link #onChange} on, or null if none.
*/
public MyContentObserver(Handler handler) {
super(handler);
}

@Override
public void onChange(boolean selfChange) {
Log.d(TAG, "onChange: 短信的数据库内容发生了改变");
// 把body address date 取出来

super.onChange(selfChange);
}
}
}

发送短息的时候,短信的数据库内容会改变三次

点击发送 ->正在发送->发送成功