Android中EditText的drawableRight属性设置点击事件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"  xmlns:tools="http://schemas.android.com/tools"  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="com.example.drablerighttest.MainActivity" >  <EditText    android:id="@+id/et"    android:layout_width="350dp"    android:layout_height="wrap_content"    android:drawableRight="@drawable/search_clear_pressed"    android:text="@string/hello_world" /></RelativeLayout>

public class MainActivity extends Activity {  private EditText et;  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    et = (EditText) this.findViewById(R.id.et);    et.setOnTouchListener(new OnTouchListener() {      @Override      public boolean onTouch(View v, MotionEvent event) {        // et.getCompoundDrawables()得到一个长度为4的数组，分别表示左右上下四张图片        Drawable drawable = et.getCompoundDrawables()[2];        //如果右边没有图片，不再处理        if (drawable == null)          return false;        //如果不是按下事件，不再处理        if (event.getAction() != MotionEvent.ACTION_UP)          return false;        if (event.getX() > et.getWidth()            - et.getPaddingRight()            - drawable.getIntrinsicWidth()){          et.setText("");        }          return false;      }    });  }}