Android开发之焦点事件的使用

.xml

<LinearLayout 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:orientation="vertical"

    tools:context=".MainActivity" >

    <EditText

        android:id="@+id/edit1"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:text="请输入要查询的内容"/>

    

    <EditText

        android:id="@+id/edit2"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:text="www.aizhouliu.com"/>

    

    <TextView

        android:id="@+id/txt"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"/>

</LinearLayout>

.java

public class MainActivity extends Activity {

private EditText et1=null;

private TextView txt=null;

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

this.et1=(EditText) super.findViewById(R.id.edit1);

this.txt=(TextView) super.findViewById(R.id.txt);

this.et1.setOnClickListener(new OnclickListenerImp());

//为我们的编辑框添加焦点事件

this.et1.setOnFocusChangeListener(new OnFocusChangeListenerImp());

}

private class OnclickListenerImp implements OnClickListener{

public void onClick(View v) {

//当点击文本框的时候，清空其中的内容

MainActivity.this.et1.setText("");

}

}

private class OnFocusChangeListenerImp implements OnFocusChangeListener{

public void onFocusChange(View v, boolean hasFocus) {

if(hasFocus){

MainActivity.this.txt.setText("获取焦点");

}

else{

MainActivity.this.txt.setText("文本输入框失去焦点");

}

}

}

}