我在玩UI事件处理,并且发现了一些我无法从Android Dev找到的解释:我有一个ImageView和一个TextView,每当我触及ImageView时,TextView都会显示一条消息。但是,下面的代码不起作用:Android:onTouch()永远不会被调用?
public class ShowSomething extends Activity {
private LinearLayout ll;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
LinearLayout ll = (LinearLayout)findViewById(R.id.linearLayout);
final TextView textview = (TextView)findViewById(R.id.textview);
MyImageView image = new MyImageView(this, textview);
image.setImageResource(R.drawable.icon);
ll.addView(image, 48, 48);
}
}
而且MyImageView.java
public class MyImageView extends ImageView implements OnTouchListener{
private TextView textview;
public MyImageView(Context context,TextView textview) {
super(context);
this.textview = textview;
}
@Override
public boolean onTouch(View v, MotionEvent event) {
textview.setText("Event captured !");
return true;
}
}
main.xml中
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/linearLayout"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
>
<TextView
android:id="@+id/textview"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Holder"
/>
</LinearLayout>
但是,当我附上一个OnTouchListener在这样的MyImageView,它确实有效: File ShowSomething.java
public class ShowSomething extends Activity {
private LinearLayout ll;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
LinearLayout ll = (LinearLayout)findViewById(R.id.linearLayout);
final TextView textview = (TextView)findViewById(R.id.textview);
MyImageView image = new MyImageView(this,textview);
image.setImageResource(R.drawable.icon);
image.setOnTouchListener(new OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
textview.setText("Event captured!");
return false;
}
});
ll.addView(image, 48, 48);
}
}
和文件MyImageView.java
public class MyImageView extends ImageView {
private TextView textview;
public MyImageView(Context context,TextView textview) {
super(context);
this.textview = textview;
}
}
但据我所知,2实现是一样的(实现一个事件侦听器) - 做我误会什么了吗?
谢谢Reuben&Jesus :) – hungson175 2010-12-08 11:23:05