我在玩UI事件處理,並且發現了一些我無法從Android Dev找到的解釋:我有一個ImageView和一個TextView,每當我觸及ImageView時,TextView都會顯示一條消息。但是,下面的代碼不起作用:Android:onTouch()永遠不會被調用?
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,當我附上一個OnTouchListener在這樣的MyImageView,它確實有效: 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;
}
}
但據我所知,2實現是一樣的(實現一個事件偵聽器) - 做我誤會什麼了嗎?
謝謝Reuben&Jesus :) – hungson175 2010-12-08 11:23:05