我有一个Activity
,中间有一个大的ImageView
我可以拖到另外4个较小的视图上。小视图与屏幕底部对齐,并且它们必须水平居中,这就是为什么它们必须位于ViewGroup
内(在这种情况下为LinearLayout
)。
问题是:当我尝试将大图像放在任何小图像上时,OnDragListener
永远不会被触发。相反,如果我将监听器设置为LinearLayout
,则会成功触发。
所有相关代码:
activity_main.xml中
<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"
tools:context=".activity.MainActivity">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="@+id/container">
<ImageView
android:id="@+id/image"
android:layout_width="254dp"
android:layout_height="254dp"
android:layout_centerInParent="true" />
</RelativeLayout>
<LinearLayout
android:id="@+id/container"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:orientation="horizontal">
<ImageView
android:id="@+id/goal_1"
style="@style/Goal"
android:src="@drawable/goal_1"/>
<ImageView
android:id="@+id/goal_2"
style="@style/Goal"
android:src="@drawable/goal_2"/>
<ImageView
android:id="@+id/goal_3"
style="@style/Goal"
android:src="@drawable/hand_03"/>
<ImageView
android:id="@+id/goal_4"
style="@style/Goal"
android:src="@drawable/goal_4"/>
</LinearLayout>
</RelativeLayout>
MainActivity.java
public class MainActivity extends BaseActivity {
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
View goal1 = findViewById(R.id.goal_1);
View goal2 = findViewById(R.id.goal_2);
View goal3 = findViewById(R.id.goal_3);
View goal4 = findViewById(R.id.goal_4);
goal1.setOnDragListener(new MyDragListener(1));
goal2.setOnDragListener(new MyDragListener(2));
goal3.setOnDragListener(new MyDragListener(3));
goal4.setOnDragListener(new MyDragListener(4));
ImageView image = (ImageView) findViewById(R.id.image);
image.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View view, MotionEvent motionEvent) {
if (motionEvent.getAction() == MotionEvent.ACTION_DOWN) {
ClipData data = ClipData.newPlainText("", "");
View.DragShadowBuilder shadowBuilder = new View.DragShadowBuilder(view);
view.startDrag(data, shadowBuilder, null, 0);
return true;
} else {
return false;
}
}
});
}
protected class MyDragListener implements View.OnDragListener() {
private final int index;
public MyDragListener(int index) {
this.index = index;
}
@Override
public boolean onDrag(View v, DragEvent event) {
switch (event.getAction()) {
case DragEvent.ACTION_DRAG_ENTERED:
Log.d(TAG, "onDrag: entered " + index);
break;
case DragEvent.ACTION_DRAG_EXITED:
Log.d(TAG, "onDrag: exited " + index);
break;
case DragEvent.ACTION_DROP:
Log.d(TAG, "onDrag: drop " + index);
break;
default:
Log.d(TAG, "onDrag: default " + index);
break;
}
return true;
}
}
}
如果我删除LinearLayout当然会触发事件。
有没有办法将监听器传递给其中一个ViewGroup
子视图?