7

我想听一个 ScrollView 看它是否在滚动。我使用了 OnTouchListener，效果很好。但是当我想使用 OnKeyListener 或重写 OnKeydown 方法为轨迹球添加兼容性时，它就无法工作。似乎孩子按钮获得焦点会导致问题。

任何解决方案或解决方法来解决这个问题？任何帮助表示赞赏。

以下是一些重现我的问题的演示代码：

public class TestActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    ScrollView scrollView = (ScrollView) findViewById(R.id.scroll_view);
    LinearLayout mainLayout = (LinearLayout) findViewById(R.id.main_layout);

    LinearLayout.LayoutParams wrapParams = new LinearLayout.LayoutParams(
            ViewGroup.LayoutParams.FILL_PARENT,
            ViewGroup.LayoutParams.WRAP_CONTENT);
    for (int i = 0; i < 100; i++) {
        MyItem item = (MyItem) LayoutInflater.from(this).inflate(R.layout.item, null);
        item.setParent(scrollView);
        item.setBackgroundColor(Color.WHITE);
        item.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT,
                LayoutParams.WRAP_CONTENT));
        mainLayout.addView(item, wrapParams);
    }

    scrollView.setOnTouchListener(new OnTouchListener() {

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            // can go into here
        }

    });

    scrollView.setOnKeyListener(new OnKeyListener() {

        @Override
        public boolean onKey(View v, int keyCode, KeyEvent event) {
            if (keyCode == KeyEvent.KEYCODE_DPAD_DOWN || keyCode == KeyEvent.KEYCODE_DPAD_DOWN) {
                // never go in, unless no child button get focus
            }
            return false;
        }
    });
}

}

主.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical">
    <com.fannyxie.MyScroller 
        android:id="@+id/scroll_view"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:descendantFocusability="beforeDescendants"
        android:clickable="true"
        android:focusable="true">
        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:orientation="vertical">
            <LinearLayout android:id="@+id/main_layout"
                android:layout_width="fill_parent"
                android:layout_height="fill_parent"
                android:orientation="vertical">
            </LinearLayout>
        </LinearLayout>
    </com.fannyxie.MyScroller>
</LinearLayout>

项目.xml：

<?xml version="1.0" encoding="utf-8"?>
<com.fannyxie.MyItem xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical">
    <TextView 
       android:layout_width="fill_parent"
       android:layout_height="wrap_content"
       android:text="TITLE"/>
    <Button android:layout_width="wrap_content" android:layout_height="wrap_content"
        android:id="@+id/myButton" android:text="Button"></Button>
</com.fannyxie.MyItem>

MyScroller.java

public class MyScroller extends ScrollView {

    public MyScroller(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        //not go into here...
        Log.i("MyScroller", "onKeyDown");
        return super.onKeyDown(keyCode, event);
    }

    @Override
    public boolean onTrackballEvent(MotionEvent event) {
        //not go into here...
        Log.i("MyScroller", "onTrackballEvent");
        return super.onTrackballEvent(event);
    }

    @Override
    protected boolean onRequestFocusInDescendants(int direction,
            Rect previouslyFocusedRect) {
        //some times go into here, when no button get the focus when entering first time
        Log.i("MyScroller", "request focus in descendants");
        return super.onRequestFocusInDescendants(direction, previouslyFocusedRect);
    }



}

MyItem.java

public class MyItem extends LinearLayout {

    private Button myButton;
    public MyItem(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    protected boolean onRequestFocusInDescendants(int direction,
            Rect previouslyFocusedRect) {
        // never go into here
        Log.i("MyItem", "request focus in descendants");
        return super.onRequestFocusInDescendants(direction, previouslyFocusedRect);
    }

}
4

2 回答 2

8

谢谢@杰弗里。但我找到了一个更好的方法来做到这一点。只需覆盖 ScrollView 中的 dispatchkeyevent 方法并在那里处理轨迹球/键盘事件。它运作良好。

public class MyScroller extends ScrollView {

public MyScroller(Context context, AttributeSet attrs) {
    super(context, attrs);
}

@Override
public boolean dispatchKeyEvent(KeyEvent event) {
    if ((KeyEvent.KEYCODE_DPAD_UP == event.getKeyCode() || KeyEvent.KEYCODE_DPAD_DOWN == event.getKeyCode())) {
            //handle key events here
    }
    return super.dispatchKeyEvent(event);
}

}
于 2012-07-12T09:08:17.040 回答
0

触摸事件从子级传递给父级。如果任何孩子消耗了偶数（返回真），那么它就会停止；它不会传递给父级。所以，2个解决方案，

首先是扩展视图容器类并覆盖onInterceptTouchEvent()。这是我为它做的一个例子TabHost，但对你来说它可能是LinearLayout，或者其他什么，

public class FlingableTabHost extends TabHost {
    private GestureDetector gestureDetector;

    public FlingableTabHost(Context context, AttributeSet attrs) {
        super(context, attrs);
        initGestureListener();
    }

    public FlingableTabHost(Context context) {
        super(context);
        initGestureListener();
    }

    public boolean onInterceptTouchEvent(MotionEvent event){
        super.onInterceptTouchEvent(event);
        // handle touch event. only return true if you handle it yourself here.
    }
}

第二种方法是将所有子视图的触摸监听设置为您的自定义触摸监听器，

ViewGroup myLayout = ...;
registerTouchListener(myLayout, myTouchListener);

private void registerTouchListener(View view, View.OnTouchListener listener) {
  view.setOnTouchListener(listener);
  if (view instanceof ViewGroup) {
    ViewGroup vg = (ViewGroup)view;
    for (int i = 0, n = vg.getChildCount(); i < n; i++) {
      View v = vg.getChildAt(i);
      registerTouchListener(v, listener);
    }
  }
}
于 2012-07-11T17:14:51.000 回答