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。看起来像焦点的子按钮导致了问题。
是否有解决此问题的解决方案或变通方法?感谢您的帮助。
这里有一些演示代码可以重现我的问题:
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);
}
}
我的元素.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);
}
}
最佳答案
谢谢@Jeffrey。但我找到了更好的方法。只需覆盖 ScrollView 中的 dispatchkeyevent 方法并在那里处理轨迹球/键盘事件。它运行良好。
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);
}
}
关于android - 如果 subview 获得焦点,则 OnKeyListener 或 OnKeydown 不起作用,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/11437681/