Question

当我们点击android mobile的音量减小按钮时，如何将列表项的焦点移动到下方项目。这个代码但是无法关闭焦点。对这个或任何其他替代选择方法的任何帮助。提前谢谢。

    super.onCreate(savedInstanceState);
    // 2. create array adapter
    ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
            android.R.layout.simple_list_item_1, // standard row layout
                                                    // provided by android
            listItemArray);
    // 3. Call setListAdapter
    setListAdapter(adapter);
    listView = getListView();
    listView.setOnKeyListener(new OnKeyListener() {

        @Override
        public boolean onKey(View v, int keyCode, KeyEvent event) {
            // TODO Auto-generated method stub

            switch (keyCode) {
            case KeyEvent.KEYCODE_VOLUME_DOWN:

                ListView list =(ListView)v;
                for (int j=0; j < list.getChildCount(); j++){
                    if(list.getChildAt(j).getBackground().equals(R.color.gray)){
                    list.getChildAt(j).setBackgroundResource(R.color.TRANSPARENT);
                    list.getChildAt(j++).setBackgroundResource(R.color.gray);
                    }else
                        list.getChildAt(0).setBackgroundResource(R.color.gray);
                }
                                    break;
            }           

            return false;
        }
    });

Answer 1

我很难想象onKeyListener如何ListView检测音量键按下。请尝试覆盖dispatchKeyEvent()中的Activity：

@Override
public boolean dispatchKeyEvent(KeyEvent event) {
    switch (event.getKeyCode()) {
        case KeyEvent.KEYCODE_VOLUME_UP:
            Toast.makeText(this, "volume up", Toast.LENGTH_SHORT).show();
            return true;
        case KeyEvent.KEYCODE_VOLUME_DOWN:
            Toast.makeText(this, "volume down", Toast.LENGTH_SHORT).show();
            return true;
        default:
            return super.dispatchKeyEvent(event);
    }
}

单击android中的音量减小按钮时，如何在列表视图中向下移动选择器

1 个答案: