Question

我想在我的应用程序中获取GridView项目大小。我只知道我可以在回调中获得项目大小：

private class GridViewItemSelectedListener implements OnItemSelectedListener {
        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position,
                long id) {
            // TODO Auto-generated method stub
            int viewh = view.getHeight();
            int vieww = view.getWidth();
            Log.d(TAG, view.getWidth() + "," + view.getHeight() + 
                    " > position:(" +view.getX() + " , " + view.getY() + ")");
        }
    }

但我无法在onResume中获取其项目大小，即使我在处理程序中尝试过：

private Handler mHandler = new Handler() {
    @Override
    public void handleMessage(Message msg) {
        super.handleMessage(msg);
        switch(msg.what) {
        case UPDATE_GRIDVIEW:
            View itemView = mGridView.getChildAt(0); //this will return null pointer;
            final FrameLayout.LayoutParams  lp= new FrameLayout.LayoutParams(itemView.getLayoutParams());
            lp.setMargins( -3, 0, 0, 0);
            selectorView.setLayoutParams(lp);   
            break;
        default:
            break;
        }
    }
};

我在onResume方法

中触发了处理程序

@Override
protected void onResume() {
    Message msg = new Message();
    msg.what = UPDATE_GRIDVIEW;
    mHandler.sendMessage(msg);

    super.onResume();
}

我甚至试图调用GridView的方法getSelectedItem（）等...，也无法做到。你能给我一些建议吗，原因是什么？以及如何获得gridview项目大小？

Answer 1

<GridView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:stretchMode="columnWidth" />

所以我们只需要拉伸行。我们可以做的，通过计算当我们知道GridView和rowsCount的高度时应该有多少rowHeight。

public class YourAdapter extends BaseAdapter {

   int rowsCount;

   @Override
   public View getView(int position, View convertView, ViewGroup parent) {

       View itemView = convertView;
       if (itemView == null) {
           itemView = layoutInflater.inflate(R.layout.item_view, parent, false);            
           int height = parent.getHeight();
           if (height > 0) {
               LayoutParams layoutParams = itemView.getLayoutParams();
               layoutParams.height = (int) (height / rowsCount);
           } // for the 1st item parent.getHeight() is not calculated yet       
       }
   }

android如何获取gridview项目大小

1 个答案: