ScrollView中嵌套GridView，ListView只显示一行的解决办法

转载：http://blog.csdn.net/luohai859/article/details/39347583

关于为什么只显示一行，个人理解是:如果单独使用GridView和ListView，里面的内容是固定的，底层系统很容易计算出控件要占用的宽高，当外面嵌套一层ScrollView后，就能做上下或左右滑动，但能滑动多少系统不知道，这时就需要你给计算出一个滑动区域给ScrollView。而这个数值就是通过GridView和ListView中的内容总的宽高之和。有更精确的理解欢迎赐教。解决的办法有两种：

方法一：就是上面说的通过计算出来ListView或者GridView中的子列高度和 进行显示：

public void setListViewHeightBasedOnChildren(ListView listView) {
    ListAdapter listAdapter = listView.getAdapter();
    if (listAdapter == null) {
        return;
    }    

    int totalHeight = ;
    for (int i = ; i < listAdapter.getCount(); i++) {
        View listItem = listAdapter.getView(i, null, listView);
        listItem.measure(, );
        totalHeight += listItem.getMeasuredHeight();
    }    

    ViewGroup.LayoutParams params = listView.getLayoutParams();
    params.height = totalHeight + (listView.getDividerHeight() * (listAdapter.getCount() - ));
    ((MarginLayoutParams)params).setMargins(, , , );
    listView.setLayoutParams(params);    

}

方法二：重写GridView和ListView的onMeasure方法，直接给它一个足够大的高度：

重写ListView:

public class MyListView extends ListView {  

    public MyListView(Context context) {
        // TODO Auto-generated method stub
        super(context);
    }  

    public MyListView(Context context, AttributeSet attrs) {
        // TODO Auto-generated method stub
        super(context, attrs);
    }  

    public MyListView(Context context, AttributeSet attrs, int defStyle) {
        // TODO Auto-generated method stub
        super(context, attrs, defStyle);
    }  

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        // TODO Auto-generated method stub
        int expandSpec = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> ,
                MeasureSpec.AT_MOST);
        super.onMeasure(widthMeasureSpec, expandSpec);
    }
}

重写GridView:

public class MyGridView extends GridView{
      public MyGridView(Context context, AttributeSet attrs) {
            super(context, attrs);
        }   

        public MyGridView(Context context) {
            super(context);
        }   

        public MyGridView(Context context, AttributeSet attrs, int defStyle) {
            super(context, attrs, defStyle);
        }   

        @Override
        public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {   

            int expandSpec = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> ,
                    MeasureSpec.AT_MOST);
            super.onMeasure(widthMeasureSpec, expandSpec);
        }
}