ScrollView中嵌套GridView，ListView只顯示一行的解決辦法

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

關於為什麼只顯示一行，個人理解是:如果單獨使用GridView和ListView，裡面的內容是固定的，底層系統很容易計算出控制項要占用的寬高，當外面嵌套一層ScrollView後，就能做上下或左右滑動，但能滑動多少系統不知道，這時就需要你給計算出一個滑動區域給ScrollView。而這個數值就是通過GridView和ListView中的內容總的寬高之和。有更精確的理解歡迎賜教。解決的辦法有兩種：

方法一：就是上面說的通過計算出來ListView或者GridView中的子列高度和 進行顯示：

public void setListViewHeightBasedOnChildren(ListView listView) {    
    ListAdapter listAdapter = listView.getAdapter();     
    if (listAdapter == null) {    
        return;    
    }    
  
    int totalHeight = 0;    
    for (int i = 0; i < listAdapter.getCount(); i++) {    
        View listItem = listAdapter.getView(i, null, listView);    
        listItem.measure(0, 0);    
        totalHeight += listItem.getMeasuredHeight();    
    }    
  
    ViewGroup.LayoutParams params = listView.getLayoutParams();    
    params.height = totalHeight + (listView.getDividerHeight() * (listAdapter.getCount() - 1));    
    ((MarginLayoutParams)params).setMargins(15, 15, 15, 15);  
    listView.setLayoutParams(params);    

}

方法二：重寫GridView和ListView的onMeasure方法，直接給它一個足夠大的高度：

重寫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 >> 2,  
                MeasureSpec.AT_MOST);  
        super.onMeasure(widthMeasureSpec, expandSpec);  
    }  
}

重寫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 >> 2,   
                    MeasureSpec.AT_MOST);   
            super.onMeasure(widthMeasureSpec, expandSpec);   
        }   
}