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

Posted 2020-06-25 小破孩123

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