android scrollview嵌套listview计算高度的问题

 ScrollView中只能放一个控件，通常都放LinearLayout，orientation属性值为vertical。在LinearLayout中放须要呈现的内容。ListView也在其中，ListView的高度设为适应自身内容（wrap_content）。可是为啥在scrollview中嵌套listview会出现只显示第一条listitem的高度呢，缘由是：scrollview的ontach方法的滚动事件消费处理，ListView控件的高度设定问题

从谷歌那里找到的ScrollView嵌套ListView只显示一行的解决办法相信不少人都遇到过，而后大部分都是用这位博主的办法解决的吧

刚开始我也是用这个办法解决的，首先感谢这位哥的大私奉献，贴上地址

http://blog.csdn.net/p106786860/article/details/10461015

二、解决的核心代码

public void setListViewHeightBasedOnChildren(ListView listView) {     
         // 获取ListView对应的Adapter     
         ListAdapter listAdapter = listView.getAdapter();     
         if (listAdapter == null) {     
             return;     
         }     
 
         int totalHeight = 0;     
         for (int i = 0, len = listAdapter.getCount(); i < len; i++) {     
             // listAdapter.getCount()返回数据项的数目     
             View listItem = listAdapter.getView(i, null, listView);     
             // 计算子项View 的宽高     
             listItem.measure(0, 0);      
             // 统计全部子项的总高度     
             totalHeight += listItem.getMeasuredHeight();      
         }     
 
         ViewGroup.LayoutParams params = listView.getLayoutParams();     
 params.height = totalHeight+ (listView.getDividerHeight() * (listAdapter.getCount() - 1));     
         // listView.getDividerHeight()获取子项间分隔符占用的高度     
         // params.height最后获得整个ListView完整显示须要的高度     
         listView.setLayoutParams(params);     
     }

这个代码让控件去计算Listview本身的高度而后设置这个Listview的高度

可是这个代码里面有一个问题，就是这个当你的ListView里面有多行的TextView的话，ListView的高度就会计算错误，它只算到了一行TextView的高度，

这个问题在so上的概述为如下：

http://stackoverflow.com/questions/14386584/getmeasuredheight-of-textview-with-wrapped-text

三、终极解决办法

这个问题头疼了一阵后，查找了一下，应该重写一个TextView的onMeasure方法比较好解决

代码有

@Override  
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {  
 super.onMeasure(widthMeasureSpec, heightMeasureSpec);  
 
         Layout layout = getLayout();  
 if (layout != null) {  
 int height = (int)FloatMath.ceil(getMaxLineHeight(this.getText().toString()))  
                     + getCompoundPaddingTop() + getCompoundPaddingBottom();  
 int width = getMeasuredWidth();              
             setMeasuredDimension(width, height);  
         }  
     }  
 
 private float getMaxLineHeight(String str) {  
 float height = 0.0f;  
 float screenW = ((Activity)context).getWindowManager().getDefaultDisplay().getWidth();  
 float paddingLeft = ((LinearLayout)this.getParent()).getPaddingLeft();  
 float paddingReft = ((LinearLayout)this.getParent()).getPaddingRight();  
 //这里具体this.getPaint()要注意使用，要看你的TextView在什么位置，这个是拿TextView父控件的Padding的，为了更准确的算出换行  
 int line = (int) Math.ceil( (this.getPaint().measureText(str)/(screenW-paddingLeft-paddingReft))); height = (this.getPaint().getFontMetrics().descent-this.getPaint().getFontMetrics().ascent)*line; return height;}

上面的代码完成更能为，在ListView开始测量时，测量到TextView时，就调用咱们的onMeasure方法，咱们就能够测量字体的总宽度除与去掉边距的屏幕的大小，就能够算出文字要几行来显示，而后测量字体的高度*行数能够获得字体的总高度，而后在加上上下边距就是TextView真正的高度，而后setMeasuredDimension进去就能够计算出正确的值出来。

完整大代码我贴出来

public class MyListView2 extends LinearLayout { private BaseAdapter adapter; private MyOnItemClickListener onItemClickListener; boolean footerViewAttached = false; private View footerview; @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { // TODO Auto-generated method stub super.onLayout(changed, l, t, r, b); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { int expandSpec = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2, MeasureSpec.AT_MOST); super.onMeasure(widthMeasureSpec, expandSpec); } public void notifyChange() { int count = getChildCount(); if (footerViewAttached) { count--; } LayoutParams params = new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT); for (int i = count; i < adapter.getCount(); i++) { final int index = i; final LinearLayout layout = new LinearLayout(getContext()); layout.setLayoutParams(params); layout.setOrientation(VERTICAL); View v = adapter.getView(i, null, null); v.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { if (onItemClickListener != null) { onItemClickListener.onItemClick(MyListView2.this, layout, index, adapter.getItem(index)); } } }); ImageView imageView = new ImageView(getContext()); imageView.setLayoutParams(params); layout.addView(v); layout.addView(imageView); addView(layout, index); } } public MyListView2(Context context) { super(context); initAttr(null); } public MyListView2(Context context, AttributeSet attrs) { super(context, attrs); initAttr(attrs); } public void initAttr(AttributeSet attrs) { setOrientation(VERTICAL); } public void initFooterView(final View footerView) { this.footerview = footerView; } public void setFooterViewListener(OnClickListener onClickListener) { this.footerview.setOnClickListener(onClickListener); } public BaseAdapter getAdapter() { return adapter; } public void setAdapter(BaseAdapter adpater) { this.adapter = adpater; removeAllViews(); if (footerViewAttached) addView(footerview); notifyChange(); } public void setOnItemClickListener(MyOnItemClickListener onClickListener) { this.onItemClickListener = onClickListener; } public void noMorePages() { if (footerview != null && footerViewAttached) { removeView(footerview); footerViewAttached = false; } } public void mayHaveMorePages() { if (!footerViewAttached && footerview != null) { addView(footerview); footerViewAttached = true; } } public static interface MyOnItemClickListener { public void onItemClick(ViewGroup parent, View view, int position, Object o); } }

这个adapter就是你获取数据后设置的，也就是上面两点的综合