ListView、GridView与ScrollView嵌套冲突解决

在ScrollView中嵌套一个ListView发现ListView只显示一行多一点的数据，这肯定是ScrollView与ListView冲突导致的，网上看了些资料有些解决方案并不能解决这个冲突，最后在stackoverflow上看到了一个解决方法，最后采用了他这种解决方案，原文是全英文的，简单的翻译下，本人英文不是太好翻译不好的地方还希望大家能指点一二。阅读原文

怎样让ScrollView里面ListView或者GridView的高度得到扩大。

我们都知道嵌套在ScrollView里面的ListView或者GridView会使他们滑动变得困难并且不能高度不能扩大。Androdi也没有提供内置的API来处理这个问题，所以我们需要基于这两点做一些处理。

这个解决方法在stackoverflow Neil Traft的回答。

ExpandableHeightListView

package net.londatiga.android.widget;

import android.util.AttributeSet;
import android.view.ViewGroup;
import android.widget.ListView;
import android.content.Context;

public class ExpandableHeightListView extends ListView
{

boolean expanded = false;

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

public ExpandableHeightListView(Context context, AttributeSet attrs)
{
super(context, attrs);
}

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

public boolean isExpanded()
{
return expanded;
}

@Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
// HACK! TAKE THAT ANDROID!
if (isExpanded())
{
// Calculate entire height by providing a very large height hint.
// But do not use the highest 2 bits of this integer; those are
// reserved for the MeasureSpec mode.
int expandSpec = MeasureSpec.makeMeasureSpec(
Integer.MAX_VALUE >> 2, MeasureSpec.AT_MOST);
super.onMeasure(widthMeasureSpec, expandSpec);

ViewGroup.LayoutParams params = getLayoutParams();
params.height = getMeasuredHeight();
}
else
{
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}

public void setExpanded(boolean expanded)
{
this.expanded = expanded;
}

ExpandableHeightGridView

package net.londatiga.android.widget;

import android.util.AttributeSet;
import android.view.ViewGroup;
import android.widget.GridView;
import android.content.Context;

public class ExpandableHeightGridView extends GridView
{

boolean expanded = false;

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

public ExpandableHeightGridView(Context context, AttributeSet attrs)
{
super(context, attrs);
}

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

public boolean isExpanded()
{
return expanded;
}

@Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
// HACK! TAKE THAT ANDROID!
if (isExpanded())
{
// Calculate entire height by providing a very large height hint.
// But do not use the highest 2 bits of this integer; those are
// reserved for the MeasureSpec mode.
int expandSpec = MeasureSpec.makeMeasureSpec(
Integer.MAX_VALUE >> 2, MeasureSpec.AT_MOST);
super.onMeasure(widthMeasureSpec, expandSpec);

ViewGroup.LayoutParams params = getLayoutParams();
params.height = getMeasuredHeight();
}
else
{
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}

public void setExpanded(boolean expanded)
{
this.expanded = expanded;
}
}

使用方法：

//ListView
ExpandableHeightListView listView = new ExpandableHeightListView(this);

listView.setAdapter(adapter);
listView.setExpanded(true);

//GridView
ExpandableHeightGridView gridView = new ExpandableHeightGridView(this);

gridView.setNumColumns(4);
gridView.setAdapter(adapter);
gridView.setExpanded(true);

正如你看到的，使嵌套在ScrollViewView里面的ListView和GridVew的高度得到扩大，仅仅只需要调用setExapanded（true）方法就行。