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

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);

}

}