Android ViewPager高度无法设置wrap_content

界面需求需要ViewPager并自适应高度，但是设置高度的时候发现“wrap_content”没有效果。

解决方法：
自定义ViewPager，重写ViewPager的onMesure()方法：

public class RouteBusViewPager extends ViewPager {
    public RouteBusViewPager(Context context) {
        super(context);
    }

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

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int height = 0;
        for (int i = 0; i < getChildCount(); i++) {
            View child = getChildAt(i);
            child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
            int h = child.getMeasuredHeight();
            if (h > height) {
                height = h;
            }
        }

        heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);

        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }
}