寫的幾個專案基本都有ViewPager實現Banner，最開始都是固定高度，讓服務端返回圖片比例控制一下（好低階）。。。

通過LayoutParmas動態改變ViewPager的高度

int viewPagerIndex = main.indexOf(viewPager);
int childViewHeight = getChildViewHeight(); //獲取ViewPager的子View的高度。
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT
 
, childViewHeight );//這裡設定params的高度。
main.removeView(viewPager);
main.addView(viewPager, viewPagerIndex , params);//使用這個param

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);
}