android - getMeasuredHeight() 在 Android 4.2.2 上返回 16777215

Question

我写了一个非常简单的 View 组扩展 LinearLayout 如下。

 @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {



        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        ViewParent viewParent  = getParent();
        if(viewParent instanceof RelativeLayout)
        {
            RelativeLayout parentLayout  = (RelativeLayout)viewParent;

            int widthSize = MeasureSpec.getSize(widthMeasureSpec);


            Log.d(Constants.TAG, "Parent height is " + parentLayout.getMeasuredHeight());
            Log.d(Constants.TAG, "Parent height is1 " + parentLayout.getHeight());
            int height = parentLayout.getMeasuredHeight();
//            getChildAt(0).measure(MeasureSpec.EXACTLY | AndroidUtilities.dp(70), MeasureSpec.EXACTLY | (int)(parentLayout.getMeasuredHeight()*0.6));
 //           getChildAt(1).measure(MeasureSpec.EXACTLY | AndroidUtilities.dp(70), MeasureSpec.EXACTLY | (int)(parentLayout.getMeasuredHeight()*0.4));

            getChildAt(0).measure(MeasureSpec.makeMeasureSpec(AndroidUtilities.dp(70), MeasureSpec.EXACTLY), MeasureSpec.makeMeasureSpec((int)(height* 0.6), MeasureSpec.EXACTLY));
            getChildAt(1).measure(MeasureSpec.makeMeasureSpec(AndroidUtilities.dp(70), MeasureSpec.EXACTLY), MeasureSpec.makeMeasureSpec((int)(height* 0.6), MeasureSpec.EXACTLY));


            setMeasuredDimension(widthSize, parentLayout.getMeasuredHeight());

        }

此 View 组的父级是包含简单 TextView 的 RelativeLayout。

在 Android 4.2.2 上，parentLayout.getMeasuredHeight() 返回 16777215。我无法理解这个数字。它适用于更高版本的 Android。

有人遇到过这个吗？

Answer 1

我还没有看到这个，但是文档中有一个关于适合您的场景的错误的注释:

http://developer.android.com/reference/android/view/View.MeasureSpec.html#makeMeasureSpec(int,%20int)

至于 16777215(等于 2^24 - 1)，我不确定，但它等于 MEASURED_SIZE_MASK 似乎是一个相当大的巧合。见

http://developer.android.com/reference/android/view/View.html#MEASURED_SIZE_MASK