LinearLayout.onMeasure-设置LinearLayout的高度

    if (!allFillParent && widthMode != MeasureSpec.EXACTLY) {
        maxWidth = alternativeMaxWidth;
    }
    
    maxWidth += mPaddingLeft + mPaddingRight;

    // Check against our minimum width
    maxWidth = Math.max(maxWidth, getSuggestedMinimumWidth());
    
    setMeasuredDimension(resolveSizeAndState(maxWidth, widthMeasureSpec, childState),
            heightSizeAndState);

    if (matchWidth) {
        forceUniformWidth(count, heightMeasureSpec);
    }