自己定义控件的onMeasure方法具体解释

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
         super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        // super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        // 宽和高的计算模式
        int modeWidth = MeasureSpec.getMode(widthMeasureSpec);
        int modeHeight = MeasureSpec.getMode(heightMeasureSpec);

        //真正的宽和高的数值
        int sizeWidth = MeasureSpec.getSize(widthMeasureSpec);
        int sizeHeigth = MeasureSpec.getSize(heightMeasureSpec);

        measureChildren(widthMeasureSpec, heightMeasureSpec);

        setMeasuredDimension(sizeWidth, sizeHeigth);

    }

ViewGroup.LayoutParams.MATCH_PARENT

ViewGroup.LayoutParams.WRAP_CONTENT

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        // 宽和高的计算模式
        int modeWidth = MeasureSpec.getMode(widthMeasureSpec);
        int modeHeight = MeasureSpec.getMode(heightMeasureSpec);
        //拿到父容器推荐的宽和高
        int sizeWidth = MeasureSpec.getSize(widthMeasureSpec);
        int sizeHeigth = MeasureSpec.getSize(heightMeasureSpec);

<span style="white-space:pre">	</span>//这里測量每个孩子的宽和高
        if (modeWidth == MeasureSpec.ATMOST)
            //sizeWidth = 计算的值
        }
        if (modeHeight == MeasureSpec.ATMOST<span style="font-family: Arial, Helvetica, sans-serif;">)</span>
            //sizeHeigth = 计算的值
        }
        setMeasuredDimension(sizeWidth, sizeHeigth);
    }