Android 自定义ViewGroup

自定义ViewGroup

类似LinearLayout

onMeasure

 		@Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        ////将所有的子View进行测量，这会触发每个子View的onMeasure函数
        measureChildren(widthMeasureSpec, heightMeasureSpec);
        
        int widthMode = MeasureSpec.getMode(widthMeasureSpec);
        int widthSize = MeasureSpec.getSize(widthMeasureSpec);
        int heightMode = MeasureSpec.getMode(heightMeasureSpec);
        int heightSize = MeasureSpec.getSize(heightMeasureSpec);
        
        int childCount = getChildCount();
        int height = 0; // 子View的高度 相加
        for (int i = 0; i < childCount; i++) {
            View childView = getChildAt(i);
            height += childView.getMeasuredHeight();
        }
        // 类似可以得到高度，
        // 根据mode 设计不同的高度和宽度
        setMeasuredDimension(width, height);
        
    }

onLayout

		@Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        int count = getChildCount();
        int curHeight = t;
        for (int i = 0; i < count; i++) {
            View child = getChildAt(i);
            int height = child.getMeasuredHeight();
            int width = child.getMeasuredWidth();
            //摆放子View，参数分别是子View矩形区域的左、上、右、下边
            child.layout(l, curHeight, l + width, curHeight + height);
            curHeight += height;
        }
    }

使用

<com.xxx.xxx.XXXViewGroup>
// 添加子View
</XXXViewGroup>