自定义ViewGroup

    public class MyViewGroup extends ViewGroup {
     
        private int orientation = 0;
        private final int mMarginVertical = 20;
        private final int mMarginHorizontal = 20;
        int mTop = 20;
        int mLeft = 20;
     
        public MyViewGroup(Context context) {
            this(context, null);
     
        }
     
        public MyViewGroup(Context context, AttributeSet attrs) {
            this(context, attrs, 0);
     
        }
     
        public MyViewGroup(Context context, AttributeSet attrs, int defStyleAttr) {
            this(context, attrs, defStyleAttr, 0);
        }
     
        public MyViewGroup(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
            super(context, attrs, defStyleAttr, defStyleRes);
            init(context, attrs, defStyleAttr, defStyleRes);
        }
     
        private void init(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
            TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.MyViewGroup);
            orientation = typedArray.getInt(R.styleable.MyViewGroup_ori, 0);
        }
     
        @Override
        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
            int totalHeight = 0;
            int totalWidth = 0;
     
            for (int i = 0; i < getChildCount(); i++) {
                View childAt = getChildAt(i);
                measureChild(childAt, widthMeasureSpec, heightMeasureSpec);
     
                if (orientation == 0) {
                    totalHeight += childAt.getMeasuredHeight() + mMarginVertical;
                    totalWidth = childAt.getMeasuredWidth() + mLeft * 2;
                } else if (orientation == 1) {
                    totalWidth += childAt.getMeasuredWidth() + mMarginHorizontal;
                    totalHeight = childAt.getMeasuredHeight() + mTop * 2;
                } else if (orientation == 2) {
     
                    totalHeight += childAt.getMeasuredHeight() + mMarginVertical;
                    totalWidth += childAt.getMeasuredWidth() + mMarginHorizontal;
                }
            }
     
     
            int modeWidth = MeasureSpec.getMode(widthMeasureSpec);
            int sizeWidth = MeasureSpec.getSize(widthMeasureSpec);
     
            int modeHeight = MeasureSpec.getMode(heightMeasureSpec);
            int sizeHeight = MeasureSpec.getSize(heightMeasureSpec);
     
            if (orientation == 0) {
                //纵向
                switch (modeHeight) {
                    case MeasureSpec.EXACTLY:
                        //dp match_parent
                        totalHeight = sizeHeight;
                        break;
                    case MeasureSpec.AT_MOST:
                        //wrap_content
                        totalHeight += mTop;
                        break;
                    case MeasureSpec.UNSPECIFIED:
                        break;
                }
     
            } else if (orientation == 1) {
                //横向
                switch (modeWidth) {
                    case MeasureSpec.EXACTLY:
                        //dp match_parent
                        totalWidth = sizeWidth;
                        break;
                    case MeasureSpec.AT_MOST:
                        //wrap_content
                        totalWidth += mLeft;
                        break;
                    case MeasureSpec.UNSPECIFIED:
                        break;
                }
     
     
            } else if (orientation == 2) {
                switch (modeWidth) {
                    case MeasureSpec.EXACTLY:
                        //dp match_parent
                        totalWidth = sizeWidth;
                        break;
                    case MeasureSpec.AT_MOST:
                        //wrap_content
                        totalWidth += mLeft;
                        totalHeight += mTop * 2;
                        break;
                    case MeasureSpec.UNSPECIFIED:
                        break;
                }
                totalHeight += mTop;
            }
     
     
            setMeasuredDimension(totalWidth, totalHeight);
     
        }
     
        @Override
        protected void onLayout(boolean changed, int l, int t, int r, int b) {
            int childCount = getChildCount();
            int marginVertical = mMarginVertical;
            int top = mTop;
            int marginHorizontal = mMarginHorizontal;
            int left = mLeft;
            for (int i = 0; i < childCount; i++) {
                View childAt = getChildAt(i);
                childAt.layout(0 + left, 0 + top, childAt.getMeasuredWidth() + left, childAt.getMeasuredHeight() + top);
                if (orientation == 0) {
                    top += childAt.getMeasuredHeight() + marginVertical;
                } else if (orientation == 1) {
                    left += childAt.getMeasuredWidth() + marginHorizontal;
                } else if (orientation == 2) {
                    top += childAt.getMeasuredHeight() + marginVertical;
                    left += childAt.getMeasuredWidth() + marginHorizontal;
                }
            }
        }
     
        @Override
        protected void onDraw(Canvas canvas) {
            super.onDraw(canvas);
        }
    }


    attrs.XML文件
     
    <?xml version="1.0" encoding="utf-8"?>
    <resources>
        <declare-styleable name="MyViewGroup">
            <attr name="orientation" format="integer"/>
            <attr name="ori" format="enum">
                <enum name="horizontal" value="1"/>
                <enum name="vertical" value="0"/>
                <enum name= "all" value="2"/>
            </attr>
        </declare-styleable>
    </resources>
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作者：梵韵
来源：CSDN
原文：https://blog.csdn.net/qq_41673194/article/details/79934277
版权声明：本文为博主原创文章，转载请附上博文链接！