自定义ViewGroup（可横向、可纵向、可两者皆可）

attrs.xml文件

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="MyViewGroup04">
        <attr name="orientation" format="integer"/>
        <attr name="ori" format="enum">
            <enum name="horizontal" value="1"></enum>
            <enum name="vertical" value="0"></enum>
            <enum name="all" value="2"></enum>
        </attr>
    </declare-styleable>
</resources>

MyViewGroup04

public class MyViewGroup04 extends ViewGroup {

    private int orientation = 0;
    private final int marginVertical = 20;//间距
    private final int marginHorizontal = 20;//间距
    int mTop = 20;
    int mLeft = 20;

    public MyViewGroup04(Context context) {
        this(context,null);
    }

    public MyViewGroup04(Context context, AttributeSet attrs) {
        this(context, attrs,0);
    }

    public MyViewGroup04(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context, attrs, defStyleAttr);
    }

    private void init(Context context, AttributeSet attrs, int defStyleAttr) {
        TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.MyViewGroup04);//拿到属性文件
        orientation = typedArray.getInt(R.styleable.MyViewGroup04_ori, 0);//得到里面的ID
    }

    @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()+marginVertical;
                totalWidth = childAt.getMeasuredWidth()+mLeft*2;
            }else if (orientation == 1){
                totalWidth += childAt.getMeasuredWidth()+marginHorizontal;
                totalHeight = childAt.getMeasuredHeight()+mTop*2;
            }else if (orientation == 2){
                totalHeight += childAt.getMeasuredHeight()+marginVertical;
                totalWidth += childAt.getMeasuredWidth()+marginHorizontal;
            }
        }

        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.AT_MOST:
                    totalHeight += mTop;
                    break;
                case MeasureSpec.EXACTLY:
                    totalHeight = sizeHeight;
                    break;
            }
        }else if (orientation == 1){
            //横向
            switch (modeWidth){
                case MeasureSpec.AT_MOST:
                    totalWidth += mLeft;
                    break;
                case MeasureSpec.EXACTLY:
                    totalWidth = sizeWidth;
                    break;
            }
        }else if (orientation == 2){
            switch (modeWidth){
                case MeasureSpec.AT_MOST:
                    totalWidth += mLeft;
                    totalHeight += mTop * 2;
                    break;
                case MeasureSpec.EXACTLY:
                    totalWidth = sizeWidth;
                    break;
            }
            //totalHeight += mTop;
        }

        setMeasuredDimension(totalWidth,totalHeight);
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        int childCount = getChildCount();
        int mVertical = marginVertical;
        int top = mTop;
        int mhorizontal = marginHorizontal;
        int left = mLeft;
        for (int i = 0; i < childCount; i++) {
            View childAt = getChildAt(i);
            childAt.layout(left,top,childAt.getMeasuredWidth()+left,childAt.getMeasuredHeight()+top);
            if (orientation == 0){
                top += childAt.getMeasuredHeight()+mVertical;
            }else if (orientation == 1){
                left += childAt.getMeasuredWidth()+mhorizontal;
            }else if (orientation == 2){
                top += childAt.getMeasuredHeight()+mVertical;
                left += childAt.getMeasuredWidth()+mhorizontal;
            }
        }

    }
}