自定义可设置每行最多显示数目，每个子View宽度等分的FlowView

 // 存储所有子View    private List<List<View>> mAllChildViews = new ArrayList<List<View>>();    // 每一行的高度    private List<Integer> mLineHeight = new ArrayList<Integer>();    // 最多的列数  默认设置为4，可以自己另行设置    private int lineMaxColumn = 4;    public FlowView(Context context) {        this(context, null);    }    public FlowView(Context context, AttributeSet attrs) {        this(context, attrs, 0);    }    public FlowView(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);    }

设置最大的列数，最大列数的取值范围为大于1

    public void setLineMaxColumn(int count) {        if (count < 1) {            this.lineMaxColumn = 1;        } else {            this.lineMaxColumn = count;        }    }

首先得到其父容器传入的测量模式和宽高的计算值，然后遍历所有的childView，使用measureChild方法对所有的childView进行测量。然后根据所有childView的测量得出的宽和高得到该ViewGroup如果设置为wrap_content时的宽和高。最后根据模式，如果是MeasureSpec.EXACTLY则直接使用父ViewGroup传入的宽和高，否则设置为自己计算的宽和高。

    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        super.onMeasure(widthMeasureSpec, heightMeasureSpec);        // 父控件传进来的宽度和高度以及对应的测量模式        int sizeWidth = MeasureSpec.getSize(widthMeasureSpec);        int modeWidth = MeasureSpec.getMode(widthMeasureSpec);        int sizeHeight = MeasureSpec.getSize(heightMeasureSpec);        int modeHeight = MeasureSpec.getMode(heightMeasureSpec);        // 如果当前ViewGroup的宽高为wrap_content的情况        int width = getPaddingLeft() + getPaddingRight();// 自己测量的 宽度        int height = getPaddingTop() + getPaddingBottom();// 自己测量的高度        // 记录每一行的宽度和高度        int lineWidth = 0;        int lineHeight = 0;        // 每行中的View的个数        int lineViewCount = 0;        // 每行中View的宽度的最大值        int lineViewMaxWidth = 0;        // 获取子view的个数        int childCount = getChildCount();        for (int i = 0; i < childCount; i++) {            View child = getChildAt(i);            boolean lastChild = i == childCount - 1;            // 不占控件的View跳过            if (child.getVisibility() == View.GONE) {                if (lastChild) {                    width = Math.max(width, lineWidth);                    height += lineHeight;                }                continue;            }            // 测量子View的宽和高            measureChild(child, widthMeasureSpec, heightMeasureSpec);            MarginLayoutParams lp = (MarginLayoutParams) child                    .getLayoutParams();            int childWidthMode = MeasureSpec.AT_MOST;            // 子View占据的宽度            int childWidthSize = child.getMeasuredWidth();            int childHeightMode = MeasureSpec.AT_MOST;            // 子View占据的高度            int childHeightSize = child.getMeasuredHeight();            if (lp.height >= 0) {                childHeightMode = MeasureSpec.EXACTLY;                // childHeightSize = lp.height;            } else if (modeHeight == MeasureSpec.UNSPECIFIED) {                childHeightMode = MeasureSpec.UNSPECIFIED;                childHeightSize = 0;            }            // 测量子View的宽和高            child.measure(MeasureSpec.makeMeasureSpec(childWidthSize,                    childWidthMode), MeasureSpec.makeMeasureSpec(                    childHeightSize, childHeightMode));            int childWidth = child.getMeasuredWidth() + lp.leftMargin                    + lp.rightMargin;            lineViewMaxWidth = lineViewMaxWidth == 0 ? childWidth : Math.max(                    lineViewMaxWidth, childWidth);            // 换行时候            if (lineWidth + childWidth > sizeWidth                    || (lineMaxColumn > 0 && lineViewCount >= lineMaxColumn)                    || (!checkAddCurLineViews(sizeWidth, lineViewMaxWidth,                    lineViewCount))) {                // 对比得到最大的宽度                width = Math.max(width, lineWidth);                // 重置lineWidth                lineWidth = childWidth;                // 记录行高                height += lineHeight;                lineHeight = child.getMeasuredHeight() + lp.topMargin                        + lp.bottomMargin;                lineViewCount = 1;                lineViewMaxWidth = childWidth;            } else {// 不换行情况                // 叠加行宽                lineWidth += childWidth;                // 得到最大行高                lineHeight = Math.max(lineHeight, child.getMeasuredHeight()                        + lp.topMargin + lp.bottomMargin);                lineViewCount++;            }            // 处理最后一个子View的情况            if (lastChild) {                width = Math.max(width, lineWidth);                height += lineHeight;            }        }        // wrap_content        width += getPaddingLeft() + getPaddingRight();        setMeasuredDimension((modeWidth == MeasureSpec.EXACTLY) ? sizeWidth                : width, (modeHeight == MeasureSpec.EXACTLY) ? sizeHeight                : height);        // 显示的大小    }

重新计算当前行中所有的View的宽度，宽度为所有View平分当前的FlowView的宽度

  private void reMeasureLineViews(List<View> lineViews) {        // 当前行的View的个数        int count = lineViews.size();        if (count == 0) {            return;        }        // 当前行中每个View占用的宽度        int itemWidth = (this.getMeasuredWidth() - this.getLeftPaddingOffset() - this                .getRightPaddingOffset()) / count;        for (int i = 0; i < count; i++) {            View child = lineViews.get(i);            MarginLayoutParams lp = (MarginLayoutParams) child                    .getLayoutParams();            int childWidthSize = itemWidth - lp.leftMargin - lp.rightMargin;            int childHeightSize = child.getMeasuredHeight();            child.measure(MeasureSpec.makeMeasureSpec(childWidthSize,                    MeasureSpec.EXACTLY), MeasureSpec.makeMeasureSpec(                    childHeightSize, MeasureSpec.EXACTLY));        }    }

重新测量最后一行

onLayout中完成对所有childView的位置以及大小的指定

   private void reMeasureLineViews(List<View> lineViews, int prveLineViewCount) {        // 当前行的View的个数        int count = lineViews.size();        if (count == 0) {            return;        }        // 只有一行时，设置上一行的个数为最大个数        prveLineViewCount = prveLineViewCount == 0 ? lineMaxColumn                : prveLineViewCount;        // 如果当前行中View的个数大于等于上一行中View的个数时，所有View的宽度为总宽度的平均值        if (prveLineViewCount <= count) {            reMeasureLineViews(lineViews);            return;        }        // 上一行中View的个数为基数并且当前行中View的个数大于上一行中View的个数的一半时，所有View的宽度为总宽度的平均值        else if (prveLineViewCount % 2 == 1                && count > (int) (prveLineViewCount * 1.0 / 2)) {            reMeasureLineViews(lineViews);            return;        }        // 上一行中每个View占用的宽度        int prveItemWidth = (this.getMeasuredWidth()                - this.getLeftPaddingOffset() - this.getRightPaddingOffset())                / prveLineViewCount;        // 当前行中的最大宽度        int lineViewMaxWidth = 0;        for (int i = 0; i < count; i++) {            View child = lineViews.get(i);            MarginLayoutParams lp = (MarginLayoutParams) child                    .getLayoutParams();            lineViewMaxWidth = Math.max(lineViewMaxWidth,                    child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin);        }        // 如果当前行中View的最大宽度大于上一行的平均值时，当前行中每个View的宽度为上一行平均值的2倍，否则为上一行的平均值。        int itemWidth = prveItemWidth;        if (prveItemWidth < lineViewMaxWidth) {            if (prveLineViewCount % 2 == 0                    || count > (int) (prveLineViewCount * 1.0 / 2)) {                reMeasureLineViews(lineViews);                return;            }            itemWidth = 2 * prveItemWidth;        }        for (int i = 0; i < count; i++) {            View child = lineViews.get(i);            MarginLayoutParams lp = (MarginLayoutParams) child                    .getLayoutParams();            int childWidthSize = itemWidth - lp.leftMargin - lp.rightMargin;            int childHeightSize = child.getMeasuredHeight();            child.measure(MeasureSpec.makeMeasureSpec(childWidthSize,                    MeasureSpec.EXACTLY), MeasureSpec.makeMeasureSpec(                    childHeightSize, MeasureSpec.EXACTLY));        }    }

检查是否能够添加到当前行中

   private boolean checkAddCurLineViews(int totalWidth, int maxWidth,                                         int curCount) {        if (totalWidth / (curCount + 1) > maxWidth) {            return true;        }        return false;    }    @SuppressLint("DrawAllocation")    @Override    protected void onLayout(boolean changed, int l, int t, int r, int b) {        mAllChildViews.clear();        mLineHeight.clear();        // 获取当前ViewGroup的宽度        int width = getWidth();        int lineWidth = 0;        int lineHeight = 0;        //        int lineItemMaxWidth = 0;        //        int prevLineViewCount = 0;        // 记录当前行的view        List<View> lineViews = new ArrayList<View>();        int childCount = getChildCount();        for (int i = 0; i < childCount; i++) {            View child = getChildAt(i);            boolean lastChild = i == childCount - 1;            MarginLayoutParams lp = (MarginLayoutParams) child                    .getLayoutParams();            int childWidth = child.getMeasuredWidth();            int childHeight = child.getMeasuredHeight();            // 如果需要换行            if ((lineViews.size() != 0 && childWidth + lineWidth                    + lp.leftMargin + lp.rightMargin > width)                    || (lineMaxColumn > 0 && lineViews.size() >= lineMaxColumn)) {                mAllChildViews.add(lineViews);                // 记录LineHeight                mLineHeight.add(lineHeight);                // 记录当前行的Views                reMeasureLineViews(lineViews);                prevLineViewCount = lineViews.size();                // 重置行的宽高                lineWidth = 0;                lineHeight = childHeight + lp.topMargin + lp.bottomMargin;                // 重置view的集合                lineViews = new ArrayList<View>();                lineItemMaxWidth = 0;            }            lineItemMaxWidth = lineItemMaxWidth == 0 ? childWidth                    + lp.leftMargin + lp.rightMargin : Math.max(                    lineItemMaxWidth, childWidth + lp.leftMargin                            + lp.rightMargin);            if (!checkAddCurLineViews(width, lineItemMaxWidth, lineViews.size())) {                if (lineViews.size() != 0) {                    mAllChildViews.add(lineViews);                }                // 记录LineHeight                mLineHeight.add(lineHeight);                // 记录当前行的Views                reMeasureLineViews(lineViews);                prevLineViewCount = lineViews.size();                // 重置行的宽高                lineWidth = 0;                lineHeight = childHeight + lp.topMargin + lp.bottomMargin;                // 重置view的集合                lineViews = new ArrayList<View>();                lineItemMaxWidth = childWidth + lp.leftMargin + lp.rightMargin;            }            lineWidth += childWidth + lp.leftMargin + lp.rightMargin;            lineHeight = Math.max(lineHeight, childHeight + lp.topMargin                    + lp.bottomMargin);            lineViews.add(child);            if (lastChild) {                // 处理最后一行                mLineHeight.add(lineHeight);                mAllChildViews.add(lineViews);                // 记录当前行的Views                reMeasureLineViews(lineViews, prevLineViewCount);            }        }        // 设置子View的位置        int left = 0;        int top = 0;        // 获取行数        int lineCount = mAllChildViews.size();        for (int i = 0; i < lineCount; i++) {            // 当前行的views和高度            lineViews = mAllChildViews.get(i);            lineHeight = mLineHeight.get(i);            for (int j = 0; j < lineViews.size(); j++) {                View child = lineViews.get(j);                // 判断是否显示                if (child.getVisibility() == View.GONE) {                    continue;                }                MarginLayoutParams lp = (MarginLayoutParams) child                        .getLayoutParams();                int cLeft = left + lp.leftMargin;                int cTop = top + lp.topMargin;                int cRight = cLeft + child.getMeasuredWidth();                int cBottom = cTop + child.getMeasuredHeight();                // 进行子View进行布局                child.layout(cLeft, cTop, cRight, cBottom);                left += child.getMeasuredWidth() + lp.leftMargin                        + lp.rightMargin;            }            left = 0;            top += lineHeight;        }    }

与当前ViewGroup对应的LayoutParams

    @Override    public LayoutParams generateLayoutParams(AttributeSet attrs) {        return new MarginLayoutParams(getContext(), attrs);    }

完整代码下载地址