此文章参考http://blog.youkuaiyun.com/jdsjlzx/article/details/45042081
感谢大神提供的帮助 尊重原创
最近碰到个需求 弹窗标签流 弹窗高度有限 但是后台标签超过范围需要嵌套 ScrollView 此文章只是为了解决上面链接嵌套ScrollView无效问题
public class XCFlowLayoutScrollView extends ViewGroup{
//存储所有子View
private List<List<View>> mAllChildViews = new ArrayList<>();
//每一行的高度
private List<Integer> mLineHeight = new ArrayList<>();
public int viewHeight = 0;
public XCFlowLayoutScrollView(Context context) {
this(context, null);
}
public XCFlowLayoutScrollView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public XCFlowLayoutScrollView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
protected void onMeasure(int widthMeasureSpec, int 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);
//如果当前ViewGroup的宽高为wrap_content的情况
int width = 0;//自己测量的 宽度
int height = 0;//自己测量的高度 下面的计算公式存在bug 所以用mLineHeight 替换
//记录每一行的宽度和高度
int lineWidth = 0;
int lineHeight = 0;
//获取子view的个数
int childCount = getChildCount();
for(int i = 0;i < childCount; i ++){
View child = getChildAt(i);
//测量子View的宽和高
measureChild(child, widthMeasureSpec, heightMeasureSpec);
//得到LayoutParams
MarginLayoutParams lp = (MarginLayoutParams) getLayoutParams();
//子View占据的宽度
int childWidth = child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin;
//子View占据的高度
int childHeight = child.getMeasuredHeight() + lp.topMargin + lp.bottomMargin;
//换行时候
if(lineWidth + childWidth > sizeWidth){
//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 = childHeight;
}else{//不换行情况
//叠加行宽
lineWidth += childWidth;
//得到最大行高
lineHeight = Math.max(lineHeight, childHeight);
}
//处理最后一个子View的情况
if(i == childCount -1){
width = Math.max(width, lineWidth);
height += lineHeight;
}
}
//已下只是单独针对ScrollView 一般标签使用 使用上处链接代码即可
viewHeight = 0;
for(int i = 0; i < mLineHeight.size();i++){
viewHeight = mLineHeight.get(i)+ viewHeight;
}
setMeasuredDimension(resolveSize(width, widthMeasureSpec),
resolveSize(viewHeight, heightMeasureSpec));
}
@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;
//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);
MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams();
int childWidth = child.getMeasuredWidth();
int childHeight = child.getMeasuredHeight();
//如果需要换行
if(childWidth + lineWidth + lp.leftMargin + lp.rightMargin > width){
//记录LineHeight
mLineHeight.add(lineHeight);
//记录当前行的Views
mAllChildViews.add(lineViews);
//重置行的宽高
lineWidth = 0;
lineHeight = childHeight + lp.topMargin + lp.bottomMargin;
//重置view的集合
lineViews = new ArrayList();
}
lineWidth += childWidth + lp.leftMargin + lp.rightMargin;
lineHeight = Math.max(lineHeight, childHeight + lp.topMargin + lp.bottomMargin);
lineViews.add(child);
}
//处理最后一行
mLineHeight.add(lineHeight);
mAllChildViews.add(lineViews);
//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);
}
}