流式布局代码块

package sheng.shen.view;import android.content.Context;import android.util.AttributeSet;import android.view.View;import android.view.ViewGroup;import java.util.ArrayList;import java.util.List;/** * Created by SFS on 2017/1/11. * Description : 流式布局 热门标签 */public class FlowLayout 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 FlowLayout(Context context) {        this(context, null);    }    public FlowLayout(Context context, AttributeSet attrs) {        this(context, attrs, 0);    }    public FlowLayout(Context context, AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);    }    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        // TODO Auto-generated method stub        //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 = 0;//自己测量的 宽度        int height = 0;//自己测量的高度        //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;            }        }        //wrap_content        setMeasuredDimension(modeWidth == MeasureSpec.EXACTLY ? sizeWidth : width,                modeHeight == MeasureSpec.EXACTLY ? sizeHeight : height);        super.onMeasure(widthMeasureSpec, heightMeasureSpec);    }    @Override    protected void onLayout(boolean changed, int l, int t, int r, int b) {        // TODO Auto-generated method stub        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);    }}

  在 XML文件中 

<sheng.shen.view.FlowLayoutandroid:id="@+id/flowLayout"android:layout_width="match_parent"android:layout_height="150dp"android:layout_marginLeft="50dp"android:layout_marginRight="50dp"/>
在  Java代码中
FlowLayout mFlowLayout=(FlowLayout)findViewById(R.id.flowLayout);          MarginLayoutParams lp = new MarginLayoutParams(          LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);          lp.leftMargin = 5;          lp.rightMargin = 5;          lp.topMargin = 5;          lp.bottomMargin = 5;  //labels 是数据源的个数          for (int i = 0; i < labels.size(); i++) {              View v = View.inflate(context, R.layout.item_flag, null);              TextView tv = (TextView) v.findViewById(R.id.fill_flag);              tv.setText(labels.get(i));              mFlowLayout.addView(v, lp);          }

layout 的   item_flag 中 只有一个TextView