自定义View流式布局

FlowLayout：

package com.example.a03_flowlayout.flowlayout;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 yujie on 2017/12/1. */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);        // TODO Auto-generated constructor stub    }    public FlowLayout(Context context, AttributeSet attrs) {        this(context, attrs, 0);        // TODO Auto-generated constructor stub    }    public FlowLayout(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);        // TODO Auto-generated constructor stub    }    @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) {        // TODO Auto-generated method stub        return new MarginLayoutParams(getContext(), attrs);    }
}
代码中使用：
package com.example.a03_flowlayout;import android.graphics.Color;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.ViewGroup;import android.widget.TextView;import com.example.a03_flowlayout.flowlayout.FlowLayout;public class MainActivity extends AppCompatActivity {    private String mNames[] = {            "welcome","android","TextView",            "apple","jamy","kobe bryant",            "jordan","layout","viewgroup",            "margin","padding","text",            "name","type","search","logcat"    };    private FlowLayout flowLayout;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initChildViews();    }    private void initChildViews() {        // TODO Auto-generated method stub        flowLayout = findViewById(R.id.flow_layout);        ViewGroup.MarginLayoutParams lp = new ViewGroup.MarginLayoutParams(                ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);        lp.leftMargin = 5;        lp.rightMargin = 5;        lp.topMargin = 5;        lp.bottomMargin = 5;        for(int i = 0; i < mNames.length; i ++){            TextView view = new TextView(this);            view.setText(mNames[i]);            view.setTextColor(Color.WHITE);            view.setBackgroundDrawable(getResources().getDrawable(R.drawable.textview_bg));            flowLayout.addView(view,lp);        }    }}
布局：
<?xml version="1.0" encoding="utf-8"?><LinearLayout    xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="com.example.a03_flowlayout.MainActivity">    <com.example.a03_flowlayout.flowlayout.FlowLayout        android:id="@+id/flow_layout"        android:layout_width="200dp"        android:layout_height="wrap_content">    </com.example.a03_flowlayout.flowlayout.FlowLayout></LinearLayout>

textview_bg:

<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android">    <solid android:color="#666666" />    <corners android:radius="10dp" />    <padding        android:left="5dp"        android:right="5dp"        android:top="5dp"        android:bottom="5dp"        /></shape>