28 自定义View流式布局

流式布局每行的行高以本行中最高的元素作为高,如果一个元素放不下到一行时直接到第二行
这里写图片描述
这里写图片描述

FlowLayoutView

package com.qf.sxy.customview05.widget;

import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;

import java.util.ArrayList;
import java.util.List;

/**
 * Created by sxy on 2016/9/29.
 * 流式布局   标签
 */
public class FlowLayoutView extends ViewGroup{
    public FlowLayoutView(Context context) {
        super(context);
    }

    public FlowLayoutView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

      //或ViewGroup中所有子元素的属性
    //否则只获取ViewGroup 的属性
    @Override
    public LayoutParams generateLayoutParams(AttributeSet attrs) {
        return new MarginLayoutParams(getContext(),attrs);
    }


    /**
     * 测量控件本身的大小   宽和高   根据子内容获取
     * @param widthMeasureSpec
     * @param heightMeasureSpec
     */
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        //获取父布局的模式和尺寸
        int sizeWidth  = MeasureSpec.getSize(widthMeasureSpec);
        int modeWidth = MeasureSpec.getMode(widthMeasureSpec);
        int sizeHeight = MeasureSpec.getSize(heightMeasureSpec);
        int modeHeight = MeasureSpec.getMode(heightMeasureSpec);

        //记录Wrap_content的宽高
        int width = 0;
        int height = 0;

        //没一行的宽和高
        int lineWidth = 0;
        int lineHeight =0;

        //获取子元素的数量
        int cCount = getChildCount();
        //进行遍历子元素
        for(int i=0;i<cCount;i++){
            //获取每一个子元素
            View child = getChildAt(i);
            //测量每一个子元素内部的子元素的长宽高
            //否则child.getMeasuredWidth()为0
            measureChild(child,widthMeasureSpec,heightMeasureSpec);
            //获取每个子元素的属性
            MarginLayoutParams layoutParams = (MarginLayoutParams) child.getLayoutParams();

            //获取当前子元素的宽和高
            int childWidth = child.getMeasuredWidth()+layoutParams.leftMargin+layoutParams.rightMargin;
            int childHeight = child.getMeasuredHeight()+layoutParams.bottomMargin+layoutParams.topMargin;


                       if(lineWidth+childWidth>getWidth()-getPaddingLeft()-getPaddingRight()){//换行
                width = Math.max(lineWidth,childWidth);
                lineWidth = childWidth;//重新开一行  当前行的宽度
                //叠加之前的高度
                height += lineHeight;
                //重新开一行  这个新行的高度
                lineHeight = childHeight;
            }else{//不换行
                //记录当前行的宽
                lineWidth += childWidth;
                //记录一行中的高度
                lineHeight = Math.max(lineHeight,childHeight);
            }

            if(i ==cCount-1){//判断是否是最后一个元素
                width = Math.max(width,lineWidth);
                height += lineHeight;
            }
            //设置ViewGrop最终宽高
            setMeasuredDimension(modeWidth==MeasureSpec.EXACTLY?sizeWidth:width+getPaddingRight()+getPaddingLeft(),
                                modeHeight==MeasureSpec.EXACTLY?sizeHeight:height+getPaddingBottom()+getPaddingTop());
        }

    }

    //记录所有子元素   按行存取
    List<List<View>> mAllViews = new ArrayList<>();
    //记录每一行中最大的高度
    private List<Integer> mLineHeight = new ArrayList<>();

    //摆放子View ???????????????
    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        //为了多次执行时  数据正确
        mAllViews.clear();
        mLineHeight.clear();

        //获取父控件的宽度
        int width = getWidth();

        //记录一行中的宽和高
        int lineWidth = 0;
        int lineHeight = 0;

        //记录一行中的 View
        List<View> lineView = new ArrayList<>();

        //获取子元素的个数
        int cCount = getChildCount();
        Log.e("AAA","==AAAA=>"+cCount);
        //遍历所有子元素
        for(int i=0;i<cCount;i++){

            View child = getChildAt(i);
            //获取每个子元素的属性
            MarginLayoutParams layoutParams = (MarginLayoutParams) child.getLayoutParams();

            //获取当前子元素的宽和高
            int childWidth = child.getMeasuredWidth()+layoutParams.leftMargin+layoutParams.rightMargin;
            int childHeight = child.getMeasuredHeight()+layoutParams.bottomMargin+layoutParams.topMargin;

            if(lineWidth+childWidth>width-getPaddingLeft()-getPaddingRight()){//判断是否换行
                //记录一行的高 和一行中的View
                mLineHeight.add(lineHeight);
                mAllViews.add(lineView);

                Log.e("AAA","==>VVV===>"+mAllViews.size());
                //让数据重置
                lineWidth = 0;
                lineView = new ArrayList<>();
                 if (i == cCount - 1) {
                    lineView.add(child);
                }
            }else{
                //记录一行中的宽  高  view
                lineWidth += childWidth;
                lineHeight = Math.max(lineHeight,childHeight);
                lineView.add(child);
            }



        }
//处理元素   数据以每行的形式处理
        mLineHeight.add(lineHeight);
        mAllViews.add(lineView);


        //获取每个View的padding
        int left = getPaddingLeft();
        int top = getPaddingTop();
        //获取有多少行
        int lineNum = mAllViews.size();
        Log.e("AAA","=BBB=>"+lineNum);
        //展示每一行
        for(int i=0;i<lineNum;i++){
            lineHeight = mLineHeight.get(i);
            lineView   = mAllViews.get(i);
            //遍历每一行
            // 取出 每一行的 所有的View
            lineView = mAllViews.get(i);
            lineHeight = mLineHeight.get(i);
            // 循环遍历  每一行的View
            for(int j=0;j<lineView.size();j++){
                View child = lineView.get(j);
                MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams();

                int lc = left+lp.leftMargin;
                int tc = top+lp.topMargin;
                int rc = lc+child.getMeasuredWidth();
                int bc = tc+child.getMeasuredHeight();
                //摆放 子View的位置
                child.layout(lc, tc, rc, bc);
                //叠加   前一个View 的 实际宽度
                left += child.getMeasuredWidth()+lp.leftMargin+lp.rightMargin;
            }
            //换行了 重置
            left = getPaddingLeft();
            top+=lineHeight;

        }
    }
}

MainActivity

package com.qf.sxy.customview05;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.LayoutInflater;
import android.widget.TextView;

import com.qf.sxy.customview05.widget.FlowLayoutView;

public class MainActivity extends AppCompatActivity {

    private FlowLayoutView flowLayoutView;

    private String[]titils = {"sds","da","aa","fff","gggggg","hhgghg","jjhhhh","aa","fff","gggggg","hhgghg","jjhhhh","sds","da","aa","fff","gggggg","sds","da","aa","fff","gggggg"};

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        flowLayoutView = ((FlowLayoutView) findViewById(R.id.flowLayoutView));

        //5.fori
        for (int i = 0; i < titils.length; i++) {
//            Button btn = new Button(MainActivity.this);
//            btn.setText(titils[i]);
//            //设置Button属性 内容包裹
//            ViewGroup.MarginLayoutParams p= new ViewGroup.MarginLayoutParams(ViewGroup.MarginLayoutParams.WRAP_CONTENT,ViewGroup.MarginLayoutParams.WRAP_CONTENT);
//            flowLayoutView.addView(btn,p);
            TextView tv = (TextView) LayoutInflater.from(MainActivity.this).inflate(R.layout.tv,flowLayoutView,false);
            tv.setText(titils[i]);
            flowLayoutView.addView(tv);
        }
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"

    tools:context="com.qf.sxy.customview05.MainActivity">

    <com.qf.sxy.customview05.widget.FlowLayoutView
        android:id="@+id/flowLayoutView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#444444"
         >

    </com.qf.sxy.customview05.widget.FlowLayoutView>
</RelativeLayout>

tv.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="AAA"
    android:textColor="#ff0000"
    android:background="@drawable/tv_shape"
    >

</TextView>

tv_shape.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">

    <corners android:radius="30dp"></corners>
    <solid android:color="#ffffff"></solid>
    <padding
        android:left="10dp"
        android:right="10dp"
        android:top="10dp"
        android:bottom="10dp"
        ></padding>

</shape>
原文地址:https://www.cnblogs.com/muyuge/p/6152162.html