Android自定View流式布局根据文字数量换行

package com.example.customwaterfallviewgroup;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;

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

public class MainActivity extends AppCompatActivity {
  List<String  stringList = new ArrayList< ();
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    initView();
  }

  private void initView() {
    final EditText editText = findViewById(R.id.edit);
    final CustomWaterFallViewGroup customWaterFallViewGroup = findViewById(R.id.water_fill);
    findViewById(R.id.button).setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        //获取输入框的值
        String str = editText.getText().toString();
        //将文字放入列表
        stringList.add(str);
        //设置数据
        customWaterFallViewGroup.setData(stringList);
      }
    });
  }
}

<?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="wrap_content"
  android:orientation="vertical"
  tools:context=".MainActivity" 

  <EditText
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/edit"
    android:hint="输入"
    / 
  <Button
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/button"
    android:text="add"
    / 
  <com.example.customwaterfallviewgroup.CustomWaterFallViewGroup
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/water_fill"
    / 
</LinearLayout 

package com.example.customwaterfallviewgroup;
import android.content.Context;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
public class CustomWaterFallViewGroup extends LinearLayout {
//设置每一行最大的字符串的长度
int mMaxSize = 22;
//传入的字符串数组
List<String  stringList = new ArrayList< ();
Context mcontext;
public CustomWaterFallViewGroup(Context context) {
super(context);
mcontext = context;
init();
}
public CustomWaterFallViewGroup(Context context,AttributeSet attrs) {
super(context, attrs);
mcontext = context;
init();
}
//定义布局
private void init() {
//设置最外层的LinearLayout 为垂直布局
setOrientation(VERTICAL);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
DisplayMetrics displayMetrics = mcontext.getResources().getDisplayMetrics();
int widthPixels = displayMetrics.widthPixels;
setMeasuredDimension(widthPixels,heightMeasureSpec);
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
super.onLayout(changed, l, t, r, b);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
}
public void setData(List<String  stringList) {
//上一个输入框里的数据存到这个页面的集合中 
this.stringList = stringList;
showData();
}
private void showData() {
//因为每一次都要重新画 ，所以移除之前的布局 显示更新过的布局
removeAllViews();
//优先向跟布局添加一条横向布局
LinearLayout linearLayout_h = (LinearLayout) View.inflate(mcontext,R.layout.item_water_fall_h,null);
addView(linearLayout_h);
//定义临时变量。用来计算最后一行已有的字符长度
int len = 0;
for (int i = 0;i<stringList.size();i++){
String str = stringList.get(i);
//将次字符串长度与记录的已有字符串长度相加
len += str.length();
//-判断 如果大于最大长度，说明这一行放不下了
//需要自动换行
if (len   mMaxSize){
//像跟布局添加一条横布局
linearLayout_h = (LinearLayout) View.inflate(mcontext,R.layout.item_water_fall_h,null);
addView(linearLayout_h);
//换行以后因为不添加了 所以 当前的救是最后一行的长度
len = str.length();
}
//添加一个textView控件
View view = View.inflate(mcontext,R.layout.water_fall_textview,null);
//获取到它的ID
TextView textView = view.findViewById(R.id.water_fall_textview);
//得到后给它赋值 （输入框里的值 给它）
textView.setText(str);
//添加到布局中
linearLayout_h.addView(view);
//设置权重 让每一行内所有的控件相加充满整行，并合理分配
LinearLayout.LayoutParams layoutParams = (LinearLayout.LayoutParams) view.getLayoutParams();
layoutParams.weight = 1;
view.setLayoutParams(layoutParams);
final int index = i;
view.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(mcontext,"您点击了"+stringList.get(index),Toast.LENGTH_SHORT).show();
}
});
view.setOnLongClickListener(new OnLongClickListener() {
@Override
public boolean onLongClick(View v) {
stringList.remove(index);
showData();
return false;
}
});
}
}
}

<?xml version="1.0" encoding="utf-8"? 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/water_fall_h"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" 
</LinearLayout 

<?xml version="1.0" encoding="utf-8"? 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
<TextView
android:id="@+id/water_fall_textview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@color/colorAccent"
android:layout_weight="1"
android:textSize="20dp"
android:layout_marginRight="5dp"
android:layout_marginLeft="5dp"
android:layout_marginTop="10dp"
android:gravity="center"
/ 
</LinearLayout