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).set Listener(new View. Listener() {
      @Override
      public void  (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);
      }
    });
  }
}

<?  version=\"1.0\" encoding=\"utf-8\"?>
<LinearLayout  ns:android=\"http://schemas.android.com/apk/res/android\"
   ns:app=\"http://schemas.android.com/apk/res-auto\"
   ns: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.set Listener(new  Listener() {
        @Override
        public void  (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;
        }
      });
    }
  }
}

<?  version=\"1.0\" encoding=\"utf-8\"?>
<LinearLayout  ns: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>

<?  version=\"1.0\" encoding=\"utf-8\"?>
<LinearLayout  ns: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>