用集合实现RadioButton的添加

第二次更博,离上次一个月了 ，望自己能更加努力学习编程
<?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:id="@+id/activity_main"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context="com.example.administrator.maipaio_0508.MainActivity">    <RadioGroup        android:id="@+id/rG_tiketType"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginStart="30dp"        android:orientation="vertical">        <RadioButton            android:id="@+id/rB_full"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="全票" />        <RadioButton            android:id="@+id/rB_half"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="半票" />        <RadioButton            android:id="@+id/rB_old"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="敬老票" />    </RadioGroup>    <RadioGroup        android:id="@+id/rG_tiketNumber"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_toRightOf="@+id/rG_tiketType"        android:layout_marginStart="90dp">        <RadioButton            android:id="@+id/rB_one"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="1张" />        <RadioButton            android:id="@+id/rB_two"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="2张" />        <RadioButton            android:id="@+id/rB_three"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="3张" />        <RadioButton            android:id="@+id/rB_four"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="4张"/>    </RadioGroup>    <Button        android:id="@+id/button"        android:layout_width="wrap_content"        android:layout_height="wrap_content"       android:layout_below="@+id/rG_tiketNumber"        android:layout_marginTop="100dp"        android:layout_centerHorizontal="true"        android:text="确定"/></RelativeLayout>
java 文档

package com.example.administrator.maipaio_0508;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.CompoundButton;import android.widget.RadioButton;//import android.widget.RadioGroup;import android.widget.Toast;import java.util.ArrayList;public class MainActivity extends AppCompatActivity implements RadioButton.OnCheckedChangeListener {   // private RadioGroup radioGroup;     //两个RadioGroup 懵逼了一好久，还是用集合方便    private RadioButton radioButton;    private Button button;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        button = (Button) findViewById(R.id.button);        int id[] = {R.id.rB_full,                R.id.rB_half,                R.id.rB_old,                R.id.rB_one,                R.id.rB_two,                R.id.rB_four,                R.id.rB_three,        };        for (int i : id) {            radioButton = (RadioButton) findViewById(i);    //            radioButton.setOnCheckedChangeListener(this);   //        }        button.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                show();            }        });    }    public void show() {        String msg = "";        for (CompoundButton chk : selected) {  //遍历集合            msg += chk.getText();        }        if (msg.length() > 0)            msg = "买" + msg;        else            msg = "请买票";        Toast.makeText(this, msg, Toast.LENGTH_SHORT).show();    }        //定义一个ArrayList集合 <  >里面的为泛型  selected为集合名    ArrayList<CompoundButton> selected = new ArrayList<CompoundButton>();    @Override    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {        if (isChecked)            selected.add(buttonView);        else            selected.remove(buttonView);    }}