RadioButton监听事件

RadioButton为单选按钮，他须要与RadioGroup配合使用

    对应的布局代码：

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3  xmlns:app="http://schemas.android.com/apk/res-auto"
 4  xmlns:tools="http://schemas.android.com/tools"
 5  android:layout_width="match_parent"
 6  android:layout_height="match_parent"
 7  tools:context=".MainActivity"
 8  android:orientation="vertical">
 9 
10   <TextView 11       android:id="@+id/t1"
12  android:layout_width="match_parent"
13  android:layout_height="wrap_content"
14  android:gravity="center"
15  android:text="input"
16  android:textSize="25sp" />
17   <RadioGroup 18       android:id="@+id/rg"
19  android:layout_width="wrap_content"
20  android:layout_height="wrap_content"
21  android:orientation="vertical">
22     <RadioButton 23         android:id="@+id/rba"
24  android:layout_width="wrap_content"
25  android:layout_height="wrap_content"
26  android:text="A"
27         />
28     <RadioButton 29         android:id="@+id/rbb"
30  android:layout_width="wrap_content"
31  android:layout_height="wrap_content"
32  android:text="B"
33         />
34     <RadioButton 35         android:id="@+id/rbc"
36  android:layout_width="wrap_content"
37  android:layout_height="wrap_content"
38  android:text="C"
39         />
40     <RadioButton 41         android:id="@+id/rbd"
42  android:layout_width="wrap_content"
43  android:layout_height="wrap_content"
44  android:text="D"
45         />
46   </RadioGroup>
47 </LinearLayout>

 

Java代码：

 1 package com.example.administrator.myapplication;  2 
 3 import android.support.v7.app.AppCompatActivity;  4 import android.os.Bundle;  5 import android.view.View;  6 import android.widget.RadioButton;  7 import android.widget.RadioGroup;  8 import android.widget.TextView;  9 import android.widget.Toast; 10 
11 public class MainActivity extends AppCompatActivity { 12  TextView t; 13  @Override 14     protected void onCreate(Bundle savedInstanceState) { 15         super.onCreate(savedInstanceState); 16  setContentView(R.layout.activity_main); 17 
18         t=findViewById(R.id.t1); 19         RadioGroup rg = findViewById(R.id.rg); 20         rg.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() { 21  @Override 22             public void onCheckedChanged(RadioGroup radioGroup, int checkdId) { 23                 RadioButton rb = findViewById(checkdId); 24                 String s = rb.getText().toString(); 25                 t.setText("单击了" +s); 26  } 27  }); 28  } 29 }

在上述代码中，利用setCheckedChangeListener（）监听RadioGroup控件状态，获取监听结果输出到TextView控件里显示