单项选择(RadioGroup)
RadioGroup 是 LinearLayout 的子类,继承关系例如以下:
android.view.ViewGroup
android.widget.LinearLayout
android.widget.RadioGroup
RadioGroup 类方法
RadioGroup 演示样例
完整project:http://download.csdn.net/detail/sweetloveft/9402088
下述程序中,主要学习 RadioGroup 的使用方法,须要注意单选button的处理逻辑是通过监听 RadioGroup 完毕的,详细处理哪个单选button则是通过 getId() 完毕的。
1.MainActivity.java
package com.sweetlover.activity; import com.sweetlover.radiogroupdemo.R; import android.app.Activity; import android.os.Bundle; import android.widget.RadioButton; import android.widget.RadioGroup; import android.widget.Toast; import android.widget.RadioGroup.OnCheckedChangeListener; import android.widget.TextView; public class MainActivity extends Activity { private static final int BTN_NUM = 6; private TextView textView = null; private RadioGroup radioGroup = null; private RadioButton[] radioButton = null; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); radioButton = new RadioButton[BTN_NUM]; textView = (TextView)findViewById(R.id.textView1); radioGroup = (RadioGroup)findViewById(R.id.radioGroup); radioButton[0] = (RadioButton)findViewById(R.id.radioButton1); radioButton[1] = (RadioButton)findViewById(R.id.radioButton2); radioButton[2] = (RadioButton)findViewById(R.id.radioButton3); radioButton[3] = (RadioButton)findViewById(R.id.radioButton4); radioButton[4] = (RadioButton)findViewById(R.id.radioButton5); radioButton[5] = (RadioButton)findViewById(R.id.radioButton6); radioGroup.setOnCheckedChangeListener(new RadioGroupCheckedListener()); } class RadioGroupCheckedListener implements OnCheckedChangeListener { @Override public void onCheckedChanged(RadioGroup group, int checkedId) { // TODO Auto-generated method stub for (int i = 0; i < BTN_NUM; i++) { if (checkedId == radioButton[i].getId() && radioButton[i].isChecked()) { CharSequence text = radioButton[i].getText(); textView.setText(text); Toast.makeText(MainActivity.this, text, Toast.LENGTH_SHORT).show(); break; } } } } }
2.activity_main.xml
<?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="match_parent" android:padding="30dp" android:orientation="vertical" > <TextView android:id="@+id/textView1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center" android:text="@string/system" android:textAppearance="?
android:attr/textAppearanceMedium" /> <RadioGroup android:id="@+id/radioGroup" android:layout_width="match_parent" android:layout_height="wrap_content" android:padding="30dp" > <RadioButton android:id="@+id/radioButton1" android:layout_width="160dp" android:layout_height="wrap_content" android:layout_gravity="center" android:text="@string/os1" /> <RadioButton android:id="@+id/radioButton2" android:layout_width="160dp" android:layout_height="wrap_content" android:layout_gravity="center" android:text="@string/os2" /> <RadioButton android:id="@+id/radioButton3" android:layout_width="160dp" android:layout_height="wrap_content" android:layout_gravity="center" android:text="@string/os3" /> <RadioButton android:id="@+id/radioButton4" android:layout_width="160dp" android:layout_height="wrap_content" android:layout_gravity="center" android:text="@string/os4" /> <RadioButton android:id="@+id/radioButton5" android:layout_width="160dp" android:layout_height="wrap_content" android:layout_gravity="center" android:text="@string/os5" /> <RadioButton android:id="@+id/radioButton6" android:layout_width="160dp" android:layout_height="wrap_content" android:layout_gravity="center" android:text="@string/os6" /> </RadioGroup> </LinearLayout>
3.string.xml
<resources> <string name="app_name">RadioGroupDemo</string> <string name="system">操作系统</string> <string name="os1">Android</string> <string name="os2">Sysbian</string> <string name="os3">WinCE</string> <string name="os4">PalmOS</string> <string name="os5">Linux</string> <string name="os6">iPhoneOS</string> </resources>
4.AndroidManifest.xml
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.sweetlover.radiogroupdemo" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="8" android:targetSdkVersion="19" /> <application android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name="com.sweetlover.activity.MainActivity"> <intent-filter> <action android:name="android.intent.action.MAIN"/> <category android:name="android.intent.category.LAUNCHER"/> </intent-filter> </activity> </application> </manifest>