无涯教程-Android - RadioButton函数

无涯教程
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RadioButton有两种状态:选中或未选中,这允许用户从一组中选择一个选项。

Radio Button

Radio Button

示例

本示例将带您完成一些简单的步骤,以展示如何使用Linear Layout和RadioButton创建自己的Android应用程序。

以下是修改后的主要Activity文件 src/MainActivity.java 的内容。

package com.example.saira_000.myapplication;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.Toast;


public class MainActivity extends ActionBarActivity {
RadioGroup rg1;
RadioButton rb1;
Button b1;


protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
addListenerRadioButton();
}


private void addListenerRadioButton() {
rg1 = (RadioGroup) findViewById(R.id.radioGroup);
b1 = (Button) findViewById(R.id.button2);
b1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
int selected=rg1.getCheckedRadioButtonId();
rb1=(RadioButton)findViewById(selected);
Toast.makeText(MainActivity.this,rb1.getText(),Toast.LENGTH_LONG).show();
}
});
}
}

以下是 res/layout/activity_main.xml 文件的内容-

<?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: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=".MainActivity">

<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Example of Radio Button"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:textSize="30dp" />


<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Tutorials point"
android:textColor="#ff87ff09"
android:textSize="30dp"
android:layout_above="@+id/imageButton"
android:layout_centerHorizontal="true"
android:layout_marginBottom="40dp" />


<ImageButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageButton"
android:src="@drawable/abc"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true" />


<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/button2"
android:text="ClickMe"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true" />


<RadioGroup
android:id="@+id/radioGroup"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_below="@+id/imageButton"
android:layout_alignLeft="@+id/textView2"
android:layout_alignStart="@+id/textView2">


  </span><span class="tag">&lt;RadioButton</span><span class="pln">
     </span><span class="atn">android:layout_width</span><span class="pun">=</span><span class="atv">"142dp"</span><span class="pln">
     </span><span class="atn">android:layout_height</span><span class="pun">=</span><span class="atv">"wrap_content"</span><span class="pln">
     </span><span class="atn">android:text</span><span class="pun">=</span><span class="atv">"JAVA"</span><span class="pln">
     </span><span class="atn">android:id</span><span class="pun">=</span><span class="atv">"@+id/radioButton"</span><span class="pln">
     </span><span class="atn">android:textSize</span><span class="pun">=</span><span class="atv">"25dp"</span><span class="pln">
     </span><span class="atn">android:textColor</span><span class="pun">=</span><span class="atv">"@android:color/holo_red_light"</span><span class="pln">
     </span><span class="atn">android:checked</span><span class="pun">=</span><span class="atv">"false"</span><span class="pln">
     </span><span class="atn">android:layout_gravity</span><span class="pun">=</span><span class="atv">"center_horizontal"</span><span class="pln"> </span><span class="tag">/&gt;</span><span class="pln">
     
  </span><span class="tag">&lt;RadioButton</span><span class="pln">
     </span><span class="atn">android:layout_width</span><span class="pun">=</span><span class="atv">"wrap_content"</span><span class="pln">
     </span><span class="atn">android:layout_height</span><span class="pun">=</span><span class="atv">"wrap_content"</span><span class="pln">
     </span><span class="atn">android:text</span><span class="pun">=</span><span class="atv">"ANDROID"</span><span class="pln">
     </span><span class="atn">android:id</span><span class="pun">=</span><span class="atv">"@+id/radioButton2"</span><span class="pln">
     </span><span class="atn">android:layout_gravity</span><span class="pun">=</span><span class="atv">"center_horizontal"</span><span class="pln">
     </span><span class="atn">android:checked</span><span class="pun">=</span><span class="atv">"false"</span><span class="pln">
     </span><span class="atn">android:textColor</span><span class="pun">=</span><span class="atv">"@android:color/holo_red_dark"</span><span class="pln">
     </span><span class="atn">android:textSize</span><span class="pun">=</span><span class="atv">"25dp"</span><span class="pln"> </span><span class="tag">/&gt;</span><span class="pln">
     
  </span><span class="tag">&lt;RadioButton</span><span class="pln">
     </span><span class="atn">android:layout_width</span><span class="pun">=</span><span class="atv">"136dp"</span><span class="pln">
     </span><span class="atn">android:layout_height</span><span class="pun">=</span><span class="atv">"wrap_content"</span><span class="pln">
     </span><span class="atn">android:text</span><span class="pun">=</span><span class="atv">"HTML"</span><span class="pln">
     </span><span class="atn">android:id</span><span class="pun">=</span><span class="atv">"@+id/radioButton3"</span><span class="pln">
     </span><span class="atn">android:layout_gravity</span><span class="pun">=</span><span class="atv">"center_horizontal"</span><span class="pln">
     </span><span class="atn">android:checked</span><span class="pun">=</span><span class="atv">"false"</span><span class="pln">
     </span><span class="atn">android:textSize</span><span class="pun">=</span><span class="atv">"25dp"</span><span class="pln">
     </span><span class="atn">android:textColor</span><span class="pun">=</span><span class="atv">"@android:color/holo_red_dark"</span><span class="pln"> </span><span class="tag">/&gt;</span><span class="pln">
     



</RadioGroup>


</RelativeLayout>

以下是 res/values/strings.xml 的内容,以定义这些新常量-

<?xml version="1.0" encoding="utf-8"?>
<resources>
   <string name="app_name">My Application</string>
</resources>

以下是 AndroidManifest.xml 的默认内容-

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
   package="com.example.saira_000.myapplication" >

<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >


  </span><span class="tag">&lt;activity</span><span class="pln">
     </span><span class="atn">android:name</span><span class="pun">=</span><span class="atv">"com.example.My Application.MainActivity"</span><span class="pln">
     </span><span class="atn">android:label</span><span class="pun">=</span><span class="atv">"@string/app_name"</span><span class="pln"> </span><span class="tag">&gt;</span><span class="pln">
  
     </span><span class="tag">&lt;intent-filter&gt;</span><span class="pln">
        </span><span class="tag">&lt;action</span><span class="pln"> </span><span class="atn">android:name</span><span class="pun">=</span><span class="atv">"android.intent.action.MAIN"</span><span class="pln"> </span><span class="tag">/&gt;</span><span class="pln">
        </span><span class="tag">&lt;category</span><span class="pln"> </span><span class="atn">android:name</span><span class="pun">=</span><span class="atv">"android.intent.category.LAUNCHER"</span><span class="pln"> </span><span class="tag">/&gt;</span><span class="pln">
     </span><span class="tag">&lt;/intent-filter&gt;</span><span class="pln">

  </span><span class="tag">&lt;/activity&gt;</span><span class="pln">
  



</application>
</manifest>

单击运行 Eclipse Run Icon工具栏。 Android Studio将应用程序安装在您的AVD上并启动它,如果您的设置和应用程序一切正常,它将显示在"Emulator"窗口下面-

Android RadioButton Control

如果用户选择了任何一个单选按钮,则它应该在Toast消息中使用相同的名称。例如,如果用户选择了JAVA,它将给出一个消息,即JAVA

参考链接

www.learnfk.com/android/and…

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