Android开发（20）--RadioGroup的使用

RadioGroup 有时候比較实用．主要特征是给用户提供多选一机制。

MainActivity.java

package com.example.lesson16_radio;



import android.app.Activity;

import android.os.Bundle;

import android.widget.RadioButton;

import android.widget.RadioGroup;

import android.widget.Toast;



public class MainActivity extends Activity {

	private RadioGroup group_temo;

	private RadioButton checkRadioButton;



	@Override

	protected void onCreate(Bundle savedInstanceState) {

		super.onCreate(savedInstanceState);

		setContentView(R.layout.activity_main);

		group_temo = (RadioGroup) findViewById(R.id.radioGroup1);

		// 改变默认选项

		group_temo.check(R.id.radio1);



		// 获取默认被被选中值



		checkRadioButton = (RadioButton) group_temo.findViewById(group_temo

				.getCheckedRadioButtonId());



		Toast.makeText(this, "默认的选项的值是:" + checkRadioButton.getText(),

				Toast.LENGTH_LONG).show();



		// 注冊事件

		group_temo

				.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {



					@Override

					public void onCheckedChanged(RadioGroup group, int checkedId) {



						// 点击事件获取的选择对象

						checkRadioButton = (RadioButton) group_temo

								.findViewById(checkedId);



						Toast.makeText(getApplicationContext(),

								"获取的ID是" + checkRadioButton.getText(),

								Toast.LENGTH_LONG).show();

					}

				});

	}



}

布局文件

<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" >



    <RadioGroup

        android:id="@+id/radioGroup1"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_alignParentLeft="true"

        android:layout_alignParentRight="true"

        android:layout_alignParentTop="true" >



        <RadioButton

            android:id="@+id/radio0"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:checked="true"

            android:text="@string/text_java" />



        <RadioButton

            android:id="@+id/radio1"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:text="@string/text_net" />



        <RadioButton

            android:id="@+id/radio2"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:text="@string/text_php" />

    </RadioGroup>



</RelativeLayout>