Android開發（20）--RadioGroup的使用

RadioGroup 有時候比較有用．主要特徵是給用戶提供多選一機制。

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);
		// 改變默認選項
		group_temo.check(R.id.radio1);

		// 獲取默認被被選中值

		checkRadioButton = (RadioButton) group_temo.findViewById(group_temo
				.getCheckedRadioButtonId());

		Toast.makeText(this, "默認的選項的值是:" + checkRadioButton.getText(),
				Toast.LENGTH_LONG).show();

		// 註冊事件
		group_temo
				.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {

					@Override
					public void onCheckedChanged(RadioGroup group, int checkedId) {

						// 點擊事件獲取的選擇對象
						checkRadioButton = (RadioButton) group_temo
								.findViewById(checkedId);

						Toast.makeText(getApplicationContext(),
								"獲取的ID是" + checkRadioButton.getText(),
								Toast.LENGTH_LONG).show();
					}
				});
	}

}

佈局文件

<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>