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>