单选按钮（RadioButton）

//单选按钮
public class RadioButtonActivity extends Activity {

    private Context context;
    private RadioGroup sexRadioGroup;
    private RadioButton maleRadioButton;
    private RadioButton femaleRadioButton;
    private RadioButton sexRadioButton;
    private Button submitButton;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.radio_button);

        init();
        addAction();

    }

    private void init() {
        context = this;
        sexRadioGroup = (RadioGroup) findViewById(R.id.sexRadioGroupId);
        maleRadioButton = (RadioButton) findViewById(R.id.maleRadioButtonId);
        femaleRadioButton = (RadioButton) findViewById(R.id.femaleRadioButtonId);
        sexRadioButton = (RadioButton) findViewById(R.id.sexRadioButtonId);
        submitButton = (Button) findViewById(R.id.submitButtonId);
    }

    private void addAction() {
        // sexRadioGroup.setOnClickListener(l),setOnClickListener:点击的时候触发
        // setOnCheckedChangeListener:状态改变的时候触发
        // 两者都能实现对CheckBox的状态改变的监听，但一般情况下，用的更多的是setOnCheckedChangeListener。
        //因为，当CheckBox的状态不是通过点击事件改变，而是通过其他的方式改变时，比如setCheck()，setOnClickListener无法完成此种情况下的监听。
        //OnCheckChangedListener监听CheckBox的状态，无论来自你的onClick事件还是其他。
        sexRadioGroup
                .setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
                    public void onCheckedChanged(RadioGroup group, int checkedId) {
                        switch (checkedId) {
                        case R.id.maleRadioButtonId:
                            Toast.makeText(context, "你选择了\"男\".",
                                    Toast.LENGTH_SHORT).show();
                            break;
                        case R.id.femaleRadioButtonId:
                            Toast.makeText(context, "你选择了\"女\".",
                                    Toast.LENGTH_SHORT).show();
                            break;
                        case R.id.sexRadioButtonId:
                            Toast.makeText(context, "你选择了\"人妖\".",
                                    Toast.LENGTH_SHORT).show();
                            break;
                        default:
                            break;
                        }
                    }
                });

        submitButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                String sex = null;
                if (maleRadioButton.isChecked()) {
                    sex = "男";
                }
                if (femaleRadioButton.isChecked()) {
                    sex = "女";
                }
                if (sexRadioButton.isChecked()) {
                    sex = "人妖";
                }
                Toast.makeText(context, "你的性别是:" + sex, Toast.LENGTH_SHORT)
                        .show();
            }
        });
    }

}

<?xml version="1.0" encoding="utf-8"?>
<!-- 单选按钮页面 -->
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="5dp" >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="性别:"
            android:textSize="20sp" />

        <RadioGroup
            android:id="@+id/sexRadioGroupId"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal" >
<!--        android:button="@null" 可以自定义图片-->
            <RadioButton
                android:id="@+id/maleRadioButtonId"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:checked="true"
                android:text="男" />

            <RadioButton
                android:id="@+id/femaleRadioButtonId"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="女" />
            
            <RadioButton
                android:id="@+id/sexRadioButtonId"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="人妖" />
        </RadioGroup>
    </LinearLayout>

    <Button
        android:id="@+id/submitButtonId"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="right"
        android:text="确定"
        android:textSize="20sp" />

</LinearLayout>