RadioGroup初识

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_radio_button"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.axnet.buju0711.RadioButtonActivity">
    <!--checked默认选择-->
    <RadioGroup
        android:id="@+id/rg1"
        android:layout_height="wrap_content"
        android:layout_width="match_parent"
        android:orientation="horizontal"
        >
        <RadioButton
            android:id="@+id/man"
            android:layout_height="wrap_content"
            android:layout_width="wrap_content"
            android:text="男"
            android:layout_weight="1"
            android:checked="true"
            />
        <RadioButton
            android:id="@+id/woman"
            android:layout_height="wrap_content"
            android:layout_width="wrap_content"
            android:layout_weight="1"
            android:text="女"
            />
    </RadioGroup>
    <TextView
      style="@style/wr"
      android:id="@+id/tv1"
      android:text="text"
      android:textSize="28sp"
        />
</LinearLayout>

public class RadioButtonActivity extends AppCompatActivity {
    private RadioGroup rg1;
    private TextView tv1;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_radio_button);
        init();
        rg1.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup group, int checkedId) {
                switch (checkedId){
                    case R.id.woman:
                        tv1.setText("women");
                        break;
                    case R.id.man:
                        tv1.setText("man");
                    default:
                        break;
                }
            }
        });
    }

    private void init() {
        rg1=(RadioGroup)findViewById(R.id.rg1);
        tv1=(TextView)findViewById(R.id.tv1);
    }
}