android studio RadioButton单选按钮

1.定义
<!--单选按钮-->
<TextViewandroid:layout_marginTop="10dp"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="请选择你的性别：">
</TextView>
<RadioGroupandroid:id="@+id/rg_gender"android:layout_width="match_parent"android:layout_height="wrap_content"android:orientation="horizontal"android:layout_marginTop="5dp"><RadioButtonandroid:id="@+id/rb_male"android:layout_width="0dp"android:layout_weight="1"android:layout_height="wrap_content"android:text="男"></RadioButton><RadioButtonandroid:id="@+id/rb_female"android:layout_width="0dp"android:layout_weight="1"android:layout_height="wrap_content"android:text="女"></RadioButton></RadioGroup><TextViewandroid:id="@+id/tv6"android:layout_marginTop="10dp"android:layout_width="match_parent"android:layout_height="wrap_content">
</TextView>

2.代码

RadioButton rb1 = findViewById(R.id.rb_male);
RadioButton rb2 = findViewById(R.id.rb_female);
RadioGroup rg = findViewById(R.id.rg_gender);
tv6 = findViewById(R.id.tv6);
rg.setOnCheckedChangeListener(this::onCheckedChange);

private void onCheckedChange(RadioGroup radioGroup, int i) {switch (i) {case R.id.rb_male:tv6.setText("男");break;case R.id.rb_female:tv6.setText("女");break;}}