编写程序，利用RadioGroup组件实现性别的单向选择，分别给出MainActivity.java和activity_main.xml中的代码

以下是 MainActivity.java 的代码：

import android.os.Bundle;
import android.widget.RadioGroup;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

    private RadioGroup mRadioGroup;

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

        mRadioGroup = findViewById(R.id.radio_group_gender);

        mRadioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup group, int checkedId) {
                switch (checkedId) {
                    case R.id.radio_button_male:
                        Toast.makeText(MainActivity.this, "您选择了男性", Toast.LENGTH_SHORT).show();
                        break;
                    case R.id.radio_button_female:
                        Toast.makeText(MainActivity.this, "您选择了女性", Toast.LENGTH_SHORT).show();
                        break;
                }
            }
        });
    }
}

以下是 activity_main.xml 的代码：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <RadioGroup
        android:id="@+id/radio_group_gender"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <RadioButton
            android:id="@+id/radio_button_male"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="男性" />

        <RadioButton
            android:id="@+id/radio_button_female"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="女性" />

    </RadioGroup>

</LinearLayout>