RadioGroup

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:android="http://schemas.android.com/apk/res/android">
 <RadioGroup
     android:id="@+id/rg_sex"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content">
     <RadioButton
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="男"/>
     <RadioButton
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="女"/>
 </RadioGroup>
</LinearLayout>

package com.example.second;

import android.graphics.Bitmap;
import android.graphics.drawable.Drawable;
import android.os.Bundle;

import com.google.android.material.floatingactionbutton.FloatingActionButton;
import com.google.android.material.snackbar.Snackbar;

import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;

import android.os.Handler;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.ImageView;
import android.widget.RadioGroup;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    private Button btn_icon;
    private Drawable drawable;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        RadioGroup rg=(RadioGroup) findViewById(R.id.rg_sex);
       rg.setOnCheckedChangeListener(new RadioListen());

    }

    private  class RadioListen implements RadioGroup.OnCheckedChangeListener{

        @Override
        public void onCheckedChanged(RadioGroup radioGroup, int i) {
            Toast.makeText(MainActivity.this,"您选中了控件"+i,Toast.LENGTH_LONG).show();
        }
    }





    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }


}