<?xml version="1.0" encoding="utf-8"?>

<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/rdg"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:orientation="vertical">

        <RadioButton

            android:id="@+id/rbt"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:textSize="25dp"

            android:text="男"

            />

        <RadioButton

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:textSize="25dp"

            android:text="女"

            />

    </RadioGroup>

        <TextView

            android:id="@+id/tv"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:textSize="25dp"

            />

</LinearLayout>

package com.iang.buttonclick;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.widget.RadioGroup;

import android.widget.TextView;

public class MainActivity extends AppCompatActivity  {

    private RadioGroup radioGroup;

    private TextView textView;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

       radioGroup= (RadioGroup)findViewById(R.id.rdg);

        textView=(TextView) findViewById(R.id.tv);

        radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {

            @Override

            public void onCheckedChanged(RadioGroup group, int checkedId) {

                if (checkedId==R.id.rbt)

                    textView.setText("您的性别是:男");

                else

                    textView.setText("您的性别是:女");

            }

        });

    }

}