Android studio之单选按钮

Android开发单选按钮
创建空activity，
编辑activity_main.xml文件
代码如下：

<?xml version="1.0" encoding="utf-8"?>
<androidx.appcompat.widget.LinearLayoutCompat
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:gravity="center"
    tools:context=".MainActivity">
    <TextView
        android:id="@+id/chooseTxt"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:text="@string/text1"
        android:textColor="@color/colorblack"
        android:textSize="30sp" />
        //定义RaidGroup是要注意属性添加的位置
    <RadioGroup
        android:id="@+id/radioGroup"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:gravity="center"
        >
        <RadioButton
            android:id="@+id/radioButton1"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:button="@null"
            android:drawableRight="@android:drawable/btn_radio"
            android:text="@string/text2"
            />
        <RadioButton
            android:id="@+id/radioButton2"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:text="@string/text3"
            />
    </RadioGroup>

    <Button
        android:id="@+id/ClearBtn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/text4" />
    <Button
        android:id="@+id/AddBtn"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="@string/text5"
         />
</androidx.appcompat.widget.LinearLayoutCompat>

还有strings.xml文件，代码如下：

<resources>
    <string name="app_name">My App</string>
    <string name="text1">我选择的是...?</string>
    <string name="text2">按钮1</string>
    <string name="text3">按钮2</string>
    <string name="text4">清除选中</string>
    <string name="text5">添加子项</string>
</resources>

再是MainActivity.java文件，代码如下：

package com.example.myapp;

import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup.LayoutParams;
import android.widget.Button;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.RadioGroup.OnCheckedChangeListener;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    private RadioGroup  radioGroup;
    private RadioButton radioButton1;
    private RadioButton radioButton2;
    private Button radioClearBtn;
    private Button radioAddBtn;
    private TextView chooseTxt;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        radioButton1 = findViewById(R.id.radioButton1);
        radioButton2 = findViewById(R.id.radioButton2);
        radioGroup= findViewById(R.id.radioGroup);
        //设置选中变换监听
        radioGroup.setOnCheckedChangeListener(onCheckedChangeListener);
        //分别为两个按钮设置点击监听

        radioClearBtn = findViewById(R.id.ClearBtn);
        radioClearBtn.setOnClickListener(onClickListener);

        radioAddBtn = findViewById(R.id.AddBtn);
        radioAddBtn.setOnClickListener(onClickListener);

        chooseTxt = findViewById(R.id.chooseTxt);

    }
    //onCheckedChangeListener()方法
    private  OnCheckedChangeListener onCheckedChangeListener=new OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(RadioGroup group, int checkedId) {
        //定义id并赋值被选中的单选按钮的id
            int id = group.getCheckedRadioButtonId();
            switch (id) {
                case R.id.radioButton1:
                    chooseTxt.setText("我选择的是:" + radioButton1.getText());
                    break;
                case R.id.radioButton2:
                    chooseTxt.setText("我选择的是:" + radioButton2.getText());
                    break;
                default:
                    chooseTxt.setText("我选择的是:新增");
                    break;
             }
        }
    };
    private OnClickListener onClickListener = new OnClickListener() {
        @Override
        public void onClick(View view) {
                switch (view.getId()) {
                    case R.id.ClearBtn:
                        radioGroup.check(-1);//清除选项
                        chooseTxt.setText("我选择的是...?");
                        break;
                    case R.id.AddBtn:
                        RadioButton newRadio = new RadioButton(MainActivity.this);
                        //将新增的radiobutton加入到radioGroup中
                        newRadio.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT));
                        newRadio.setText("新增");
                        radioGroup.addView(newRadio, radioGroup.getChildCount());
                        break;
                    default:
                        break;
                }
        }
    };
}

运行结果如下：