RadioButton就是常用到的單選按鈕，一般常用到RadioGroup，一個RadioGroup里面可以有多個RadioButton，這里面的單選按鈕一次只能選一個，比如常見的性別的選項，只能選擇male或者female。一個Activity里面當然也可以有多個RadioGroup，不同的RadioGroup互相不影響，這里就簡單的測試了如下圖：

功能也很簡單，這里面放置了兩個RadioGroup，每個組里面有兩個RadioButton，在代碼上就簡單的寫了下測試函數。設置對應兩個RadioButton的CheckedChange監聽事件， 然后在方法體里面添加同步顯示，方法很簡單，比如選中了“男”就把對應的“A”選中，選中了“女”就把對應的“B”給選中，那么反過來也是同樣的。貼上代碼：

package com.example.urien.secondapp;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.CompoundButton;
import android.widget.RadioButton;
import android.widget.RadioGroup;

public class Lesson5_Activity extends AppCompatActivity {

    //1.聲明控件
    private RadioGroup L5_radioGroup;
    private RadioButton L5_radioButtonFemale;
    private RadioButton L5_radioButtonMale;

    private RadioGroup L5_radioGroup2;
    private RadioButton L5_radioButtonA;
    private RadioButton L5_radioButtonB;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_lesson5_);

        //2.找到控件
        L5_radioGroup = findViewById(R.id.L5_radioGroup);
        L5_radioButtonFemale = findViewById(R.id.L5_radio_female);
        L5_radioButtonMale = findViewById(R.id.L5_radio_male);

        L5_radioGroup2 = findViewById(R.id.L5_radioGroup2);
        L5_radioButtonA = findViewById(R.id.L5_radio_A);
        L5_radioButtonB = findViewById(R.id.L5_radio_B);

        //4.設置監聽器
        L5_radioGroup.setOnCheckedChangeListener(new radioGroupListener());
        L5_radioGroup2.setOnCheckedChangeListener(new radioGroupListener());

        L5_radioButtonMale.setOnCheckedChangeListener(new radioButtonListener());
    }


    //3.實現監聽器接口方法
    class radioButtonListener implements CompoundButton.OnCheckedChangeListener{

        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            System.out.println("male is selected ————>" + isChecked);
        }
    }
    class radioGroupListener implements RadioGroup.OnCheckedChangeListener{

        @Override
        public void onCheckedChanged(RadioGroup group, int checkedId) {
            if(group.getId() == L5_radioGroup.getId()){
                if(checkedId == R.id.L5_radio_male){
                    System.out.println("選中了male");
                    L5_radioButtonA.setChecked(true);
                }
                else if(checkedId == R.id.L5_radio_female){
                    System.out.println("選中了female");
                    L5_radioButtonB.setChecked(true);
                }
            }
            else if(group.getId() == L5_radioGroup2.getId()){
                if(checkedId == L5_radioButtonA.getId()){
                    System.out.println("選中了A");
                    L5_radioButtonMale.setChecked(true);
                }
                else if(checkedId == L5_radioButtonB.getId()){
                    System.out.println("選中了B");
                    L5_radioButtonFemale.setChecked(true);
                }
            }
        }
    }
}

By Urien 2018年5月12日 21:50:47