一个activity是用来做题用的，效果如下图
在点击下一题时，RadioGroup会默认为第一次选中的状态，造成RadioButton选择混。
解决方案： 第一步：取消监听 radioGroup_problem_group.setOnCheckedChangeListener(null); radioGroup_problem_group为RadioGroup变量名。
第二部：清除选中记录 radioGroup_problem_group.clearCheck();
主要代码：
1. 布局文件：
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent"> <!--单选题--> <LinearLayout android:id="@+id/linearLayout_problem" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="20dp" android:layout_marginLeft="20dp" android:layout_marginRight="20dp" android:visibility="visible" > <!--题目标题--> <LinearLayout android:id="@+id/linearLayout_problem_problem" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_alignParentTop="true" > <!--选择题目题号--> <TextView android:id="@+id/textView_problem_number" android:layout_width="wrap_content" android:layout_height="wrap_content" /> <!--选择题目标题--> <TextView android:id="@+id/textView_problem_title" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginLeft="10dp" /> </LinearLayout> <!--题目选项--> <LinearLayout android:id="@+id/linearLayout_problem_checkBox" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="20dp" android:layout_marginLeft="5dp" > <!--选项单选--> <RadioGroup android:id="@+id/radioGroup_problem_group" android:layout_width="match_parent" android:layout_height="wrap_content" > <!--题目选项1 android:background="@drawable/linear_layout_middle_content" --> <RadioButton android:id="@+id/radioButton_problem_option1" android:layout_width="match_parent" android:layout_height="wrap_content" /> <!--题目选项2--> <RadioButton android:id="@+id/radioButton_problem_option2" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="20dp" /> <!--题目选项3--> <RadioButton android:id="@+id/radioButton_problem_option3" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="20dp" /> <!--题目选项4--> <RadioButton android:id="@+id/radioButton_problem_option4" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="20dp" /> </RadioGroup> </LinearLayout> </LinearLayout> <!--显示已答和总题数信息--> <LinearLayout android:id="@+id/linearLayout_problem_information" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="20dp" android:layout_marginLeft="20dp" android:layout_marginRight="20dp" android:visibility="visible" > <LinearLayout android:orientation="horizontal" android:layout_width="wrap_content" android:layout_height="match_parent"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="已答/总数 : " /> <TextView android:id="@+id/textView_problem_answered_total" android:layout_width="wrap_content" android:layout_height="wrap_content" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text=" / " /> <TextView android:id="@+id/textView_problem_all_total" android:layout_width="wrap_content" android:layout_height="wrap_content" /> </LinearLayout> </LinearLayout> <!--下一题按钮--> <Button android:id="@+id/button_problem_next" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="40dp" android:layout_marginLeft="20dp" android:layout_marginRight="20dp" android:background="@drawable/linear_layout_middle_content" android:visibility="gone" android:text="下一题" /> <!--完成按钮--> <Button android:id="@+id/button_problem_complete" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="40dp" android:layout_marginLeft="20dp" android:layout_marginRight="20dp" android:background="@drawable/linear_layout_middle_content" android:visibility="gone" android:text="完成" /> </LinearLayout>
2. activity代码
package com.example.lenovo.computerbase; import android.content.Intent; import android.graphics.Color; import android.os.Handler; import android.os.Message; import android.support.annotation.IdRes; import android.support.v7.app.ActionBar; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.util.Log; import android.view.View; import android.widget.Button; import android.widget.ImageView; import android.widget.LinearLayout; import android.widget.RadioButton; import android.widget.RadioGroup; import android.widget.TextView; import com.example.lenovo.computerbase.bean.HttpAddress; import com.example.lenovo.computerbase.bean.Problem; import com.example.lenovo.computerbase.bean.ShowToast; import com.example.lenovo.computerbase.controller.ActivityCollectorController; import com.example.lenovo.computerbase.http.HttpConnection; import com.google.gson.Gson; import com.google.gson.reflect.TypeToken; import java.io.IOException; import java.lang.ref.WeakReference; import java.util.ArrayList; import okhttp3.Call; import okhttp3.Response; /* * 测试练习 * */ public class TestActivity extends AppCompatActivity implements View.OnClickListener{ //返回和退出布局LinearLayout private LinearLayout linearLayout_title_back,linearLayout_title_close; //返回和退出布局ImageView private ImageView imageView_title_back, imageView_title_close; //顶部中间显示文字区域 private TextView textView_title_text; private TextView textView_problem_number, textView_problem_title; private RadioGroup radioGroup_problem_group; private RadioButton radioButton_problem_option1, radioButton_problem_option2, radioButton_problem_option3, radioButton_problem_option4; private TextView textView_problem_answered_total, textView_problem_all_total; private Button button_problem_next, button_problem_complete; private ProblemHandler problemHandler = new ProblemHandler(this); HttpAddress httpAddress = new HttpAddress(); private String loginId; private int index = 0; ArrayList<Problem> problems = new ArrayList<>(); private int length; private int textColor; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_test); httpAddress = (HttpAddress) getApplication(); loginId = getIntent().getStringExtra("loginId"); initView(); requestProblem(); } public void initView(){ //将该Activity加入活动集合控制器 ActivityCollectorController.addActivity(this); //将导航栏隐藏 ActionBar actionBar = getSupportActionBar(); if (actionBar != null){ actionBar.hide(); } //返回 linearLayout_title_back = (LinearLayout)findViewById(R.id.linearLayout_title_back); linearLayout_title_back.setOnClickListener(this); //退出 linearLayout_title_close = (LinearLayout)findViewById(R.id.linearLayout_title_close); linearLayout_title_close.setOnClickListener(this); //返回和退出布局ImageView imageView_title_back = (ImageView)findViewById(R.id.imageView_title_back); imageView_title_back.setColorFilter(this.getResources().getColor(R.color.colorWhite)); imageView_title_close = (ImageView)findViewById(R.id.imageView_title_close); imageView_title_close.setColorFilter(this.getResources().getColor(R.color.colorWhite)); //顶部中间显示文字区域 textView_title_text = (TextView)findViewById(R.id.textView_title_text); textView_title_text.setText("随机练习"); textView_title_text.setTextColor(this.getResources().getColor(R.color.colorWhite)); textView_problem_number = (TextView) findViewById(R.id.textView_problem_number); textView_problem_title = (TextView) findViewById(R.id.textView_problem_title); radioGroup_problem_group = (RadioGroup) findViewById(R.id.radioGroup_problem_group); radioButton_problem_option1 = (RadioButton) findViewById(R.id.radioButton_problem_option1); radioButton_problem_option2 = (RadioButton) findViewById(R.id.radioButton_problem_option2); radioButton_problem_option3 = (RadioButton) findViewById(R.id.radioButton_problem_option3); radioButton_problem_option4 = (RadioButton) findViewById(R.id.radioButton_problem_option4); /* 得到RadioButton文字显示的默认颜色（黑色） * */ textColor = radioButton_problem_option1.getCurrentTextColor(); textView_problem_answered_total = (TextView) findViewById(R.id.textView_problem_answered_total); textView_problem_all_total = (TextView) findViewById(R.id.textView_problem_all_total); button_problem_next = (Button) findViewById(R.id.button_problem_next); button_problem_next.setOnClickListener(this); button_problem_complete = (Button) findViewById(R.id.button_problem_complete); button_problem_complete.setOnClickListener(this); } private static class ProblemHandler extends Handler{ private final WeakReference<TestActivity> weakReference; public ProblemHandler(TestActivity testActivity){ weakReference = new WeakReference<>(testActivity); } @Override public void handleMessage(Message message){ if (weakReference.get() == null) return; // something weakReference.get().problems = message.getData().getParcelableArrayList("problems"); weakReference.get().length = weakReference.get().problems.size(); weakReference.get().showProblems(weakReference.get().index); } }
//进行网络请求 public void requestProblem(){ httpAddress.setAddress("RandomTestServlet"); HttpConnection.sendOkHttpRequest(httpAddress.getAddress(), new okhttp3.Callback(){ @Override public void onFailure(Call call, IOException e) { Log.d("TestActivity", "请求服务器失败!"); } @Override public void onResponse(Call call, Response response) throws IOException { String responseData = response.body().string(); System.out.println(responseData); ArrayList<Problem> problems = new Gson().fromJson(responseData, new TypeToken<ArrayList<Problem>>(){}.getType()); putProblemHandler(problems); } }); } public void putProblemHandler(ArrayList<Problem> problems){ Message message = Message.obtain(); Bundle bundle = new Bundle(); bundle.putParcelableArrayList("problems", problems); message.setData(bundle); problemHandler.sendMessage(message); }
//通过下标取出单个Problem public void showProblems(int index){ if (index < length){ showProblem(problems.get(index)); } }
//在页面上显示题目信息 public void showProblem(Problem problem){ textView_problem_number.setText(String.valueOf(problem.getP_no())); textView_problem_title.setText(problem.getP_title()); radioButton_problem_option1.setText("A. " + problem.getP_option1()); radioButton_problem_option2.setText("B. " + problem.getP_option2()); radioButton_problem_option3.setText("C. " + problem.getP_option3()); radioButton_problem_option4.setText("D. " + problem.getP_option4()); /* 将RadioButton字体颜色设置为默认，是为了消除上一次选中留下的记录 * */ radioButton_problem_option1.setTextColor(textColor); radioButton_problem_option2.setTextColor(textColor); radioButton_problem_option3.setTextColor(textColor); radioButton_problem_option4.setTextColor(textColor);
// 显示已答题数和全部题数 showAnsweredTotal(index, length); RadioGroupProblemListener radioGroupProblemListener = new RadioGroupProblemListener(problem); //为RadioGroup设置监听 radioGroup_problem_group.setOnCheckedChangeListener(radioGroupProblemListener); } // 内部类（设置监听） class RadioGroupProblemListener implements RadioGroup.OnCheckedChangeListener{ private Problem problem; RadioGroupProblemListener(Problem problem){ this.problem = problem; } @Override public void onCheckedChanged(RadioGroup radioGroup, int id) { //选择选项1 if (id == radioButton_problem_option1.getId()) { /* 答案和选项1相等时，选项1显示GREEN颜色 否则，选项1显示RED颜色 并分别判断答案和其余每个选项是否相等，相等显示GREEN颜色 */ if (problem.getP_answer().equals(problem.getP_option1())){ radioButton_problem_option1.setTextColor(Color.GREEN); }else { radioButton_problem_option1.setTextColor(Color.RED); if (problem.getP_answer().equals(problem.getP_option2())){ radioButton_problem_option2.setTextColor(Color.GREEN); }else if (problem.getP_answer().equals(problem.getP_option3())){ radioButton_problem_option3.setTextColor(Color.GREEN); }else if (problem.getP_answer().equals(problem.getP_option4())){ radioButton_problem_option4.setTextColor(Color.GREEN); } } lastProblem(); } //选择选项2 else if (id == radioButton_problem_option2.getId()) { if (problem.getP_answer().equals(problem.getP_option2())){ radioButton_problem_option2.setTextColor(Color.GREEN); }else { radioButton_problem_option2.setTextColor(Color.RED); if (problem.getP_answer().equals(problem.getP_option1())){ radioButton_problem_option1.setTextColor(Color.GREEN); }else if (problem.getP_answer().equals(problem.getP_option3())){ radioButton_problem_option3.setTextColor(Color.GREEN); }else if (problem.getP_answer().equals(problem.getP_option4())){ radioButton_problem_option4.setTextColor(Color.GREEN); } } lastProblem(); } //选择选项3 else if (id == radioButton_problem_option3.getId()) { if (problem.getP_answer().equals(problem.getP_option3())){ radioButton_problem_option3.setTextColor(Color.GREEN); }else { radioButton_problem_option3.setTextColor(Color.RED); if (problem.getP_answer().equals(problem.getP_option1())){ radioButton_problem_option1.setTextColor(Color.GREEN); }else if (problem.getP_answer().equals(problem.getP_option2())){ radioButton_problem_option2.setTextColor(Color.GREEN); }else if (problem.getP_answer().equals(problem.getP_option4())){ radioButton_problem_option4.setTextColor(Color.GREEN); } } lastProblem(); } //选择选项4 else if (id == radioButton_problem_option4.getId()) { if (problem.getP_answer().equals(problem.getP_option4())){ radioButton_problem_option4.setTextColor(Color.GREEN); }else { radioButton_problem_option4.setTextColor(Color.RED); if (problem.getP_answer().equals(problem.getP_option1())){ radioButton_problem_option1.setTextColor(Color.GREEN); }else if (problem.getP_answer().equals(problem.getP_option2())){ radioButton_problem_option2.setTextColor(Color.GREEN); }else if (problem.getP_answer().equals(problem.getP_option3())){ radioButton_problem_option3.setTextColor(Color.GREEN); } } lastProblem(); } } }
//判断是否最后一题，最后一题时显示完成按钮，否则显示下一题按钮 public void lastProblem(){ System.out.println("index = " + index); System.out.println("length = " + length); showAnsweredTotal(index + 1, length); // 最后一题 if (index == length - 1){ System.out.println("index == length - 1 "); button_problem_complete.setVisibility(View.VISIBLE); }else { System.out.println("index != length - 1 "); button_problem_next.setVisibility(View.VISIBLE); } } public void showAnsweredTotal(int i, int j){ // 已答题数 textView_problem_answered_total.setText(String.valueOf(i)); textView_problem_answered_total.setTextColor(Color.GREEN); // 全部题数 textView_problem_all_total.setText(String.valueOf(j)); } /* 设置恢复RadioGroup默认状态 * */ public void defaultRadioGroup(){ /* * 循环使用RadioGroup时需要先取消监听，再清除选中记录 * */ // 1. 取消监听 radioGroup_problem_group.setOnCheckedChangeListener(null); // 2. 清除选中记录 radioGroup_problem_group.clearCheck(); } @Override public void onClick(View view) { switch (view.getId()){ //返回 case R.id.linearLayout_title_back: finish(); break; //退出 case R.id.linearLayout_title_close: ActivityCollectorController.finishAll(); Intent closeIntent = new Intent(getBaseContext(),LoginActivity.class); startActivity(closeIntent); new ShowToast(this,"您已退出!").showToast(); break; case R.id.button_problem_next: //题目索引加一 index ++; button_problem_next.setVisibility(View.GONE); // 清除上次选中记录 defaultRadioGroup(); showProblems(index); // 2. 重新请求problem break; case R.id.button_problem_complete: button_problem_complete.setVisibility(View.GONE); finish(); break; default: } } }