单选按钮被取消并在列表视图滚动中自动检查

我有一个程序，其中我有多个问题和2个选项（radiobuttons）当我检查1并滚动listview它取消选中。 我会发布整个代码，请帮我解决。 我认为适配器类有问题

主要活动

public class MainActivity extends AppCompatActivity { ListView simpleList; String[] questions; Button submit; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // get the string array from string.xml file questions = getResources().getStringArray(R.array.questions); // get the reference of ListView and Button simpleList = (ListView) findViewById(R.id.simpleListView); submit = (Button) findViewById(R.id.submit); // set the adapter to fill the data in the ListView CustomAdapter customAdapter = new CustomAdapter(getApplicationContext(), questions); simpleList.setAdapter(customAdapter); // perform setOnClickListerner event on Button submit.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { String message = ""; // get the value of selected answers from custom adapter for (int i = 0; i < CustomAdapter.selectedAnswers.size(); i++) { message = message + "\n" + (i + 1) + " " + CustomAdapter.selectedAnswers.get(i); } // display the message on screen with the help of Toast. Toast.makeText(getApplicationContext(), message, Toast.LENGTH_LONG).show(); } }); } 

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定制适配器

 public class Questions_Adapter extends BaseAdapter { Activity context; String[] questionsList; String age_range; LayoutInflater inflter; public static ArrayList selectedAnswers; public Questions_Adapter(Activity applicationContext, String[] questionsList, String age_range) { context = applicationContext; this.questionsList = questionsList; this.age_range = age_range; // initialize arraylist and add string for all the questions selectedAnswers = new ArrayList(); for (int i = 0; i < questionsList.length; i++) { selectedAnswers.add(0); } inflter = (LayoutInflater.from(applicationContext)); } @Override public int getCount() { return questionsList.length; } @Override public Object getItem(int i) { return null; } @Override public long getItemId(int i) { return 0; } private class Viewholder{ TextView question; RadioButton op1, op2, op3, op4, op5, op6; } @Override public View getView(final int position, View view, ViewGroup viewGroup) { Viewholder viewholder; LayoutInflater inflater = context.getLayoutInflater(); if (view == null){ viewholder = new Viewholder(); view = inflater.inflate(R.layout.list_items,null); viewholder.question = (TextView) view.findViewById(R.id.question); viewholder.op1 = (RadioButton) view.findViewById(R.id.yes); viewholder.op2 = (RadioButton) view.findViewById(R.id.no); viewholder.op3 = (RadioButton) view.findViewById(R.id.op); viewholder.op4 = (RadioButton) view.findViewById(R.id.op4); viewholder.op5 = (RadioButton) view.findViewById(R.id.op5); viewholder.op6 = (RadioButton) view.findViewById(R.id.op6); view.setTag(viewholder); } else { viewholder = (Viewholder) view.getTag(); } // perform setOnCheckedChangeListener event on yes button viewholder.op1.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { @Override public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { // set Yes values in ArrayList if RadioButton is checked if (isChecked) selectedAnswers.set(position, 1); } }); viewholder.op2.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { @Override public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { if (isChecked) selectedAnswers.set(position, 2); } }); viewholder.op3.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { @Override public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { if (isChecked) selectedAnswers.set(position, 3); } }); viewholder.op4.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { @Override public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { if (isChecked) selectedAnswers.set(position, 4); } }); viewholder.op5.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { @Override public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { if (isChecked) selectedAnswers.set(position, 10); } }); viewholder.op6.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { @Override public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { if (isChecked) selectedAnswers.set(position, 0); } }); // set the value in TextView viewholder.op1.setText("None or Little of a time"); viewholder.op2.setText("Some of the time"); viewholder.op3.setText("A good part of the time"); viewholder.op4.setText("Most or All of the time"); viewholder.op5.setText("Yes"); viewholder.op6.setText("No"); viewholder.question.setText(questionsList[position]); if(age_range.equals("ZSDS")){ viewholder.op5.setVisibility(View.GONE); viewholder.op6.setVisibility(View.GONE); } if(age_range.equals("GDS")){ viewholder.op1.setVisibility(View.GONE); viewholder.op2.setVisibility(View.GONE); viewholder.op3.setVisibility(View.GONE); viewholder.op4.setVisibility(View.GONE); } return view; } } 

Answer 1

首先，您需要在模型中保存tick（复选框选择） ，例如isSelected = true并调用notifyDataSetChanged 。 然后在getView（）方法内部你需要检查这个标志并根据它设置复选框状态。

Answer 2

基本上你的视图是在每次滚动后重新生成的，因为你没有检查视图是否为null 。

您必须检查第一个视图并使用持有者，而不是每次都创建小部件的新对象。 这是解决方案希望，它将与您的列表视图一起使用。

 public class CustomAdapter extends BaseAdapter { static class ViewHolder { TextView question ; RadioButton yes,no; } Context context; String[] questionsList; LayoutInflater inflter; public static List selectedAnswers; public CustomAdapter(Context applicationContext, String[] questionsList) { context = applicationContext; this.questionsList = questionsList; // initialize arraylist and add static string for all the questions selectedAnswers = new ArrayList<>(); for (int i = 0; i < questionsList.length; i++) { selectedAnswers.add("Not Attempted"); } inflter = (LayoutInflater.from(applicationContext)); } @Override public int getCount() { return questionsList.length; } @Override public Object getItem(int i) { return null; } @Override public long getItemId(int i) { return 0; } @Override public View getView(final int i, View view, ViewGroup viewGroup) { ViewHolder holder = new ViewHolder(); if(view==null){ view = inflter.inflate(R.layout.list_items, null); // get the reference of TextView and Button's holder.question = (TextView) view.findViewById(R.id.question); holder.yes = (RadioButton) view.findViewById(R.id.yes); holder.no = (RadioButton) view.findViewById(R.id.no); // perform setOnCheckedChangeListener event on yes button view.setTag(holder); }else{ holder = (ViewHolder) view.getTag(); } holder.yes.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { @Override public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { // set Yes values in ArrayList if RadioButton is checked if (isChecked) selectedAnswers.set(i, "Yes"); } }); // perform setOnCheckedChangeListener event on no button holder.no.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { @Override public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { // set No values in ArrayList if RadioButton is checked if (isChecked) selectedAnswers.set(i, "No"); } }); // set the value in TextView question.setText(questionsList[i]); return view; } } 

Answer 3

当您滚动时，视图将被回收以显示项目，因此选择不在视图范围内的其他旧列表项目将会出现错误的项目。 因此，在调用get视图时，您需要重置单选按钮的选择。

因此，您可以在getVeiw()方法中添加以下代码，以使选择正常工作

  if(position < selectedAnswers.size() && selectedAnswers.get(position) != null) { switch(selectedAnswers.get(position)) { case 1: viewholder.op1.setChecked(true); break; case 2: viewholder.op2.setChecked(true); break; case 3: viewholder.op3.setChecked(true); break; case 4: viewholder.op4.setChecked(true); break; case 10: viewholder.op5.setChecked(true); break; case 0: viewholder.op6.setChecked(true); break; default: viewholder.op1.setChecked(false); viewholder.op2.setChecked(false); viewholder.op3.setChecked(false); viewholder.op4.setChecked(false); viewholder.op5.setChecked(false); viewholder.op6.setChecked(false); } } 

这将在列表视图的滚动上设置您选择的单选按钮。