我正在编写一个Android应用程序,其中包含一个带有CheckedTextView项的ListView。它基本上是一个问题,有可变数量的答案。如果您选择一个答案,您可以按“下一步”并查看下一个问题。
我已经编写了保存答案并进入下一个问题的所有代码,并且还为用户提供了“上一个”按钮以返回上一个问题。如果以前的问题已经有答案,我希望选择该答案。这就是问题的开始。
现在,我可以获取所选答案的位置,并调用
适配器:
相关代码片段(第一次调用openQuestion发生在onStart):
我已经编写了保存答案并进入下一个问题的所有代码,并且还为用户提供了“上一个”按钮以返回上一个问题。如果以前的问题已经有答案,我希望选择该答案。这就是问题的开始。
现在,我可以获取所选答案的位置,并调用
listView.setItemChecked(pos, true)
但是单选按钮没有被选中。if(selectedAnswer != null) {
int pos = mAnswerAdapter.getPosition(selectedAnswer);
if(pos != -1) {
listAnswers.setItemChecked(pos, true);
}
}
只有当我进行其他操作,例如向下拖动状态栏时,视图似乎才会刷新并绘制单选按钮的选定状态。
我使用以下方式填充答案列表:
mAnswerAdapter = new AnswerArrayAdapter(getContext(), R.layout.listitem_answer, currentQuestion.getAnswers(), user.getLanguage());
listAnswers.setAdapter(mAnswerAdapter);
mAnswerAdapter.notifyDataSetChanged();
供参考:
列表项布局:
<?xml version="1.0" encoding="utf-8"?>
<CheckedTextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:minHeight="?attr/listPreferredItemHeightSmall"
android:drawableStart="@drawable/questionnaire_answer_radio"
android:drawablePadding="10dp"
android:gravity="center_vertical"
android:paddingStart="5dp"
android:paddingEnd="5dp"
android:textColor="@android:color/white"
android:id="@+id/questionnaire_answer_checkbox"/>
适配器:
package be.iminds.mresist;
import android.content.Context;
import android.support.annotation.NonNull;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.CheckedTextView;
import java.util.List;
import be.iminds.mresist.models.QuestionnaireDefinition;
import butterknife.BindView;
import butterknife.ButterKnife;
public class AnswerArrayAdapter extends ArrayAdapter<QuestionnaireDefinition.Answer> {
private String mLang;
private Context mContext;
public AnswerArrayAdapter(Context context, int textViewResourceId, List<QuestionnaireDefinition.Answer> answers, final String lang) {
super(context, textViewResourceId, answers);
this.mContext = context;
this.mLang = lang;
}
@NonNull
@Override
public View getView(int position, View convertView, ViewGroup parent) {
LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
AnswerArrayAdapter.ViewHolder holder = null;
QuestionnaireDefinition.Answer item = getItem(position);
if (convertView == null) {
convertView = inflater.inflate(R.layout.listitem_answer, parent, false);
holder = new AnswerArrayAdapter.ViewHolder(convertView);
convertView.setTag(holder);
} else
holder = (AnswerArrayAdapter.ViewHolder) convertView.getTag();
holder.answerText.setText(item.getAnswer(mLang));
return convertView;
}
static class ViewHolder {
@BindView(R.id.questionnaire_answer_checkbox) CheckedTextView answerText;
public ViewHolder(View view) {
ButterKnife.bind(this, view);
}
}
}
相关代码片段(第一次调用openQuestion发生在onStart):
/**
* Opens the question with the corresponding index
* @param questionIdx
*/
private void openQuestion(int questionIdx)
{
currentQuestionIdx = questionIdx;
final Question currentQuestion = getCurrentQuestion();
txtQuestionTitleCounter.setText(String.format(getString(R.string.questionnaire_counter), questionIdx + 1, qAssignment.getDefinition().getQuestions().size()));
txtQuestion.setText(currentQuestion.getQuestion(user.getLanguage()));
mAnswerAdapter = new AnswerArrayAdapter(getContext(), R.layout.listitem_answer, currentQuestion.getAnswers(), user.getLanguage());
listAnswers.setAdapter(mAnswerAdapter);
mAnswerAdapter.notifyDataSetChanged();
//If it's not the last question and there are more questions than one, make the next button visible
if(!isLastQuestion(currentQuestionIdx) && qAssignment.getDefinition().getQuestions().size() > 1)
mNextButton.setVisibility(View.VISIBLE);
else
mNextButton.setVisibility(View.GONE);
//If it's not the first question and there are more questions than one, make the previous button visible
if(!isFirstQuestion(currentQuestionIdx) && qAssignment.getDefinition().getQuestions().size() > 1)
mPreviousButton.setVisibility(View.VISIBLE);
else
mPreviousButton.setVisibility(View.GONE);
//If the question's already been answered, fill in the answer
markPreviousAnswer(currentQuestion);
}
/**
* Marks a previously selected answer
* @param currentQuestion
*/
private void markPreviousAnswer(Question currentQuestion) {
if(qAssignment.getAnswerValues() != null && qAssignment.getAnswerValues().containsKey(currentQuestion.getQuestionKey())) {
//Value of answer
Integer value = qAssignment.getAnswerValues().get(currentQuestion.getQuestionKey());
QuestionnaireDefinition.Answer selectedAnswer = null;
for(QuestionnaireDefinition.Answer answer: currentQuestion.getAnswers()) {
if(answer.getValue() == value) {
selectedAnswer = answer;
break;
}
}
if(selectedAnswer != null) {
int pos = mAnswerAdapter.getPosition(selectedAnswer);
if(pos != -1) {
listAnswers.setItemChecked(pos, true);
}
}
}
}
CheckedTextView选择器可绘制项:
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_pressed="true">
<shape android:shape="oval">
<size android:width="16dp" android:height="16dp"/>
<solid android:color="@color/colorPrimaryDarker"/>
<stroke android:color="@android:color/white" android:width="2dp"/>
</shape>
</item><!-- pressed -->
<item android:state_checked="true">
<shape android:shape="oval">
<size android:width="16dp" android:height="16dp"/>
<solid android:color="@color/colorPrimaryDarker"/>
<stroke android:color="@android:color/white" android:width="2dp"/>
</shape>
</item> <!-- checked -->
<item>
<shape android:shape="oval" android:innerRadius="10dp">
<size android:width="16dp" android:height="16dp"/>
<stroke android:color="@android:color/white" android:width="1dp"/>
</shape>
</item> <!-- default -->
</selector>
CheckedTextView
中添加android:checkMark="?android:attr/listChoiceIndicatorSingle"
属性,并设置listviewandroid:choiceMode="singleChoice"
,然后检查一下。 - blizzardsetChecked(pos,true)
是否被正确调用了? - blizzardlistAnswers.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
- Yoni Gross