CheckedTextView在编程选择时不绘制复选标记

Question

I'm writing an Android app that has a ListView with CheckedTextView items in it. It's basically a question with a variable number of answers. If you select one answer you can press "next" and see the next question.

I've written all the code to save the answers and go to the next questions, and I've also provided the user with a "previous" button to go back to the previous question. If the previous question already has an answer, I want that answer to be selected. And that's where the problems start.

Right now, I can get the position of the selected answer and I call listView.setItemChecked(pos, true) but the radio button is not selected.

if(selectedAnswer != null) {
    int pos = mAnswerAdapter.getPosition(selectedAnswer);
    if(pos != -1) {
        listAnswers.setItemChecked(pos, true);
    }
}

Only when I do something else, like drag down the statusbar does the view seem to refresh and draw the selected state of the radiobutton.

I fill the list with answers like this:

mAnswerAdapter = new AnswerArrayAdapter(getContext(), R.layout.listitem_answer, currentQuestion.getAnswers(), user.getLanguage());
listAnswers.setAdapter(mAnswerAdapter);
mAnswerAdapter.notifyDataSetChanged();

For reference:

The list_item layout:

<?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"/>

The adapter:

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);
        }
    }
}

The relevant fragment code (first call to openQuestion happens 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 selector drawable:

<?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>

Answer 1

I think you should call notifyDataSetChanged() after setting the answer to true so that the ListView can refresh its views immediatly

int pos = mAnswerAdapter.getPosition(selectedAnswer);
if(pos != -1) {
    listAnswers.setItemChecked(pos, true);
    mAnswerAdapter.notifyDataSetChanged()
}

Answer 2

For the simple checkbox, the attribute button will be used:

android:button="@drawable/questionnaire_answer_radio"

And for the CheckedTextView use the attribute checkMark:

android:checkMark="@drawable/questionnaire_answer_radio"

Answer 3

I've had similar problems facing the interface while using things such as radio buttons. Pass along a boolean value to the getView and then inside the getView state that:

boolean checked; //The variable being passed
.
.
.

if(item.getBoolean){   
 radioButton.setChecked(true);
}
else
{
radioButton.setChecked(false);
}

Then when anyone clicks to change the button implement the following in the onClick function of the radioButton:

if(item.getBoolean){   
 item.setBoolean(false)
 mAnswerAdapter.notifyDatasetChanged();
}
else
{
item.setBoolean(true)
 mAnswerAdapter.notifyDatasetChanged();
}

I hope this helps

Answer 4

I can't remember, since i have not used ListView for lists for awhile. If you use RecyclerView, u bind that with onBindViewHolder to adapter, the equivalent method of the ListView should do the trick. But RecyclerView is superior to Listview.

Creata field, named selectedPosition for instance, inside the Adapter class. When you invoke notifyDatasetChanged , onBindView method of RecyclerView.Adapter is invoked. Check position that you want to be selected with the selectedPosition field of the adapter and change the view with that position as you like.

public void onBindViewHolder(MyViewHolder holder, final int position) {
    holder.tvCamMenu.setText(data.get(position));
    if (selectedPosition == position) {
        holder.tvCamMenu.setTextColor(Color.YELLOW);
    } else {
        holder.tvCamMenu.setTextColor(Color.WHITE);
    }
}

This is the snippet i use to set color of the selected column inside the horizontal RecyclerView. Finally call notifyDatasetChanged and the view will change as you modify it to be when selected.