在 Gridview 中选中一个时，多个复选框被（取消）选中 - Android

Question

所以我有一个 Gridview，其中每个网格项都由一个 ImageView 和一个 Checkbox 组成。它调用图像适配器来动态填充网格。现在，当我 select 一个复选框时，比方说数字 5，另一个像数字 12 这样的复选框会自动 selected。 deselection 类似。我不明白为什么会这样。任何帮助将不胜感激。谢谢！

public class SignupFarmerCrop extends ActionBarActivity implements View.OnClickListener {

GridView gridView;
private ImageAdapter adpt;
private List<DistrictCommodity> localResponse;
private MediaPlayer mp;
private boolean[] thumbnailsselection;
private int count;

private PreferencesHelper oldSignup;
private String district;

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

    setVolumeControlStream(AudioManager.STREAM_MUSIC);
    ImageButton sound = (ImageButton) findViewById(R.id.button);
    sound.setOnClickListener(this);

    oldSignup = new PreferencesHelper(this);
    district = oldSignup.getStringPreferences("districtId");
    String language = Locale.getDefault().getLanguage();
    if (language.equals("en"))
        language = "L001";
    else
        language = "L002";

    // Exec async load task
    new EndpointsDistrictCropAsyncTask().execute(new Pair<Context, String>(this, district),
            new Pair<Context, String>(this, language));

    gridView = (GridView) findViewById(R.id.gridView1);
    adpt = new ImageAdapter(this, localResponse);
    gridView.setAdapter(adpt);

public void onClick(View v) {
    if (mp != null) mp.release();

    mp = MediaPlayer.create(this, R.raw.fname);
    mp.start();
}

/** Called when the user clicks a crop button */
public void goConfirm(View view) {
    // Do something in response to button
    Intent intent = new Intent(this, SignupConfirmActivity.class);
    startActivity(intent);
}

@Override
protected void onDestroy() {
    if(null!=mp){
        mp.release();
    }
    super.onDestroy();
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    // Inflate the menu items for use in the action bar
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.menu_signup_farmer_crop, menu);
    return super.onCreateOptionsMenu(menu);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    return super.onOptionsItemSelected(item);
}

public class ImageAdapter extends BaseAdapter {
    private Context context;
    private List<DistrictCommodity> crops;
    private final Logger logger = Logger.getLogger(ImageAdapter.class.getName());

    public ImageAdapter(Context context, List<DistrictCommodity> activeResponses) {
        this.context = context;
        this.crops = activeResponses;
    }

    public View getView(int position, View convertView, ViewGroup parent) {

        View gridView = convertView;
        ViewHolder holder;
        if (gridView == null) {
            holder = new ViewHolder();
            LayoutInflater inflater = (LayoutInflater) context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            gridView = inflater.inflate(R.layout.activity_signup_crop_grid, null);
            holder.checkbox = (CheckBox) gridView.findViewById(R.id.grid_item_label);
            holder.imageview = (ImageView) gridView.findViewById(R.id.grid_item_image);

            gridView.setTag(holder);
        }

        else {
            holder = (ViewHolder) gridView.getTag();
        }

        holder.checkbox.setId(position);
        holder.imageview.setId(position);

        holder.checkbox.setOnClickListener(new View.OnClickListener() {

            public void onClick(View v) {
                CheckBox cb = (CheckBox) v;
                int id = cb.getId();
                logger.warning("Id of checkbox is: " + id);
                if (thumbnailsselection[id]) {
                    cb.setChecked(false);
                    thumbnailsselection[id] = false;
                } else {
                    cb.setChecked(true);
                    thumbnailsselection[id] = true;
                }
            }
        });


        holder.checkbox.setText(crops.get(position).getCommodity());

        String crop = crops.get(position).getType();
        logger.warning("Image file called is @drawable/" + crop + ".png and context is: " + context.getPackageName());
        Drawable drawable = context.getResources().getDrawable(context.getResources()
                .getIdentifier("@drawable/potato", null, context.getPackageName()));

        holder.imageview.setImageDrawable(drawable);
        holder.id = position;

        return gridView;
    }

    @Override
    public int getCount() {
        return count;
    }

    @Override
    public Object getItem(int position) {
        return position;
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    public void setActiveDeals(List<DistrictCommodity> activeResponses) {
        this.crops = activeResponses;
    }
}

class ViewHolder {
        ImageView imageview;
        CheckBox checkbox;
        int id;
}

}

Answer 1

您在 thumbnailsselection 中保存复选框在被单击时的状态，但您没有在 getView() 中使用该状态来设置复选框的初始外观。因此，您可能会从回收视图中获取随机复选框状态。

使用 thumbnailsselection 中的状态调用 holder.checkbox.setState() 以创建具有正确复选框外观的 GridView 项。

Answer 2

MainActivity.java

private void enterEditMode() {
    try {
        listView.setAdapter(null);
        listView.setOnItemClickListener(null);

        db = new MySQLiteHelper(this);

        //call the note object which hold all note object
        List<note> note = db.getAllNotes();

        int total = note.size();

        //declare the values with specific number
        String[] values = new String[total];

        //add all the note innto the values
        int counter = 0;

        for (note note1 : note) {
            values[counter] = note1.getSubject();
            counter++;
        }
        db.close();
        cbAdapter = new checkboxListviewAdapter(this,values);
        // Assign adapter to ListView
        listView.setAdapter(cbAdapter);
        cbAdapter.notifyDataSetChanged();

    } catch (Exception e) {
        //tell user to send report
        showMessage("Error!");
    }
}

checkboxListviewAdapter.java

public class checkboxListviewAdapter extends BaseAdapter{

Context context;
String[] subjectList;
Boolean[] selectedList;
private LayoutInflater inflater;


public checkboxListviewAdapter (Context context, String[] subjectList ) {

    this.context = context;
    this.subjectList = subjectList;
    selectedList = new Boolean[subjectList.length];
    inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    for (int i = 0; i < selectedList.length; i++){
        selectedList[i] = false;
    }
}

@Override
public int getCount() {
    return subjectList.length;
}

@Override
public Object getItem(int position) {
    return subjectList[position];
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public View getView(final int position, View convertView, ViewGroup parent) {

    Holder holder = null;

    if (convertView == null) {
        holder = new Holder();
        convertView = inflater.inflate(R.layout.checkbox_listview_text_black, null);
        holder.tv = (TextView) convertView.findViewById(R.id.textview1);
        holder.cb = (CheckBox) convertView.findViewById(R.id.checkBox1);
        convertView.setTag(holder);
    } else {
        holder = (Holder) convertView.getTag();

    }
    holder.cb.setChecked(selectedList[position]);
    holder.tv.setText(subjectList[position]);
    holder.cb.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if(selectedList[position] == false) {
                selectedList[position] = true;
            } else {
                selectedList[position] = false;
            }
        }
    });
    return convertView;
}

static class Holder {
    TextView tv;
    CheckBox cb;

}

}

解释：

在checkboxListviewAdapter.java

1) 假设您的列表视图中有 10 个复选框。因此，创建一个 boolean[] 来保存所有复选框的布尔值。

private boolean[] booleanList = new boolean[10];

2) 在您的构造函数中，使用 for 循环将 booleanList 设置为 false。

 public checkboxListviewAdapter (Context context, String[] subjectList ) {

    //this.context = context;
    //this.subjectList = subjectList;
    //selectedList = new Boolean[subjectList.length];
    //inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    for (int i = 0; i < selectedList.length; i++){
        selectedList[i] = false;
    }
}

3) 现在，在您的 getView 中，添加以下代码以从 booleanList 获取布尔值，并在每次滚动列表视图时设置布尔值。

holder.cb.setChecked(selectedList[position]);

4) 最后，要向您的复选框添加一个侦听器，请使用 OnClickListener。

holder.cb.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if(selectedList[position] == false) {
                selectedList[position] = true;
            } else {
                selectedList[position] = false;
            }
        }
    });

5) 运行代码并检查结果。

在 Gridview 中选中一个时，多个复选框被（取消）选中 - Android

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