Android 使用 Cursor Adapter 在 ListView 中保存复选框状态 [英] Android save Checkbox State in ListView with Cursor Adapter

问题描述

在使用 Cursor 适配器时，我找不到保存复选框状态的方法.其他一切正常，但如果我点击一个复选框，它会在回收时重复.我见过使用数组适配器的示例，但由于我缺乏经验，我发现很难将其转换为使用游标适配器.有人可以给我一个如何去做的例子.任何帮助表示赞赏.

I cant find a way to save the checkbox state when using a Cursor adapter. Everything else works fine but if i click on a checkbox it is repeated when it is recycled. Ive seen examples using array adapters but because of my lack of experience im finding it hard to translate it into using a cursor adapter. Could someone give me an example of how to go about it. Any help appreciated.

private class PostImageAdapter extends CursorAdapter {

    private static final int s = 0;
    private int layout;
    Bitmap bm=null;
    private String PostNumber;
    TourDbAdapter mDbHelper;


    public PostImageAdapter (Context context, int layout, Cursor c, String[] from, int[] to, String Postid) {

        super(context, c);
        this.layout = layout;
        PostNumber = Postid;

     mDbHelper = new TourDbAdapter(context);
     mDbHelper.open();

    }

    @Override
    public View newView(Context context, final Cursor c, ViewGroup parent) {

     ViewHolder holder;

     LayoutInflater inflater=getLayoutInflater();
     View row=inflater.inflate(R.layout.image_post_row, null);       

   holder = new ViewHolder();

   holder.Description = (TextView) row.findViewById(R.id.item_desc);
   holder.cb = (CheckBox) row.findViewById(R.id.item_checkbox);
   holder.DateTaken = (TextView) row.findViewById(R.id.item_date_taken);
   holder.Photo = (ImageView) row.findViewById(R.id.item_thumb);

   row.setTag(holder);

 int DateCol = c.getColumnIndex(TourDbAdapter.KEY_DATE);
 String Date = c.getString(DateCol);

 int DescCol = c.getColumnIndex(TourDbAdapter.KEY_CAPTION);
 String Description = c.getString(DescCol);    

 int FileNameCol = c.getColumnIndex(TourDbAdapter.KEY_FILENAME); 
 final String FileName = c.getString(FileNameCol);

 int PostRowCol = c.getColumnIndex(TourDbAdapter.KEY_Post_ID); 
 String RowID = c.getString(PostRowCol);

 String Path = "sdcard/Tourabout/Thumbs/" + FileName + ".jpg";    
 Bitmap bm = BitmapFactory.decodeFile(Path, null); 

 holder.Photo.setImageBitmap(bm);
 holder.DateTaken.setText(Date);
 holder.Description.setText(Description);

 holder.cb.setOnClickListener(new OnClickListener() {  
    @Override
 public void onClick(View v) {
    CheckBox cBox = (CheckBox) v;
    if (cBox.isChecked()) {

      mDbHelper.UpdatePostImage(FileName, PostNumber);

    } 
    else if (!cBox.isChecked()) {    
      mDbHelper.UpdatePostImage(FileName, "");

    }

  }
});
return row;

};

    @Override
    public void bindView(View row, Context context, final Cursor c) {  

     ViewHolder holder;
     holder = (ViewHolder) row.getTag();   

      int DateCol = c.getColumnIndex(TourDbAdapter.KEY_DATE);
         String Date = c.getString(DateCol);

         int DescCol = c.getColumnIndex(TourDbAdapter.KEY_CAPTION);
         String Description = c.getString(DescCol);    

         int FileNameCol = c.getColumnIndex(TourDbAdapter.KEY_FILENAME); 
      final String FileName = c.getString(FileNameCol);

      int PostRowCol = c.getColumnIndex(TourDbAdapter.KEY_Post_ID); 
         String RowID = c.getString(PostRowCol);

      String Path = "sdcard/Tourabout/Thumbs/" + FileName + ".jpg";    
         Bitmap bm = BitmapFactory.decodeFile(Path, null); 

        File x = null;

         holder.Photo.setImageBitmap(bm);
         holder.DateTaken.setText(Date);
         holder.Description.setText(Description);

         holder.cb.setOnClickListener(new OnClickListener() {  
        @Override
        public void onClick(View v) {
         CheckBox cBox = (CheckBox) v;
         if (cBox.isChecked()) {

               mDbHelper.UpdatePostImage(FileName, PostNumber);

         } 
         else if (!cBox.isChecked()) {    
               mDbHelper.UpdatePostImage(FileName, "");

         }

        }
       });

    }

}  

static class ViewHolder{
  TextView Description;
  ImageView Photo;
  CheckBox cb;
  TextView DateTaken;
}
}

推荐答案

我建议您使用 Android 对多项选择列表的内置支持 (CHOICE_MODE_MULTIPLE).

I would recommend you use Android's built-in support for multiple-choice lists (CHOICE_MODE_MULTIPLE).

List11.javaSDK 示例演示了这一点.您还可以从我的一个教程中找到一个使用它的项目此处.

你仍然可以在你自己的布局中使用这个技术，只要你包含一个 CheckedTextView 和 android:id="@android:id/text1" 如下所示在 android.R.layout.simple_list_item_multiple_choice 资源中，您的 SDK 附带了该资源的副本.

You can still use this technique with your own layout, so long as you include a CheckedTextView with android:id="@android:id/text1" as shown in the android.R.layout.simple_list_item_multiple_choice resource, a copy of which ships with your SDK.

另外，请参阅这个问题和这个问题 和 这个问题 和这个问题.

Also, see this question and this question and this question and this question.

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