java - Android viewBinder 在 simpleCursorAdapter 上显示图像

Question

我已经创建了一个工作 ViewBinder 来与我的 simpleCursorAdapter 一起使用，并且一切正常。所需的图像按其应有的方式显示等。但是当我测试代码时，我在 View 绑定(bind)器中放置了一个日志，其中显示了显示图像的标准。当我查看 logCat 时，它显示了结果的两次迭代，如下所示。 (只有五个条目)。这将反过来创建我的 if 语句和结果图像显示的两次迭代。这不是显示问题，但它会产生一些冗余，因为它会在 listView 中显示图像两次。

日志文件:

columnIndex=1  categoryIdentifier = Supplier
columnIndex=1  categoryIdentifier = Customer
columnIndex=1  categoryIdentifier = Other
columnIndex=1  categoryIdentifier = Other
columnIndex=1  categoryIdentifier = Other
columnIndex=1  categoryIdentifier = Supplier
columnIndex=1  categoryIdentifier = Customer
columnIndex=1  categoryIdentifier = Other
columnIndex=1  categoryIdentifier = Other
columnIndex=1  categoryIdentifier = Other

运行viewBinder的代码是这样的:

代码:

private void fillData() {

    //The desired columns to be bound: 
    String[] from = new String[] { ContactsDB.COLUMN_CATEGORY, ContactsDB.COLUMN_LAST_NAME, ContactsDB.COLUMN_FIRST_NAME };
    //The XML views that the data will be bound to:
      int[] to = new int[] {R.id.contact_icon, R.id.label2, R.id.label};

   getLoaderManager().initLoader(0, null, this);
   adapter = new SimpleCursorAdapter(this, R.layout.contact_row, null, from, to, 0);
   // Set the ViewBinder to alternate the image in the listView
   adapter.setViewBinder(new SimpleCursorAdapter.ViewBinder() {
       public boolean setViewValue(View view, Cursor cursor, int columnIndex) {         
          // int viewId = view.getId();
           int categoryIndex = cursor.getColumnIndexOrThrow(ContactsDB.COLUMN_CATEGORY);

           if(columnIndex == categoryIndex)        
           {  
               String categoryIdentifier = cursor.getString(columnIndex);
               //switch categoryIdentifier
              if(categoryIdentifier.equalsIgnoreCase("Supplier")){
                  displayImage = (ImageView) view;
                  displayImage.setImageResource(R.drawable.supplier);
              }
              if(categoryIdentifier.equalsIgnoreCase("Other")){
                  displayImage = (ImageView) view;
                  displayImage.setImageResource(R.drawable.other);
              }    
               Log.v("TEST COMPARISON", "columnIndex=" + columnIndex + "  categoryIdentifier = " + categoryIdentifier);  

             return true;          
         } 
         return false;      
         } 
       });

    setListAdapter(adapter);
  } // end of fillData

  // Sort the names by last name, then by first name
  String orderBy = ContactsDB.COLUMN_LAST_NAME + " COLLATE NOCASE ASC"
  + "," + ContactsDB.COLUMN_FIRST_NAME + " COLLATE NOCASE ASC" ;

  // Creates a new loader after the initLoader () call
  @Override
  public Loader<Cursor> onCreateLoader(int id, Bundle args) {
    //String[] projection = { ContactsDB.ROW_ID, ContactsDB.COLUMN_LAST_NAME, ContactsDB.COLUMN_FIRST_NAME };
      String[] projection = { ContactsDB.ROW_ID, ContactsDB.COLUMN_CATEGORY, ContactsDB.COLUMN_LAST_NAME, ContactsDB.COLUMN_FIRST_NAME };
    CursorLoader cursorLoader = new CursorLoader(this,
    whateverContentProvider.CONTENT_URI, projection, null, null, orderBy);
    return cursorLoader;
  }

有人知道为什么会有这种冗余吗？

Answer 1

将 ListView android:layout_height 更改为 match_parent