Question

Into the cellForRowAtIndexPath: method of an UITableViewController class I am using the next code to show a cell that contains an UITextView.

Sometimes when I scroll the table that contains the cell and then I scroll the cell UITextView, it shows the cell text reprinted (as if there were two UITextView objects, instead of one, into the cell).

What can I do to solve this problem?

static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];    
if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}

cell.contentView.bounds = CGRectMake(0, 0, cell.frame.size.width, cell.frame.size.height);
cell.selectionStyle = UITableViewCellSelectionStyleNone;

UITextView *textView = [[UITextView alloc] initWithFrame:cell.contentView.bounds];
                textView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
textView.editable = NO;
textView.scrollEnabled = YES;
textView.backgroundColor = [UIColor clearColor];
textView.font = [UIFont fontWithName:@"Helvetica" size:14.0];
textView.text = self.description;

[cell.contentView addSubview:textView];
[textView release];

Answer 1

UITableView reuses its cells to increase scrolling performance. Whenever a cell is being reused, you are adding a new text view to the cell (although one is already there).

You should move the creation of the text view (and adding it to the cell) into the if (cell == nil) block. Inside this block, also give the text view a unique tag and use this tag property to access the text view from outside the block. See Apple’s table view sample code for examples of this pattern, it is being used a lot.