UITextField占位符文本覆盖问题

我有一个带有三个表格视图单元格的表格视图。在单元格配置期间，我向每个单元格添加一个UITextField，并且还在所有文本字段上设置了占位符值。加载表视图时，最终结果如下所示：

我遇到的问题是，当我滚动出现任何“离屏”的单元格时，当它们再次出现时，占位符文本变得越来越暗，如下所示：

然后，当我尝试通过在其中键入名称或以编程方式更改最后一个单元格上的占位符值来更改UITextField字符串值时，这些属性的旧值会保留，而新值将覆盖在该单元格中，如下所示：

Here are the methods responsible for configuring those cells:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];

    // Configure the cell...
    [self configureCell:cell forIndexPath:indexPath];

    return cell;
}

- (void)configureCell:(UITableViewCell *)cell forIndexPath:(NSIndexPath *)indexPath
{
    for (UIView *subview in cell.contentView.subviews) {
        [subview removeFromSuperview];
    }

    cell.backgroundColor = [UIColor whiteColor];
    cell.autoresizesSubviews = YES;
    cell.clearsContextBeforeDrawing = YES;
    CGRect textFieldFrame = cell.bounds;
    textFieldFrame.origin.x += 10;
    textFieldFrame.size.width -= 10;

    UITextField *textField = [[UITextField alloc] initWithFrame:textFieldFrame];
    textField.adjustsFontSizeToFitWidth = YES;
    textField.textColor = [UIColor lightGrayColor];
    textField.enabled = YES;
    textField.userInteractionEnabled = NO;
    textField.autoresizingMask = UIViewAutoresizingFlexibleWidth;
    textField.clearsContextBeforeDrawing = YES;
    textField.clearsOnBeginEditing = YES;

    if (indexPath.section == ATTAddNewTimerSectionName) {
        textField.placeholder = @"Name";
        textField.userInteractionEnabled = YES;
        textField.delegate = self;
        textField.returnKeyType = UIReturnKeyDone;
        textField.clearButtonMode = UITextFieldViewModeWhileEditing;
    } else if (indexPath.section == ATTAddNewTimerSectionDate) {
        textField.placeholder = @"Date/Time";
        cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
    } else if (indexPath.section == ATTAddNewTimerSectionCalendar) {
        if (self.userCalendarEvent == nil) {
            textField.placeholder = @"See list of calendar events";
        } else {
            textField.placeholder = nil;
            textField.placeholder = self.userCalendarEvent.title;
        }
        cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
    }
    [cell addSubview:textField];
}

As you can see, I have tried various things, like removing all the subviews before adding a new view to the cell or setting -[UIView setClearsContextBeforeDrawing:YES] on both the cell and the UITextView and even setting the placeholder value to nil without success.

Any pointers would be much appreciated!