Question

在我的应用程序中，我已经自定义了UITableViewCell并正在使用其contentView属性。但现在问题是细胞中的数据有时会进入不同的细胞。例如：当滚动到底部或向上滚动时，单元格3中的数据将进入单元格8或9。这是我在cellForRowAtIndexPath中使用的代码：

- (UITableViewCell *)tableView:(UITableView *)tv cellForRowAtIndexPath:(NSIndexPath *)indexPath
{

    static NSString *CellIdentifier = @"Cell";
    CGFloat fontSize = [UIFont systemFontSize];
    CGFloat smallFontSize = [UIFont smallSystemFontSize];
    UITableViewCell *cell = [tv dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:CellIdentifier]autorelease];
        mainLabel = [[[UILabel alloc] initWithFrame:CGRectMake(5,0,150,42)] autorelease];
        mainLabel.font = [UIFont systemFontOfSize:smallFontSize];
        mainLabel.numberOfLines = 3;
        mainLabel.lineBreakMode = UILineBreakModeWordWrap;
        mainLabel.backgroundColor = [UIColor clearColor];
        mainLabel.autoresizingMask = UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleHeight;
        [cell.contentView addSubview:mainLabel];

        secondLabel = [[[UILabel alloc] initWithFrame:CGRectMake(160,0,160,42)] autorelease];
        secondLabel.font = [UIFont systemFontOfSize:smallFontSize];
        secondLabel.numberOfLines = 3;
        secondLabel.lineBreakMode = UILineBreakModeWordWrap;
        secondLabel.backgroundColor = [UIColor clearColor];
        secondLabel.autoresizingMask = UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleHeight;
        [cell.contentView addSubview:secondLabel];


    }
    cell.accessoryType = UITableViewCellAccessoryNone;
    cell.selectionStyle = UITableViewCellSelectionStyleNone;
    cell.textLabel.font = [UIFont systemFontOfSize:smallFontSize];
    cell.detailTextLabel.font = [UIFont systemFontOfSize:smallFontSize];
    NSArray * titles = [[NSArray alloc] initWithObjects:@"Project ID", @"Status", @"Approval Date", @"Closing Date", @"Country",@"Region Name", @"Env", @"Team Full Name",@"Borrower", @"Impagency", @"Lending Cost", @"IBRDPlus", nil];

    switch (indexPath.section) {
        case 0:

            mainLabel.text = [titles objectAtIndex:indexPath.row];
            mainLabel.adjustsFontSizeToFitWidth = YES;
            mainLabel.numberOfLines = 4;
            mainLabel.lineBreakMode = UILineBreakModeWordWrap;

            secondLabel.text = [self.basic objectAtIndex:indexPath.row];
            secondLabel.adjustsFontSizeToFitWidth = YES;
            secondLabel.numberOfLines = 4;
            secondLabel.lineBreakMode = UILineBreakModeWordWrap;
            break;
        case 1:

            mainLabel.text = [[self.allSectors objectAtIndex:indexPath.row] valueForKey:@"SECTORNAME"];
            mainLabel.adjustsFontSizeToFitWidth = YES;
            mainLabel.numberOfLines = 4;
            mainLabel.lineBreakMode = UILineBreakModeWordWrap;

            secondLabel.text = [[self.allSectors objectAtIndex:indexPath.row] valueForKey:@"SECTORPCT"];
            secondLabel.adjustsFontSizeToFitWidth = YES;
            secondLabel.numberOfLines = 4;
            secondLabel.lineBreakMode = UILineBreakModeWordWrap;

            break;
        case 2:

            mainLabel.text = [[self.themes objectAtIndex:indexPath.row] valueForKey:@"THEME_NAME"];
            mainLabel.adjustsFontSizeToFitWidth = YES;
            mainLabel.numberOfLines = 4;
            mainLabel.lineBreakMode = UILineBreakModeWordWrap;

            secondLabel.text = [[self.themes objectAtIndex:indexPath.row] valueForKey:@"THEMEPCT"];
            secondLabel.adjustsFontSizeToFitWidth = YES;
            secondLabel.numberOfLines = 4;
            secondLabel.lineBreakMode = UILineBreakModeWordWrap;

            break;

        default:
            break;
    }

    return cell;
}

Answer 1

这是因为这条线（无论如何你都需要）：

UITableViewCell *cell = [tv dequeueReusableCellWithIdentifier:CellIdentifier];

基本上因为单元格被重用，内容会保留在单元格中，因此您需要在dequeu之后清理该单元格，然后设置新的contentView。

这里特别发生的是，即使您正在重置secondLabel的文本，当您在此处设置变量时：

secondLabel = [[[UILabel alloc] initWithFrame:CGRectMake(160,0,160,42)] autorelease];

创建的最后一个单元格是secondLabel始终指向的单元格，因此您实际上总是在更改相同的标签，因此我建议这样的内容：

UILabel *lblCell;
for (id label in [cell.contentView subviews]) {
            if ([label isKindOfClass:[UILabel class]]) {
                lblCell = label;
            }
        }

lblCell.text = [[self.themes objectAtIndex:indexPath.row] valueForKey:@"THEMEPCT"];

希望有所帮助。

为什么UITableViewCell在单个单元格中改变它们的值？

1 个答案: