Change UITableviewCell height dynamically in iPhon

问题:

I have three custom UILabel in UITableViewCell. The cell design like this,

Date(12.1.2012)  Time(12.00pm)
Cost: $20.00
Details

I have specified the row height 100 in - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath;. But, now the details some times return empty(Null) from the server. On that time i need to remove the Details label from the cell and change the particular cell(row) height to 70. How can i do this? I searched my level best in Google. But, i still just confused to do this. Can you please help me? Thanks. I got some idea from this link - http://www.cimgf.com/2009/09/23/uitableviewcell-dynamic-height/. They used only one label to resize the row height. Please help me.

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{ 
  return 90;
}

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

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


            UILabel *dateLabel = [[UILabel alloc] initWithFrame:CGRectMake(10, 0, 100, 30)];
            dateLabel.tag = 100;
            dateLabel.backgroundColor = [UIColor clearColor];
            dateLabel.font = [UIFont fontWithName:@"Helvetica" size:16];
            dateLabel.font = [UIFont boldSystemFontOfSize:16];
            dateLabel.highlightedTextColor = [UIColor whiteColor];
            [cell.contentView addSubview: dateLabel]; 

            UILabel *timeLabel = [[UILabel alloc] initWithFrame:CGRectMake(120, 0, 200, 25)];
            timeLabel.tag = 101;
            timeLabel.backgroundColor = [UIColor clearColor];
            timeLabel.font = [UIFont fontWithName:@"Helvetica" size:14];
            timeLabel.highlightedTextColor = [UIColor whiteColor];
            [cell.contentView addSubview: timeLabel]; 

            UILabel *costLabel = [[UILabel alloc] initWithFrame:CGRectMake(10, 30, 300, 25)];
            costLabel.tag = 102;
            costLabel.backgroundColor = [UIColor clearColor];
            costLabel.font = [UIFont fontWithName:@"Helvetica" size:14];
            costLabel.font = [UIFont boldSystemFontOfSize:14];
            costLabel.highlightedTextColor = [UIColor whiteColor];
            [cell.contentView addSubview: costLabel];

            UILabel *eventLabel = [[UILabel alloc] initWithFrame:CGRectMake(10, 60, 300, 25)];
            eventLabel.tag = 103;
            eventLabel.backgroundColor = [UIColor clearColor];
            eventLabel.font = [UIFont fontWithName:@"Helvetica" size:14];
            eventLabel.font = [UIFont boldSystemFontOfSize:14];
            eventLabel.highlightedTextColor = [UIColor whiteColor];
            [cell.contentView addSubview: eventLabel];
         }

        UILabel *dateLabel = (UILabel *) [cell.contentView viewWithTag:100];
        dateLabel.text = [DateArray objectAtIndex:indexPath.row];

        UILabel * timeLabel = (UILabel *) [cell.contentView viewWithTag:101];
        timeLabel.text = [timeArray objectAtIndex:indexPath.row];

        UILabel * costLabel = (UILabel *) [cell.contentView viewWithTag:102];
        costLabel.text = [costArray objectAtIndex:indexPath.row];

        UILabel *eventLabel = (UILabel *) [cell.contentView viewWithTag:103];
        NSString *description = [eventArray objectAtIndex:indexPath.row];
        if([description isEqualToString:@""])
       {
         eventLabel.text = @""; // Here i don't want to show this label and resize(reduce) the row height to 60;
       }
       else
       {
         eventLabel.text = description;
       }
        return cell;
    }

How can i do this? Thanks.

回答1:

While returning the height,check if the detail description is empty. If it is return 60.

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{ 
NSString *description = [eventArray objectAtIndex:indexPath.row];
if([description isEqualToString:@""])
    return 60
else
{
    return 90;
}
}

Also, you need to remove the label with @"Details" in the same if statement in cellForRowAtIndexPath:. Tag it beforehand, identify it from the subviews and remove it from the cell.

回答2:

You can check size of return string by using CGSize like this -

CGSize size = [detailStr sizeWithFont:[UIFont boldSystemFontOfSize:12.0f] constrainedToSize:CGSizeMake(190, 40) lineBreakMode:UILineBreakModeWordWrap];

you can change width, height and font according to your condition. Also please check if detailStr is not equal to nil before calculating size.