Adjust UILabel height depending on the text

Question

Consider i have the following text in a UILabel (a long line of dynamic text):

Since the alien army vastly outnumbers the team, players must use the post-apocalyptic world to their advantage, such as seeking cover behind dumpsters, pillars, cars, rubble, and other objects.

I want to resize the UILabel's height so that the text can fit in. I'm using following properties of UILabel to make the text within to wrap.

myUILabel.lineBreakMode = UILineBreakModeWordWrap;
myUILabel.numberOfLines = 0;

Please let me know if i'm not heading in the right direction. Thanks.

Answer 1

You can implement TableViewController's (UITableViewCell *)tableView:cellForRowAtIndexPath method in the following way (for example) :

#define CELL_LABEL_TAG 1
- (UITableViewCell *)tableView:(UITableView *)tableView  cellForRowAtIndexPath:(NSIndexPath *)indexPath {

NSString *text = @"my long text";

static NSString *MyIdentifier = @"MyIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:MyIdentifier];
if (cell == nil) {
  cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero  reuseIdentifier:identifier] autorelease];


CGFloat width = [UIScreen mainScreen].bounds.size.width - 50;
CGFloat height = [self textHeight:text] + 10;
CGRect frame = CGRectMake(10.0f, 10.0f, width, height);

UILabel *cellLabel = [[UILabel alloc] initWithFrame:frame];
cellLabel.tag = CELL_LABEL_TAG;
cellLabel.textColor = [UIColor blackColor];
cellLabel.backgroundColor = [UIColor clearColor];
cellLabel.textAlignment = UITextAlignmentLeft;
cellLabel.font = [UIFont systemFontOfSize:12.0f];
[cell.contentView addSubview:cellLabel];
[cellLabel release];

return cell;

}
UILabel *label = (UILabel *)[cell viewWithTag:CELL_LABEL_TAG];
label.text = text;
label.numberOfLines = 0;
[label sizeToFit];
return cell;

Also use NSSTring's sizeWithFont:constrainedToSize:lineBreakMode: method to compute the text's height.

Answer 2

sizeWithFont constrainedToSize:lineBreakMode: is the method to use. An example of how to use it is below

//Calculate the expected size based on the font and linebreak mode of your label
CGSize maximumLabelSize = CGSizeMake(296,9999);

CGSize expectedLabelSize = [yourString sizeWithFont:yourLabel.font 
       constrainedToSize:maximumLabelSize 
       lineBreakMode:yourLabel.lineBreakMode]; 

//adjust the label the the new height.
CGRect newFrame = yourLabel.frame;
newFrame.size.height = expectedLabelSize.height;
yourLabel.frame = newFrame;

Hope this helps.

chris.

Answer 3

See also: http://stackoverflow.com/questions/406212/sizing-a-uilabel-in-the-iphone-sdk-to-fit

Answer 4

Finally, it worked. Thank you guys.

I was not getting it to work because i was trying to resize the label in heightForRowAtIndexPath method:

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath

... and (yeah silly me), i was resizing the label to default in cellForRowAtIndexPath method - i was overlooking the code i had written earlier:

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

Answer 5

Thanks for this post. It helped me a great deal. In my case I am also editing the text in a separate view controller. I noticed that when I use:

[cell.contentView addSubview:cellLabel];

in the tableView:cellForRowAtIndexPath: method that the label view was continually rendered over the top of the previous view each time I edited the cell. The text became pixelated, and when something was deleted or changed, the previous version was visible under the new version. Here's how I solved the problem:

if ([[cell.contentView subviews] count] > 0) {
    UIView *test = [[cell.contentView subviews] objectAtIndex:0];
    [test removeFromSuperview];
}
[cell.contentView insertSubview:cellLabel atIndex:0];

No more weird layering. If there is a better way to handle this, Please let me know.

Answer 6

One line is Chris's answer is wrong.

newFrame.size.height = maximumLabelSize.height;

should be

newFrame.size.height = expectedLabelSize.height;

Other than that, it's the correct solution.

Answer 7

You were going in the right direction. All you need to do is:

myUILabel.numberOfLines = 0;
myUILabel.text = @"Enter large amount of text here";
[myUILabel sizeToFit];