Question

sizeWithFont:constrainedToSize:lineBreakMode: don’t seem to be returning me the correct width. After these codes are executed, I see that part of the string in the label is chopping off, which means I’ve to manually add a few pixels to the size. Am I missing something?

I’ve a UILabel:

theLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, LABELWIDTH, LABELHEIGHT)];
theLabel.lineBreakMode = UILineBreakModeWordWrap;
theLabel.numberOfLines = 0;
[theLabel setFont:[UIFont fontWithName:@"MarkerFelt-Wide" size:16]];
theLabel.textColor = [UIColor blackColor];
theLabel.textAlignment =  UITextAlignmentLeft;
theLabel.backgroundColor = [UIColor clearColor];

I tried to programmatically modify the size of the label using the following:

CGSize maximumLabelSize = CGSizeMake(LABELWIDTH, 10000);

CGSize expectedLabelSize = [someString sizeWithFont:theLabel.font constrainedToSize:maximumLabelSize lineBreakMode:theLabel.lineBreakMode];

theLabel.text = someString;

CGRect newFrame = theLabel.frame;
newFrame.size.height = expectedLabelSize.height;
newFrame.size.width = newFrame.size.width+50;
theLabel.frame = newFrame;

Answer 1

Ok, well, the first thing I’ll say is that there are some very useful ways to deal with frames that you currently aren’t employing. For example, your code,

CGRect newFrame = theLabel.frame;
newFrame.size.height = expectedLabelSize.height;
newFrame.size.width = newFrame.size.width+50;
theLabel.frame = newFrame;

Can be rewritten with functions from CGGeometry,

CGFloat widthOffset = 50.0f;
theLabel.frame = CGRectOffset(CGRectInset(theLabel.frame, widthOffset, 0.0f), widthOffset / 2.0f, 0.0f);

However, if your code worked as it was intended, you would not need to do this at all. You can go two routes,

[theLabel sizeToFit];

Or, this should also work,

theLabel.frame = CGRectMake(theLabel.frame.origin.x, theLabel.frame.origin.y, expectedLabelSize.width, expectedLabelSize.height);

No where in your earlier code did you change the width of theLabel to match the expected width. Notice, you wrote newFrame.size.width = newFrame.size.width+50 and that should be newFrame.size.width = expectedLabelSize.width.