Comments on: Truncate a String and Append an Ellipsis, Respecting the Font Size

By: Jackson

Jackson — Wed, 18 Apr 2012 12:17:07 +0000

Thanks for posting your snazzy code. You saved me a good half hour.

By: Charton Sapinoso

Charton Sapinoso — Wed, 21 Mar 2012 00:42:16 +0000

Thanks John, this was so useful.

In my case, when we build projects we normally have this utility class. Instead of creating this new class, I added the methods above as a static (+) method
header file:

+ (NSString *)stringByTruncatingToWidth:(CGFloat)width withFont:(UIFont *)font withString:(NSString *)string;

implementation file:
+ (NSString *)stringByTruncatingToWidth:(CGFloat)width withFont:(UIFont *)font withString:(NSString *)string {
// Create copy that will be the returned result
NSMutableString *truncatedString = [[string mutableCopy] autorelease];

// Make sure string is longer than requested width
if ([string sizeWithFont:font].width > width)
{
// Accommodate for ellipsis we’ll tack on the end
width -= [ellipsis sizeWithFont:font].width;

// Get range for last character in string
NSRange range = {truncatedString.length – 1, 1};

// Loop, deleting characters until string fits within width
while ([truncatedString sizeWithFont:font].width > width)
{
// Delete character at end
[truncatedString deleteCharactersInRange:range];

// Move back another character
range.location–;
}

// Append ellipsis
[truncatedString replaceCharactersInRange:range withString:ellipsis];
}

return truncatedString;
}

usage:
[DeviceUtility stringByTruncatingToWidth:myTextLabel.frame.size.width withFont:myFont withString:myString];

Hope this helps someone too.

By: phait

phait — Tue, 25 Jan 2011 06:27:56 +0000

how would you do the same thing for multiple lines where the ellipsis is only added to the last line?

By: berec

berec — Wed, 10 Nov 2010 14:01:32 +0000

Hello. Thank you for that. Is there any way to truncate multiline text? I mean adding to your category method like – (NSString*)stringByTruncatingToSize:(CGSize)size withFont:(UIFont *)font; Is it possible?
Thanks in advance.

By: Krille

Krille — Tue, 27 Jul 2010 12:18:06 +0000

Great – thank you very much, everytime I learn something new from your articles!

By: John Muchow

John Muchow — Tue, 27 Jul 2010 12:01:00 +0000

Krille, thanks for pointing that out. I’ve updated the code to check for the string length up front.

By: Krille

Krille — Tue, 27 Jul 2010 10:10:18 +0000

Thank you for this post!
I have a problem with this implementation: Strings are cut, even if they are narrower
than the defined maximum width:

Example:
cell.textLabel.text = [news stringByTruncatingToWidth:240 withFont:[UIFont boldSystemFontOfSize:15]];

So every String is at least missing the last character and gets the ellipsis appended…

“Here is a superlong Title to…” -> correct
“Short Titl…” -> wrong

Cheers
Krille

By: John Muchow

John Muchow — Mon, 26 Jul 2010 14:27:52 +0000

Michelle, the docs state “If you are using managed memory (not garbage collection), this method retains the new object before returning it.” so the autorelease should do the trick…

By: Michelle

Michelle — Mon, 26 Jul 2010 14:20:48 +0000

Does NSString mutableCopy really return a string that needs to be released? By standard naming conventions, it should not.

You might want to generalize the string to be appended.

- (NSString*)stringByTruncatingStringToWidth:(CGFloat)width withFont:(UIFont *)font endingWith:(NSString*)endString { /* your implementation but using endString */ }

and implement your function as

- (NSString*)stringByTruncatingStringToWidth:(CGFloat)width withFont:(UIFont *)font
{
[self stringByTruncatingStringToWidth: width withFont: font endingWith: ellipsis];
}

But that’s just a small tweak.