I have a UILabel that can be varying lengths depending on whether or not my app is running in portrait or landscape mode on an iPhone or iPad. When the text is too long to show on one line and it truncates I want the user to be able to press it and get a popup of the full text.
How can I check to see if the UILabel is truncating the text? Is it even possible? Right now I'm just checking for different lengths based on what mode I'm in but it does not work super well.
You can calculate the width of the string and see if the width is greater than label.bounds.size.width
NSString UIKit Additions has several methods for computing the size of the string with a specific font. However, if you have a minimumFontSize for your label that allows the system to shrink the text down to that size. You may want to use sizeWithFont:minFontSize:actualFontSize:forWidth:lineBreakMode: in that case.
CGSize size = [label.text sizeWithAttributes:@{NSFontAttributeName:label.font}];
if (size.width > label.bounds.size.width) {
...
}
Swift (as extension) - works for multi line uilabel:
swift4: (attributes param of boundingRect changed slightly)
extension UILabel {
var isTruncated: Bool {
guard let labelText = text else {
return false
}
let labelTextSize = (labelText as NSString).boundingRect(
with: CGSize(width: frame.size.width, height: .greatestFiniteMagnitude),
options: .usesLineFragmentOrigin,
attributes: [.font: font],
context: nil).size
return labelTextSize.height > bounds.size.height
}
}
swift3:
extension UILabel {
var isTruncated: Bool {
guard let labelText = text else {
return false
}
let labelTextSize = (labelText as NSString).boundingRect(
with: CGSize(width: frame.size.width, height: .greatestFiniteMagnitude),
options: .usesLineFragmentOrigin,
attributes: [NSFontAttributeName: font],
context: nil).size
return labelTextSize.height > bounds.size.height
}
}
swift2:
extension UILabel {
func isTruncated() -> Bool {
if let string = self.text {
let size: CGSize = (string as NSString).boundingRectWithSize(
CGSize(width: self.frame.size.width, height: CGFloat(FLT_MAX)),
options: NSStringDrawingOptions.UsesLineFragmentOrigin,
attributes: [NSFontAttributeName: self.font],
context: nil).size
if (size.height > self.bounds.size.height) {
return true
}
}
return false
}
}
EDIT: I just saw my answer was upvoted, but the code snippet I gave is deprecated.
Now the best way to do this is (ARC) :
NSMutableParagraphStyle *paragraph = [[NSMutableParagraphStyle alloc] init];
paragraph.lineBreakMode = mylabel.lineBreakMode;
NSDictionary *attributes = @{NSFontAttributeName : mylabel.font,
NSParagraphStyleAttributeName : paragraph};
CGSize constrainedSize = CGSizeMake(mylabel.bounds.size.width, NSIntegerMax);
CGRect rect = [mylabel.text boundingRectWithSize:constrainedSize
options:(NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading)
attributes:attributes context:nil];
if (rect.size.height > mylabel.bounds.size.height) {
NSLog(@"TOO MUCH");
}
Note the calculated size is not integer value. So if you do things like int height = rect.size.height, you will lose some floating point precision and may have wrong results.
Old answer (deprecated) :
If your label is multiline, you can use this code :
CGSize perfectSize = [mylabel.text sizeWithFont:mylabel.font constrainedToSize:CGSizeMake(mylabel.bounds.size.width, NSIntegerMax) lineBreakMode:mylabel.lineBreakMode];
if (perfectSize.height > mylabel.bounds.size.height) {
NSLog(@"TOO MUCH");
}
you can make a category with UILabel
- (BOOL)isTextTruncated
{
CGRect testBounds = self.bounds;
testBounds.size.height = NSIntegerMax;
CGRect limitActual = [self textRectForBounds:[self bounds] limitedToNumberOfLines:self.numberOfLines];
CGRect limitTest = [self textRectForBounds:testBounds limitedToNumberOfLines:self.numberOfLines + 1];
return limitTest.size.height>limitActual.size.height;
}
Use this category to find if a label is truncated on iOS 7 and above.
// UILabel+Truncation.h
@interface UILabel (Truncation)
@property (nonatomic, readonly) BOOL isTruncated;
@end
// UILabel+Truncation.m
@implementation UILabel (Truncation)
- (BOOL)isTruncated
{
CGSize sizeOfText =
[self.text boundingRectWithSize:CGSizeMake(self.bounds.size.width, CGFLOAT_MAX)
options:(NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading)
attributes:@{ NSFontAttributeName : label.font }
context: nil].size;
if (self.frame.size.height < ceilf(sizeOfText.height))
{
return YES;
}
return NO;
}
@end
To add to iDev 's answer, you should use intrinsicContentSize instead of frame, to make it works for Autolayout
- (BOOL)isTruncated:(UILabel *)label{
CGSize sizeOfText = [label.text boundingRectWithSize: CGSizeMake(label.intrinsicContentSize.width, CGFLOAT_MAX)
options: (NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading)
attributes: [NSDictionary dictionaryWithObject:label.font forKey:NSFontAttributeName] context: nil].size;
if (self.intrinsicContentSize.height < ceilf(sizeOfText.height)) {
return YES;
}
return NO;
}
Swift 3
You can count the number of lines after assigning the string and compare to the max number of lines of the label.
import Foundation
import UIKit
extension UILabel {
func countLabelLines() -> Int {
// Call self.layoutIfNeeded() if your view is uses auto layout
let myText = self.text! as NSString
let attributes = [NSFontAttributeName : self.font]
let labelSize = myText.boundingRect(with: CGSize(width: self.bounds.width, height: CGFloat.greatestFiniteMagnitude), options: NSStringDrawingOptions.usesLineFragmentOrigin, attributes: attributes, context: nil)
return Int(ceil(CGFloat(labelSize.height) / self.font.lineHeight))
}
func isTruncated() -> Bool {
if (self.countLabelLines() > self.numberOfLines) {
return true
}
return false
}
}
This works for iOS 8:
CGSize size = [label.text boundingRectWithSize:CGSizeMake(label.bounds.size.width, NSIntegerMax) options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName : label.font} context:nil].size;
if (size.height > label.frame.size.height) {
NSLog(@"truncated");
}
I have written a category for working with UILabel's truncation. Works on iOS 7 and later. Hope it helps ! uilabel tail truncation
@implementation UILabel (Truncation)
- (NSRange)truncatedRange
{
NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:[self attributedText]];
NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init];
[textStorage addLayoutManager:layoutManager];
NSTextContainer *textContainer = [[NSTextContainer alloc] initWithSize:[self bounds].size];
textContainer.lineFragmentPadding = 0;
[layoutManager addTextContainer:textContainer];
NSRange truncatedrange = [layoutManager truncatedGlyphRangeInLineFragmentForGlyphAtIndex:0];
return truncatedrange;
}
- (BOOL)isTruncated
{
return [self truncatedRange].location != NSNotFound;
}
- (NSString *)truncatedText
{
NSRange truncatedrange = [self truncatedRange];
if (truncatedrange.location != NSNotFound)
{
return [self.text substringWithRange:truncatedrange];
}
return nil;
}
@end
This is it. This works with attributedText, before falling back to plain text, which makes a lot of sense for us folks who deal with multiple font families, sizes, and even NSTextAttachments!
Works fine with autolayout, but obviously the constraints must be defined and set before we check isTruncated, otherwise the label itself wont even know how to lay itself out, so no way it would even know if its truncated.
It doesnt work to approach this problem with just a plain NSString and sizeThatFits. Im not sure how people were getting positive results like that. BTW, as mentioned numerous times, using sizeThatFits is not ideal at all because it takes into account numberOfLines for the resulting size, which defeats the whole purpose of what we are trying to do, because isTruncated would always return false regardless if its truncated or not.
extension UILabel {
var isTruncated: Bool {
layoutIfNeeded()
let rectBounds = CGSize(width: bounds.width, height: .greatestFiniteMagnitude)
var fullTextHeight: CGFloat?
if attributedText != nil {
fullTextHeight = attributedText?.boundingRect(with: rectBounds, options: .usesLineFragmentOrigin, context: nil).size.height
} else {
fullTextHeight = text?.boundingRect(with: rectBounds, options: .usesLineFragmentOrigin, attributes: [NSAttributedString.Key.font: font], context: nil).size.height
}
return (fullTextHeight ?? 0) > bounds.size.height
}
}
To add to what @iDev did, I modified the self.frame.size.height to use label.frame.size.height and also did not use NSStringDrawingUsesLineFontLeading. After those modifications, I achieved perfect calculation of when the truncation would happen (at least for my case).
- (BOOL)isTruncated:(UILabel *)label {
CGSize sizeOfText = [label.text boundingRectWithSize: CGSizeMake(label.bounds.size.width, CGFLOAT_MAX)
options: (NSStringDrawingUsesLineFragmentOrigin)
attributes: [NSDictionary dictionaryWithObject:label.font forKey:NSFontAttributeName] context: nil].size;
if (label.frame.size.height < ceilf(sizeOfText.height)) {
return YES;
}
return NO;
}
Here's the selected answer in Swift 3 (as an extension). The OP was asking about 1 line labels. Many of the swift answers I tried here are specific to multi-line labels and aren't flagging correctly on single line labels.
extension UILabel {
var isTruncated: Bool {
guard let labelText = text as? NSString else {
return false
}
let size = labelText.size(attributes: [NSFontAttributeName: font])
return size.width > self.bounds.width
}
}
extension UILabel {
public func resizeIfNeeded() -> CGFloat? {
guard let text = text, !text.isEmpty else { return nil }
if isTruncated() {
numberOfLines = 0
sizeToFit()
return frame.height
}
return nil
}
func isTruncated() -> Bool {
guard let text = text, !text.isEmpty else { return false }
let size: CGSize = text.size(withAttributes: [NSAttributedStringKey.font: font])
return size.width > self.bounds.size.width
}
}
You can calculate the width of the string and see if the width is greater than label width.
I had issues with boundingRect(with:options:attributes:context:) when using autolayout (to set a max height) and an attributed text with NSParagraph.lineSpacing
The spacing between lines was ignored (even when passed in attributes to the boundingRect method) so the label might be considered as not truncated when it was.
The solution I found is to use UIView.sizeThatFits :
extension UILabel {
var isTruncated: Bool {
layoutIfNeeded()
let heightThatFits = sizeThatFits(bounds.size).height
return heightThatFits > bounds.size.height
}
}
Because all the answers above use depreciated methods, i thought this could be useful:
- (BOOL)isLabelTruncated:(UILabel *)label
{
BOOL isTruncated = NO;
CGRect labelSize = [label.text boundingRectWithSize:CGSizeFromString(label.text) options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName : label.font} context:nil];
if (labelSize.size.width / labelSize.size.height > label.numberOfLines) {
isTruncated = YES;
}
return isTruncated;
}
To handle iOS 6 (yes, some of us still have to), here's yet another expansion to @iDev's answer. The key takeaway is that, for iOS 6, to make sure your UILabel's numberOfLines is set to 0 before calling sizeThatFits; if not, it'll give you a result that says "the points to draw numberOfLines worth of height" is needed to draw the label text.
- (BOOL)isTruncated
{
CGSize sizeOfText;
// iOS 7 & 8
if([self.text respondsToSelector:@selector(boundingRectWithSize:options:attributes:context:)])
{
sizeOfText = [self.text boundingRectWithSize:CGSizeMake(self.bounds.size.width,CGFLOAT_MAX)
options:(NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading)
attributes:@{NSFontAttributeName:self.font}
context:nil].size;
}
// iOS 6
else
{
// For iOS6, set numberOfLines to 0 (i.e. draw label text using as many lines as it takes)
// so that siteThatFits works correctly. If we leave it = 1 (for example), it'll come
// back telling us that we only need 1 line!
NSInteger origNumLines = self.numberOfLines;
self.numberOfLines = 0;
sizeOfText = [self sizeThatFits:CGSizeMake(self.bounds.size.width,CGFLOAT_MAX)];
self.numberOfLines = origNumLines;
}
return ((self.bounds.size.height < sizeOfText.height) ? YES : NO);
}
Swift 3 solution
I think the best solution is to (1) create a UILabel with the same properties as the label you're checking for truncation, (2) call .sizeToFit(), (3) compare the attributes of the dummy label with your actual label.
For example, if you want to check whether a one lined label that has varying width truncates or not, then you can use this extension:
extension UILabel {
func isTruncated() -> Bool {
let label = UILabel(frame: CGRect(x: 0, y: 0, width: CGFloat.greatestFiniteMagnitude, height: self.bounds.height))
label.numberOfLines = 1
label.font = self.font
label.text = self.text
label.sizeToFit()
if label.frame.width > self.frame.width {
return true
} else {
return false
}
}
}
...but again, you can easily modify the above code to fit your needs. So let's say your label is multilined and has varying height. Then the extension would look something like this:
extension UILabel {
func isTruncated() -> Bool {
let label = UILabel(frame: CGRect(x: 0, y: 0, width: self.bounds.width, height: CGFloat.greatestFiniteMagnitude))
label.numberOfLines = 0
label.font = self.font
label.text = self.text
label.sizeToFit()
if label.frame.height > self.frame.height {
return true
} else {
return false
}
}
}
Wouldnt it be easy to set the title attribute for the label , setting this will display full label when hovered.
you can calculate the length of the label and div width (convert to length - jQuery / Javascript - How do I convert a pixel value (20px) to a number value (20)).
set jquery to set title if length is greater than the div width.
var divlen = parseInt(jQuery("#yourdivid").width,10);
var lablen =jQuery("#yourlabelid").text().length;
if(lablen < divlen){
jQuery("#yourlabelid").attr("title",jQuery("#yourlabelid").text());
}
来源：https://stackoverflow.com/questions/3077109/how-to-check-if-uilabel-is-truncated