I want to get the Thumbnail Image of my PHAsset. I already extracted a PHAsset from the Photo Library and want to get the Thumbnail Image now.
Can you help me in Objective-C?
Thanks!
In case someone is looking for a swift solution, here is an extension:
extension PHAsset {
var thumbnailImage : UIImage {
get {
let manager = PHImageManager.default()
let option = PHImageRequestOptions()
var thumbnail = UIImage()
option.isSynchronous = true
manager.requestImage(for: self, targetSize: CGSize(width: 300, height: 300), contentMode: .aspectFit, options: option, resultHandler: {(result, info)->Void in
thumbnail = result!
})
return thumbnail
}
}
}
The PHImageManagerClass has the method:
- requestImageForAsset:targetSize:contentMode:options:resultHandler:
Here is a complete answer for Swift 4 showing the function & call against it. Also, make sure you have the photos privacy flag set in your plist.
import Photos
func requestImage(for asset: PHAsset,
targetSize: CGSize,
contentMode: PHImageContentMode,
completionHandler: #escaping (UIImage?) -> ()) {
let imageManager = PHImageManager()
imageManager.requestImage(for: asset,
targetSize: targetSize,
contentMode: contentMode,
options: nil) { (image, _) in
completionHandler(image)
}
}
let asset = // your existing PHAsset
let targetSize = CGSize(width: 100, height: 100)
let contentModel = PHImageContentMode.aspectFit
requestImage(for: asset, targetSize: targetSize, contentMode: contentModel, completionHandler: { image in
// Do something with your image if it exists
})
PHImageRequestOptions *options = [[PHImageRequestOptions alloc] init];
options.resizeMode = PHImageRequestOptionsResizeModeExact;
NSInteger retinaMultiplier = [UIScreen mainScreen].scale;
CGSize retinaSquare = CGSizeMake(imageView.bounds.size.width * retinaMultiplier, imageView.bounds.size.height * retinaMultiplier);
[[PHImageManager defaultManager]
requestImageForAsset:(PHAsset *)_asset
targetSize:retinaSquare
contentMode:PHImageContentModeAspectFill
options:options
resultHandler:^(UIImage *result, NSDictionary *info) {
imageView.image =[UIImage imageWithCGImage:result.CGImage scale:retinaMultiplier orientation:result.imageOrientation];
}];
i get this answer from How to fetch squared thumbnails from PHImageManager?
Related
How can I get the size(height/width) of an image from URL in objective-C? I want my container size according to the image. I am using AFNetworking 3.0.
I could use SDWebImage if it fulfills my requirement.
Knowing the size of an image before actually loading it can be necessary in a number of cases. For example, setting the height of a tableView cell in the heightForRowAtIndexPath method while loading the actual image later in the cellForRowAtIndexPath (this is a very frequent catch 22).
One simple way to do it, is to read the image header from the server URL using the Image I/O interface:
#import <ImageIO/ImageIO.h>
NSMutableString *imageURL = [NSMutableString stringWithFormat:#"http://www.myimageurl.com/image.png"];
CGImageSourceRef source = CGImageSourceCreateWithURL((CFURLRef)[NSURL URLWithString:imageURL], NULL);
NSDictionary* imageHeader = (__bridge NSDictionary*) CGImageSourceCopyPropertiesAtIndex(source, 0, NULL);
NSLog(#"Image header %#",imageHeader);
NSLog(#"PixelHeight %#",[imageHeader objectForKey:#"PixelHeight"]);
Swift 4.x
Xcode 12.x
func sizeOfImageAt(url: URL) -> CGSize? {
// with CGImageSource we avoid loading the whole image into memory
guard let source = CGImageSourceCreateWithURL(url as CFURL, nil) else {
return nil
}
let propertiesOptions = [kCGImageSourceShouldCache: false] as CFDictionary
guard let properties = CGImageSourceCopyPropertiesAtIndex(source, 0, propertiesOptions) as? [CFString: Any] else {
return nil
}
if let width = properties[kCGImagePropertyPixelWidth] as? CGFloat,
let height = properties[kCGImagePropertyPixelHeight] as? CGFloat {
return CGSize(width: width, height: height)
} else {
return nil
}
}
Use Asynchronous mechanism called GCD in iOS to dowload image without affecting your main thread.
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
// Download IMAGE using URL
NSData *data = [[NSData alloc]initWithContentsOfURL:URL];
// COMPOSE IMAGE FROM NSData
UIImage *image = [[UIImage alloc]initWithData:data];
dispatch_async(dispatch_get_main_queue(), ^{
// UI UPDATION ON MAIN THREAD
// Calcualte height & width of image
CGFloat height = image.size.height;
CGFloat width = image.size.width;
});
});
For Swift 4 use this:
let imageURL = URL(string: post.imageBigPath)!
let source = CGImageSourceCreateWithURL(imageURL as CFURL,
let imageHeader = CGImageSourceCopyPropertiesAtIndex(source!, 0, nil)! as NSDictionary;
print("Image header: \(imageHeader)")
The header would looks like:
Image header: {
ColorModel = RGB;
Depth = 8;
PixelHeight = 640;
PixelWidth = 640;
"{Exif}" = {
PixelXDimension = 360;
PixelYDimension = 360;
};
"{JFIF}" = {
DensityUnit = 0;
JFIFVersion = (
1,
0,
1
);
XDensity = 72;
YDensity = 72;
};
"{TIFF}" = {
Orientation = 0;
}; }
So u can get from it the Width, Height.
you can try like this:
NSData *data = [[NSData alloc]initWithContentsOfURL:URL];
UIImage *image = [[UIImage alloc]initWithData:data];
CGFloat height = image.size.height;
CGFloat width = image.size.width;
I have implemented an AVPlayer and i want to take an image or thumbnail when clicking on a toolbar button and open in a new UIViewController with UIImageView. The image should be scaled exactly like the AVPlayer.
The segue is already working, i just have to implement that i get the image at the current play time.
Thanks!
Objective-C
AVAsset *asset = [AVAsset assetWithURL:sourceURL];
AVAssetImageGenerator *imageGenerator = [[AVAssetImageGenerator alloc]initWithAsset:asset];
CMTime time = CMTimeMake(1, 1);
CGImageRef imageRef = [imageGenerator copyCGImageAtTime:time actualTime:NULL error:NULL];
UIImage *thumbnail = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef); // CGImageRef won't be released by ARC
Swift
var asset = AVAsset.assetWithURL(sourceURL)
var imageGenerator = AVAssetImageGenerator(asset: asset!)
var time = CMTimeMake(1, 1)
var imageRef = try! imageGenerator!.copyCGImageAtTime(time, actualTime: nil)
var thumbnail = UIImage.imageWithCGImage(imageRef)
CGImageRelease(imageRef) // CGImageRef won't be released by ARC
Swift 3.0
var sourceURL = URL(string: "Your Asset URL")
var asset = AVAsset(url: sourceURL!)
var imageGenerator = AVAssetImageGenerator(asset: asset)
var time = CMTimeMake(1, 1)
var imageRef = try! imageGenerator.copyCGImage(at: time, actualTime: nil)
var thumbnail = UIImage(cgImage:imageRef)
Note : Interpret Swift code according to your swift version.
Try this
- (UIImage*)takeScreeenShot {
AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:vidURL
options:nil];
AVAssetImageGenerator *imageGenerator = [[AVAssetImageGenerator alloc] initWithAsset:asset];
imageGenerator.appliesPreferredTrackTransform = YES;
NSError *err = NULL;
CMTime time = CMTimeMake(1, 60); // time range in which you want
screenshot
CGImageRef imgRef = [imageGenerator copyCGImageAtTime:time actualTime:NULL
error:&err];
return [[UIImage alloc] initWithCGImage:imgRef];
}
Hope this helps !!!
Swift 2.x:
let asset = AVAsset(...)
let imageGenerator = AVAssetImageGenerator(asset: asset)
let screenshotTime = CMTime(seconds: 1, preferredTimescale: 1)
if let imageRef = try? imageGenerator.copyCGImageAtTime(screenshotTime, actualTime: nil) {
let image = UIImage(CGImage: imageRef)
// do something with your image
}
Add below code to generate thumbnail from video.
AVURLAsset *assetURL = [[AVURLAsset alloc] initWithURL:partOneUrl options:nil];
AVAssetImageGenerator *assetGenerator = [[AVAssetImageGenerator alloc] initWithAsset:assetURL];
assetGenerator.appliesPreferredTrackTransform = YES;
NSError *err = NULL;
CMTime time = CMTimeMake(1, 2);
CGImageRef imgRef = [assetGenerator copyCGImageAtTime:time actualTime:NULL error:&err];
UIImage *one = [[UIImage alloc] initWithCGImage:imgRef];
This is how I get a shot of the current visible frame on the scene in Swift:
The key is to
get the current time of the player which is of type CMTime
convert that time into seconds of type Float64
switch the secondss back to CMTime using CMTimeMake. The first parameter which would be where the seconds goes should be cast to Int64
Code:
var myImage: UIImage?
guard let player = player else { return }
let currentTime: CMTime = player.currentTime() // step 1.
let currentTimeInSecs: Float64 = CMTimeGetSeconds(currentTime) // step 2.
let actionTime: CMTime = CMTimeMake(Int64(currentTimeInSecs), 1) // step 3.
let asset = AVAsset(url: fileUrl)
let imageGenerator = AVAssetImageGenerator(asset: asset)
imageGenerator.appliesPreferredTrackTransform = true // prevent image rotation
do{
let imageRef = try imageGenerator.copyCGImage(at: actionTime, actualTime: nil)
myImage = UIImage(cgImage: imageRef)
}catch let err as NSError{
print(err.localizedDescription)
}
Swift extension for generating thumbnails from video
extension AVPlayer {
func generateThumbnail(time: CMTime) -> UIImage? {
guard let asset = currentItem?.asset else { return nil }
let imageGenerator = AVAssetImageGenerator(asset: asset)
do {
let cgImage = try imageGenerator.copyCGImage(at: time, actualTime: nil)
return UIImage(cgImage: cgImage)
} catch {
print(error.localizedDescription)
}
return nil
}
}
When you need to create multiple thumbnails at once the class AVAssetImageGenerator is golden, as it provides an async way.
If you need a Thumbnail-Image of the player's current frame, simply render it's View (platform specific) or its Layer (platform independent):
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGSize frameSize = _playerLayer.frame.size;
CGContextRef thumbnailContext = CGBitmapContextCreate(nil, frameSize.width, frameSize.height, 8, 0, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst);
CGColorSpaceRelease(colorSpace);
[_playerLayer renderInContext:thumbnailContext];
CGImageRef playerThumbnail = CGBitmapContextCreateImage(thumbnailContext);
CGContextRelease(thumbnailContext);
This is super fast and works synchronously.
Code for 2022:
seconds = .. the normal human-meaning desired time position in the video
guard let pl = .. your player ..
guard let ite = pl.currentItem ..
let testGen = AVAssetImageGenerator(asset: ite.asset)
testGen.maximumSize = CGSize(width: 0, height: .. height of your preview box)
testGen.requestedTimeToleranceBefore = .zero // during development
// or something like ... CMTime(value: .. your tolerance .., timescale: 600)
testGen.requestedTimeToleranceAfter = .zero // during development
// ditto
if #available(tvOS 16, *) {
Task { [weak self] ..
do {
let ct = CMTime(value: CMTimeValue(seconds), timescale: 1)
// NOTE THE "1"
let (foundImage, foundTime) = try await testGen.image(at: ct)
let foundAsSecs = CMTimeGetSeconds(foundTime)
print("tried gen at \(seconds) found as \(foundAsSecs) \n")
self. .. your preview .image = UIImage(cgImage: foundImage)
} catch {
print("gen err \(error)")
}
}
}
Setting the two tolerances is a sophisticated issue, google.
Watch out for the gotchya where timescale of 1 is needed for the CMTime.
I'm having a hard figuring out how to programmatically retrieve the most recent photo in the camera roll without user intervention. To be clear, I do not want to use an Image Picker, I want the app to automatically grab the newest photo when the app opens.
I know this is possible because Ive seen a similar app do it, but I cant seem to find any info on it.
One way is to use AssetsLibrary and use n - 1 as the index for enumeration.
ALAssetsLibrary *assetsLibrary = [[ALAssetsLibrary alloc] init];
[assetsLibrary enumerateGroupsWithTypes:ALAssetsGroupSavedPhotos
usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
if (nil != group) {
// be sure to filter the group so you only get photos
[group setAssetsFilter:[ALAssetsFilter allPhotos]];
if (group.numberOfAssets > 0) {
[group enumerateAssetsAtIndexes:[NSIndexSet indexSetWithIndex:group.numberOfAssets - 1]
options:0
usingBlock:^(ALAsset *result, NSUInteger index, BOOL *stop) {
if (nil != result) {
ALAssetRepresentation *repr = [result defaultRepresentation];
// this is the most recent saved photo
UIImage *img = [UIImage imageWithCGImage:[repr fullResolutionImage]];
// we only need the first (most recent) photo -- stop the enumeration
*stop = YES;
}
}];
}
}
*stop = NO;
} failureBlock:^(NSError *error) {
NSLog(#"error: %#", error);
}];
Instead of messing with the index, you can enumerate through the list in reverse. This pattern works well if you want the most recent image or if you want to list the images in a UICollectionView with the most recent image first.
Example to return the most recent image:
[group enumerateAssetsWithOptions:NSEnumerationReverse usingBlock:^(ALAsset *asset, NSUInteger index, BOOL *stop) {
if (asset) {
ALAssetRepresentation *repr = [asset defaultRepresentation];
UIImage *img = [UIImage imageWithCGImage:[repr fullResolutionImage]];
*stop = YES;
}
}];
In iOS 8, Apple added the Photos library which makes for easier querying. In iOS 9, ALAssetLibrary is deprecated.
Here's some Swift code to get the most recent photo taken with that framework.
import UIKit
import Photos
struct LastPhotoRetriever {
func queryLastPhoto(resizeTo size: CGSize?, queryCallback: (UIImage? -> Void)) {
let fetchOptions = PHFetchOptions()
fetchOptions.sortDescriptors = [NSSortDescriptor(key: "creationDate", ascending: false)]
// fetchOptions.fetchLimit = 1 // This is available in iOS 9.
if let fetchResult = PHAsset.fetchAssetsWithMediaType(PHAssetMediaType.Image, options: fetchOptions) {
if let asset = fetchResult.firstObject as? PHAsset {
let manager = PHImageManager.defaultManager()
// If you already know how you want to resize,
// great, otherwise, use full-size.
let targetSize = size == nil ? CGSize(width: asset.pixelWidth, height: asset.pixelHeight) : size!
// I arbitrarily chose AspectFit here. AspectFill is
// also available.
manager.requestImageForAsset(asset,
targetSize: targetSize,
contentMode: .AspectFit,
options: nil,
resultHandler: { image, info in
queryCallback(image)
})
}
}
}
}
Swift 3.0:
1) Import Photos framework in your header before your class declaration.
import Photos
2) Add the following method, which returns the last image.
func queryLastPhoto(resizeTo size: CGSize?, queryCallback: #escaping ((UIImage?) -> Void)) {
let fetchOptions = PHFetchOptions()
fetchOptions.sortDescriptors = [NSSortDescriptor(key: "creationDate", ascending: false)]
let requestOptions = PHImageRequestOptions()
requestOptions.isSynchronous = true
let fetchResult = PHAsset.fetchAssets(with: PHAssetMediaType.image, options: fetchOptions)
if let asset = fetchResult.firstObject {
let manager = PHImageManager.default()
let targetSize = size == nil ? CGSize(width: asset.pixelWidth, height: asset.pixelHeight) : size!
manager.requestImage(for: asset,
targetSize: targetSize,
contentMode: .aspectFit,
options: requestOptions,
resultHandler: { image, info in
queryCallback(image)
})
}
}
3) Then call this method somewhere in your app (maybe a button action):
#IBAction func pressedLastPictureAttachmentButton(_ sender: Any) {
queryLastPhoto(resizeTo: nil){
image in
print(image)
}
}
To add to Art Gillespie's answer, using the fullResolutionImage uses the original image which — depending on the device's orientation when taking the photo — could leave you with an upside down, or -90° image.
To get the modified, but optimised image for this, use fullScreenImage instead....
UIImage *img = [UIImage imageWithCGImage:[repr fullScreenImage]];
Answer to the question (in Swift):
func pickingTheLastImageFromThePhotoLibrary() {
let assetsLibrary: ALAssetsLibrary = ALAssetsLibrary()
assetsLibrary.enumerateGroupsWithTypes(ALAssetsGroupSavedPhotos,
usingBlock: { (let group: ALAssetsGroup!, var stop: UnsafeMutablePointer<ObjCBool>) -> Void in
if (group != nil) {
// Be sure to filter the group so you only get photos
group.setAssetsFilter(ALAssetsFilter.allPhotos())
group.enumerateAssetsWithOptions(NSEnumerationOptions.Reverse,
usingBlock: { (let asset: ALAsset!,
let index: Int,
var stop: UnsafeMutablePointer<ObjCBool>)
-> Void in
if(asset != nil) {
/*
Returns a CGImage representation of the asset.
Using the fullResolutionImage uses the original image which — depending on the
device's orientation when taking the photo — could leave you with an upside down,
or -90° image. To get the modified, but optimised image for this, use
fullScreenImage instead.
*/
// let myCGImage: CGImage! = asset.defaultRepresentation().fullResolutionImage().takeUnretainedValue()
/*
Returns a CGImage of the representation that is appropriate for displaying full
screen.
*/
// let myCGImage: CGImage! = asset.defaultRepresentation().fullScreenImage().takeUnretainedValue()
/* Returns a thumbnail representation of the asset. */
let myCGImage: CGImage! = asset.thumbnail().takeUnretainedValue()
// Here we set the image included in the UIImageView
self.myUIImageView.image = UIImage(CGImage: myCGImage)
stop.memory = ObjCBool(true)
}
})
}
stop.memory = ObjCBool(false)
})
{ (let error: NSError!) -> Void in
println("A problem occurred: \(error.localizedDescription)")
}
}
Using Photos Library ( Objective-C )
PHFetchOptions *fetchOptions = [[PHFetchOptions alloc] init];
fetchOptions.sortDescriptors = #[[NSSortDescriptor sortDescriptorWithKey:#"creationDate" ascending:NO]];
PHFetchResult *assetsFetchResult = [PHAsset fetchAssetsInAssetCollection:assetCollection options:fetchOptions];
if (assetsFetchResult.count>0) {
PHAsset *asset = [assetsFetchResult objectAtIndex:0];
CGFloat scale = [UIScreen mainScreen].scale;
CGFloat dimension = 55.0f; // set your required size
CGSize size = CGSizeMake(dimension*scale, dimension*scale);
[[PHImageManager defaultManager] requestImageForAsset:asset
targetSize:size
contentMode:PHImageContentModeAspectFit
options:nil
resultHandler:^(UIImage *result, NSDictionary *info) {
// do your thing with the image
}
];
}
Is there any way to get the quick look preview image for a file?
I'm looking for something like this:
NSImage *image = [QuickLookPreviewer quickLookPreviewForFile:path];
See QLThumbnailRequest in the docs: https://developer.apple.com/library/mac/#documentation/UserExperience/Reference/QLThumbnailRequest_Ref/Reference/reference.html
NSURL *path = aFileUrl;
NSDictionary *options = [NSDictionary dictionaryWithObject:[NSNumber numberWithBool:NO] forKey:(NSString *)kQLThumbnailOptionIconModeKey];
CGImageRef ref = QLThumbnailImageCreate(kCFAllocatorDefault, (CFURLRef)path, CGSizeMake(600, 800 /* Or whatever size you want */), (CFDictionaryRef)options);
In Swift I ended up with something like this (the force unwraps should be replaced):
let options = [
kQLThumbnailOptionIconModeKey: false
]
let ref = QLThumbnailCreate(
kCFAllocatorDefault,
url as NSURL,
CGSize(width: 150, height: 150),
options as CFDictionary
)
let thumbnail = ref!.takeRetainedValue()
let cgImageRef = QLThumbnailCopyImage(thumbnail)
let cgImage = cgImageRef!.takeRetainedValue()
let image = NSImage(cgImage: cgImage, size: CGSize(width: cgImage.width, height: cgImage.height))
Is it possible to reduce the gap between text, when put in multiple lines in a UILabel? We can set the frame, font size and number of lines. I want to reduce the gap between the two lines in that label.
In Xcode 6 you can do this in the storyboard:
I thought about adding something new to this answer, so I don't feel as bad... Here is a Swift answer:
import Cocoa
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = 40
let attrString = NSMutableAttributedString(string: "Swift Answer")
attrString.addAttribute(.paragraphStyle, value:paragraphStyle, range:NSMakeRange(0, attrString.length))
var tableViewCell = NSTableCellView()
tableViewCell.textField.attributedStringValue = attrString
"Short answer: you can't. To change the spacing between lines of text, you will have to subclass UILabel and roll your own drawTextInRect, or create multiple labels."
See: Set UILabel line spacing
This is a really old answer, and other have already addded the new and better way to handle this.. Please see the up to date answers provided below.
Starting from iOS 6 you can set an attributed string to the UILabel. Check the following :
NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:label.text];
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.lineSpacing = spacing;
[attributedString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, label.text.length)];
label.attributedText = attributedString;
The solutions stated here didn't work for me. I found a slightly different way to do it with the iOS 6 NSAttributeString:
myLabel.numberOfLines = 0;
NSString* string = #"String with line one. \n Line two. \n Line three.";
NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc] init];
style.minimumLineHeight = 30.f;
style.maximumLineHeight = 30.f;
NSDictionary *attributtes = #{NSParagraphStyleAttributeName : style,};
myLabel.attributedText = [[NSAttributedString alloc] initWithString:string
attributes:attributtes];
[myLabel sizeToFit];
From Interface Builder (Storyboard/XIB):
Programmatically:
SWift 4
Using label extension
extension UILabel {
// Pass value for any one of both parameters and see result
func setLineSpacing(lineSpacing: CGFloat = 0.0, lineHeightMultiple: CGFloat = 0.0) {
guard let labelText = self.text else { return }
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = lineSpacing
paragraphStyle.lineHeightMultiple = lineHeightMultiple
let attributedString:NSMutableAttributedString
if let labelattributedText = self.attributedText {
attributedString = NSMutableAttributedString(attributedString: labelattributedText)
} else {
attributedString = NSMutableAttributedString(string: labelText)
}
// Line spacing attribute
attributedString.addAttribute(NSAttributedStringKey.paragraphStyle, value:paragraphStyle, range:NSMakeRange(0, attributedString.length))
self.attributedText = attributedString
}
}
Now call extension function
let label = UILabel()
let stringValue = "How to\ncontrol\nthe\nline spacing\nin UILabel"
// Pass value for any one argument - lineSpacing or lineHeightMultiple
label.setLineSpacing(lineSpacing: 2.0) . // try values 1.0 to 5.0
// or try lineHeightMultiple
//label.setLineSpacing(lineHeightMultiple = 2.0) // try values 0.5 to 2.0
Or using label instance (Just copy & execute this code to see result)
let label = UILabel()
let stringValue = "How to\ncontrol\nthe\nline spacing\nin UILabel"
let attrString = NSMutableAttributedString(string: stringValue)
var style = NSMutableParagraphStyle()
style.lineSpacing = 24 // change line spacing between paragraph like 36 or 48
style.minimumLineHeight = 20 // change line spacing between each line like 30 or 40
// Line spacing attribute
attrString.addAttribute(NSAttributedStringKey.paragraphStyle, value: style, range: NSRange(location: 0, length: stringValue.characters.count))
// Character spacing attribute
attrString.addAttribute(NSAttributedStringKey.kern, value: 2, range: NSMakeRange(0, attrString.length))
label.attributedText = attrString
Swift 3
let label = UILabel()
let stringValue = "How to\ncontrol\nthe\nline spacing\nin UILabel"
let attrString = NSMutableAttributedString(string: stringValue)
var style = NSMutableParagraphStyle()
style.lineSpacing = 24 // change line spacing between paragraph like 36 or 48
style.minimumLineHeight = 20 // change line spacing between each line like 30 or 40
attrString.addAttribute(NSParagraphStyleAttributeName, value: style, range: NSRange(location: 0, length: stringValue.characters.count))
label.attributedText = attrString
I've made this simple extension that works very well for me:
extension UILabel {
func setLineHeight(lineHeight: CGFloat) {
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = 1.0
paragraphStyle.lineHeightMultiple = lineHeight
paragraphStyle.alignment = self.textAlignment
let attrString = NSMutableAttributedString()
if (self.attributedText != nil) {
attrString.append( self.attributedText!)
} else {
attrString.append( NSMutableAttributedString(string: self.text!))
attrString.addAttribute(NSAttributedStringKey.font, value: self.font, range: NSMakeRange(0, attrString.length))
}
attrString.addAttribute(NSAttributedStringKey.paragraphStyle, value:paragraphStyle, range:NSMakeRange(0, attrString.length))
self.attributedText = attrString
}
}
Copy this in a file, so then you can use it like this
myLabel.setLineHeight(0.7)
There's an alternative answer now in iOS 6, which is to set attributedText on the label, using an NSAttributedString with the appropriate paragraph styles. See this stack overflow answer for details on line height with NSAttributedString:
Core Text - NSAttributedString line height done right?
Here is a class that subclass UILabel to have line-height property : https://github.com/LemonCake/MSLabel
In Swift and as a function, inspired by DarkDust
// Usage: setTextWithLineSpacing(myEpicUILabel,text:"Hello",lineSpacing:20)
func setTextWithLineSpacing(label:UILabel,text:String,lineSpacing:CGFloat)
{
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = lineSpacing
let attrString = NSMutableAttributedString(string: text)
attrString.addAttribute(NSAttributedString.Key.paragraphStyle, value:paragraphStyle, range:NSMakeRange(0, attrString.length))
label.attributedText = attrString
}
According #Mike 's Answer, reducing the lineHeightMultiple is the key point. Example below, it work well for me:
NSString* text = label.text;
CGFloat textWidth = [text sizeWithAttributes:#{NSFontAttributeName: label.font}].width;
if (textWidth > label.frame.size.width) {
NSMutableParagraphStyle *paragraph = [[NSMutableParagraphStyle alloc] init];
paragraph.alignment = NSTextAlignmentCenter;
paragraph.lineSpacing = 1.0f;
paragraph.lineHeightMultiple = 0.75; // Reduce this value !!!
NSMutableAttributedString* attrText = [[NSMutableAttributedString alloc] initWithString:text];
[attrText addAttribute:NSParagraphStyleAttributeName value:paragraph range:NSMakeRange(0, text.length)];
label.attributedText = attrText;
}
SWIFT 3 useful extension for set space between lines more easily :)
extension UILabel
{
func setLineHeight(lineHeight: CGFloat)
{
let text = self.text
if let text = text
{
let attributeString = NSMutableAttributedString(string: text)
let style = NSMutableParagraphStyle()
style.lineSpacing = lineHeight
attributeString.addAttribute(NSParagraphStyleAttributeName,
value: style,
range: NSMakeRange(0, text.characters.count))
self.attributedText = attributeString
}
}
}
I've found a way where you can set the real line height (not a factor) and it even renders live in Interface Builder. Just follow the instructions below. Code is written in Swift 4.
Step #1: Create a file named DesignableLabel.swift and insert the following code:
import UIKit
#IBDesignable
class DesignableLabel: UILabel {
#IBInspectable var lineHeight: CGFloat = 20 {
didSet {
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.minimumLineHeight = lineHeight
paragraphStyle.maximumLineHeight = lineHeight
paragraphStyle.alignment = self.textAlignment
let attrString = NSMutableAttributedString(string: text!)
attrString.addAttribute(NSAttributedStringKey.font, value: font, range: NSRange(location: 0, length: attrString.length))
attrString.addAttribute(NSAttributedStringKey.paragraphStyle, value: paragraphStyle, range: NSRange(location: 0, length: attrString.length))
attributedText = attrString
}
}
}
Step #2: Place a UILabel into a Storyboard/XIB and set its class to DesignableLabel. Wait for your project to build (build must succeed!).
Step 3: Now you should see a new property in the properties pane named "Line Height". Just set the value you like and you should see the results immediately!
Here is a subclass of UILabel that sets lineHeightMultiple and makes sure the intrinsic height is large enough to not cut off text.
#IBDesignable
class Label: UILabel {
override var intrinsicContentSize: CGSize {
var size = super.intrinsicContentSize
let padding = (1.0 - lineHeightMultiple) * font.pointSize
size.height += padding
return size
}
override var text: String? {
didSet {
updateAttributedText()
}
}
#IBInspectable var lineHeightMultiple: CGFloat = 1.0 {
didSet {
updateAttributedText()
}
}
private func updateAttributedText() {
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineHeightMultiple = lineHeightMultiple
attributedText = NSAttributedString(string: text ?? "", attributes: [
.font: font,
.paragraphStyle: paragraphStyle,
.foregroundColor: textColor
])
invalidateIntrinsicContentSize()
}
}
Swift 3 extension:
import UIKit
extension UILabel {
func setTextWithLineSpacing(text: String, lineHeightMultiply: CGFloat = 1.3) {
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineHeightMultiple = lineHeightMultiply
paragraphStyle.alignment = .center
let attributedString = NSMutableAttributedString(string: text)
attributedString.addAttribute(NSParagraphStyleAttributeName, value: paragraphStyle, range: NSRange(location: 0, length: attributedString.length))
self.attributedText = attributedString
}
}
In Swift 2.0...
Add an extension:
extension UIView {
func attributesWithLineHeight(font: String, color: UIColor, fontSize: CGFloat, kern: Double, lineHeightMultiple: CGFloat) -> [String: NSObject] {
let titleParagraphStyle = NSMutableParagraphStyle()
titleParagraphStyle.lineHeightMultiple = lineHeightMultiple
let attribute = [
NSForegroundColorAttributeName: color,
NSKernAttributeName: kern,
NSFontAttributeName : UIFont(name: font, size: fontSize)!,
NSParagraphStyleAttributeName: titleParagraphStyle
]
return attribute
}
}
Now, just set your UILabel as attributedText:
self.label.attributedText = NSMutableAttributedString(string: "SwiftExample", attributes: attributesWithLineHeight("SourceSans-Regular", color: UIColor.whiteColor(), fontSize: 20, kern: 2.0, lineHeightMultiple: 0.5))
Obviously, I added a bunch of parameters that you may not need. Play around -- feel free to rewrite the method -- I was looking for this on a bunch of different answers so figured I'd post the whole extension in case it helps someone out there... -rab
Swift3 - In a UITextView or UILabel extension, add this function:
I added some code to keep the current attributed text if you are already using attributed strings with the view (instead of overwriting them).
func setLineHeight(_ lineHeight: CGFloat) {
guard let text = self.text, let font = self.font else { return }
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = 1.0
paragraphStyle.lineHeightMultiple = lineHeight
paragraphStyle.alignment = self.textAlignment
var attrString:NSMutableAttributedString
if let attributed = self.attributedText {
attrString = NSMutableAttributedString(attributedString: attributed)
} else {
attrString = NSMutableAttributedString(string: text)
attrString.addAttribute(NSFontAttributeName, value: font, range: NSMakeRange(0, attrString.length))
}
attrString.addAttribute(NSParagraphStyleAttributeName, value:paragraphStyle, range:NSMakeRange(0, attrString.length))
self.attributedText = attrString
}
Another answer... If you're passing the string programmatically, you need to pass a attributed string instead a regular string and change it's style.(iOS10)
NSMutableAttributedString * attrString = [[NSMutableAttributedString alloc] initWithString:#"Your \nregular \nstring"];
NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc] init];
[style setLineSpacing:4];
[attrString addAttribute:NSParagraphStyleAttributeName
value:style
range:NSMakeRange(0, attrString.length)];
_label.attributedText = attrString;
This should help with it. You can then assign your label to this custom class within the storyboard and use it's parameters directly within the properties:
open class SpacingLabel : UILabel {
#IBInspectable open var lineHeight:CGFloat = 1 {
didSet {
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = 1.0
paragraphStyle.lineHeightMultiple = self.lineHeight
paragraphStyle.alignment = self.textAlignment
let attrString = NSMutableAttributedString(string: self.text!)
attrString.addAttribute(NSAttributedStringKey.font, value: self.font, range: NSMakeRange(0, attrString.length))
attrString.addAttribute(NSAttributedStringKey.paragraphStyle, value:paragraphStyle, range:NSMakeRange(0, attrString.length))
self.attributedText = attrString
}
}
}
Swift 4 label extension. Creating NSMutableAttributedString before passing into function in case there are extra attributes required for the attributed text.
extension UILabel {
func setLineHeightMultiple(to height: CGFloat, withAttributedText attributedText: NSMutableAttributedString) {
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = 1.0
paragraphStyle.lineHeightMultiple = height
paragraphStyle.alignment = textAlignment
attributedText.addAttribute(.paragraphStyle, value: paragraphStyle, range: NSRange(location: 0, length: attributedText.length - 1))
self.attributedText = attributedText
}
}
This code worked for me (ios 7 & ios 8 for sure).
_label.numberOfLines=2;
_label.textColor=[UIColor whiteColor];
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.lineHeightMultiple=0.5;
paragraphStyle.alignment = NSTextAlignmentCenter;
paragraphStyle.lineSpacing = 1.0;
NSDictionary *nameAttributes=#{
NSParagraphStyleAttributeName : paragraphStyle,
NSBaselineOffsetAttributeName:#2.0
};
NSAttributedString *string=[[NSAttributedString alloc] initWithString:#"22m\nago" attributes:nameAttributes];
_label.attributedText=string;
Here is my solution in swift. The subclass should work for both attributedText and text property and for characterSpacing + lineSpacing. It retains the spacing if a new string or attributedString is set.
open class UHBCustomLabel : UILabel {
#IBInspectable open var characterSpacing:CGFloat = 1 {
didSet {
updateWithSpacing()
}
}
#IBInspectable open var lines_spacing:CGFloat = -1 {
didSet {
updateWithSpacing()
}
}
open override var text: String? {
set {
super.text = newValue
updateWithSpacing()
}
get {
return super.text
}
}
open override var attributedText: NSAttributedString? {
set {
super.attributedText = newValue
updateWithSpacing()
}
get {
return super.attributedText
}
}
func updateWithSpacing() {
let attributedString = self.attributedText == nil ? NSMutableAttributedString(string: self.text ?? "") : NSMutableAttributedString(attributedString: attributedText!)
attributedString.addAttribute(NSKernAttributeName, value: self.characterSpacing, range: NSRange(location: 0, length: attributedString.length))
if lines_spacing >= 0 {
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = lines_spacing
paragraphStyle.alignment = textAlignment
attributedString.addAttribute(NSParagraphStyleAttributeName, value:paragraphStyle, range:NSMakeRange(0, attributedString.length))
}
super.attributedText = attributedString
}
}