Xcode iOS生成.png文件并使用NSFileManager保存

Question

I am making an iOS app and I got a UIImage - I want to compress it into .png file and save it to the app's documents folder - I already have the path and all I need is how to convert the UIImage to .png and save it.

Thanks, Matan.

Answer 1

so the code is:

UIImage *yourImage = ...; //the image you have
NSString *targetPath = ...; // something like ~/Library/Documents/myImage.png

[UIImagePNGRepresentation(yourImage) writeToFile:targetPath atomically:YES];

Answer 2

For PNG:

UIImagePNGRepresentation

Returns the data for the specified image in PNG format

NSData * UIImagePNGRepresentation (
   UIImage *image
);

---

If you wanted JPEG instead:

UIImageJPEGRepresentation

Returns the data for the specified image in JPEG format.

NSData * UIImageJPEGRepresentation (
   UIImage *image,
   CGFloat compressionQuality
);

Answer 3

Image compression form is JPEG you can use different quality of jpg image

// for getting png image
 NSData*theImageData=UIImagePNGRepresentation(theImage);
// for JPG compression change fill value between less than 1 
 NSData*theImageData=UIImageJPEGRepresentation(theImage, 1);
// for converting raw data image to UIImage
 UIImage *imageOrignal=[UIImage imageWithData:theImageData];
// for saving in to photos gallery
 UIImageWriteToSavedPhotosAlbum(imageOrignal,nil,nil,nil);