nsdata

NSDictionary to NSData and NSData to NSDictionary in Swift

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You can use NSKeyedArchiver and NSKeyedUnarchiver Example for swift 2.0+ var dictionaryExample : [String:AnyObject] = [“user”:”UserName”, “pass”:”password”, “token”:”0123456789″, “image”:0] let dataExample : NSData = NSKeyedArchiver.archivedDataWithRootObject(dictionaryExample) let dictionary:NSDictionary? = NSKeyedUnarchiver.unarchiveObjectWithData(dataExample)! as? NSDictionary Swift3.0 let dataExample: Data = NSKeyedArchiver.archivedData(withRootObject: dictionaryExample) let dictionary: Dictionary? = NSKeyedUnarchiver.unarchiveObject(with: dataExample) as! [String : Any] Screenshot of playground

NSData and UIImage

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I didn’t try UIImageJPEGRepresentation() before, but UIImagePNGRepresentation works fine for me, and conversion between NSData and UIImage is dead simple: NSData *imageData = UIImagePNGRepresentation(image); UIImage *image=[UIImage imageWithData:imageData];

Print the size (megabytes) of Data in Swift

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Use yourData.count and divide by 1024 * 1024. Using Alexanders excellent suggestion: func stackOverflowAnswer() { if let data = #imageLiteral(resourceName: “VanGogh.jpg”).pngData() { print(“There were \(data.count) bytes”) let bcf = ByteCountFormatter() bcf.allowedUnits = [.useMB] // optional: restricts the units to MB only bcf.countStyle = .file let string = bcf.string(fromByteCount: Int64(data.count)) print(“formatted result: \(string)”) } } With … Read more

Finding image type from NSData or UIImage

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If you have NSData for the image file, then you can guess at the content type by looking at the first byte: + (NSString *)contentTypeForImageData:(NSData *)data { uint8_t c; [data getBytes:&c length:1]; switch (c) { case 0xFF: return @”image/jpeg”; case 0x89: return @”image/png”; case 0x47: return @”image/gif”; case 0x49: case 0x4D: return @”image/tiff”; } return … Read more

How to compress/resize image on iOS before uploading to a server?

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This snippet will resize the image: UIGraphicsBeginImageContext(newSize); [image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)]; UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); The variable newSize is a CGSize and can be defined like so: CGSize newSize = CGSizeMake(100.0f, 100.0f);

NSData to [Uint8] in Swift

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You can avoid first initialising the array to placeholder values, if you go through pointers in a slightly convoluted manner, or via the new Array constructor introduced in Swift 3: Swift 3 let data = “foo”.data(using: .utf8)! // new constructor: let array = [UInt8](data) // …or old style through pointers: let array = data.withUnsafeBytes { … Read more

Best way to serialize an NSData into a hexadeximal string

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This is a category applied to NSData that I wrote. It returns a hexadecimal NSString representing the NSData, where the data can be any length. Returns an empty string if NSData is empty. NSData+Conversion.h #import <Foundation/Foundation.h> @interface NSData (NSData_Conversion) #pragma mark – String Conversion – (NSString *)hexadecimalString; @end NSData+Conversion.m #import “NSData+Conversion.h” @implementation NSData (NSData_Conversion) #pragma … Read more

Convert NSData to String?

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Objective-C You can use (see NSString Class Reference) – (id)initWithData:(NSData *)data encoding:(NSStringEncoding)encoding Example: NSString *myString = [[NSString alloc] initWithData:myData encoding:NSUTF8StringEncoding]; Remark: Please notice the NSData value must be valid for the encoding specified (UTF-8 in the example above), otherwise nil will be returned: Returns nil if the initialization fails for some reason (for example if … Read more

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)