nsdata

问题 This code fails on iOS 8, although it would work on iOS 7 UIImage *imageTest = ... NSString *file = @"../Documents/Test.png"; NSString *fullpath = [[[NSBundle mainBundle] bundlePath] stringByAppendingPathComponent: file]; [UIImagePNGRepresentation(imageTest) writeToFile: fullpath atomically: YES]; UIImage *image = [UIImage imageNamed: file]; On iOS 8 I need to use this instead NSString *file = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0]

问题 In Xcode 5.0.2 on OS X 10.9.1: uint64_t data = 0x6ffa9e58938d7f5d; NSData *nsdataObj = [NSData dataWithBytes:&data length:8]; NSLog(@"%@", nsdataObj); Output: <5d7f8d93 589efa6f> How/why is the data getting reversed? 回答1: In this brave new world of Intel Macintoshes*, your integers are stored in memory in an absolutely bizzare fashion known as "little-endian byte order". That means that, unlike the more reasonable, human-readable format in which you wrote your number, the Least Significant

问题 I am trying to save data by NSUserDefaults . Here is my code @IBAction func saveBtn(sender: AnyObject) { var userName = nameLbl.text UserInfo.append(User(name: userName)) NSUserDefaults.standardUserDefaults().setObject(UserInfo, forKey: "UserInfo") userName = "" } But when i click on save button, it is showing Attempt to set a non-property-list object . I think, UserInfo array need to convert as NSData . Please tell me how can i do that? 回答1: You need to make your custom object conform to the

问题 I am making an application in which i have use Json parsing. With the help of json parsing i get photo url which is saved in string. To show images in my cell i use this code NSString *strURL=[NSString stringWithFormat:@"%@", [list_photo objectAtIndex:indexPath.row]]; NSData *imageData = [[NSData alloc] initWithContentsOfURL: [NSURL URLWithString: strURL]]; CGRect myImage =CGRectMake(13,5,50,50); UIImageView *imageView = [[UIImageView alloc] initWithFrame:myImage]; [imageView setImage:

问题 I've already managed to get the devicetoken from APNs. It's type of NSData. So i want to write this deviectoken into my mysql db. I've already tried to convert it to a string without luck. That was my way: NSString *tokenTMP = [[NSString alloc] initWithData:devToken encoding:NSASCIIStringEncoding]; If i have the deviceToken in a readable format. How do i use the token in php to send a request to the apns server? thanks a lot! 回答1: I added the following category to NSData - (NSString*)

问题 I am developing an iOS app and I am trying to do it with test-driven development . I've been reading a lot on the subject and one of the things I came across in a book is that tests are supposed to be fast, repeatable and reliable . As a consequence, when writing a test for networking code, the test should "simulate" the network, so that it can be executed regardless of network availability. In my code I have a method that retrieves an image from the internet with a URL, scales it and stores

问题 I need you to humor me during this question. This is somewhat pseudo code because the actual situation is quite complex. I wouldn't load an image this way unless I needed to. Assume that I need to. NSURL *bgImageURL = [NSURL URLWithString:@"https://www.google.com/images/srpr/logo3w.png"]; UIImage *img = [UIImage imageWithData:[NSData dataWithContentsOfURL:bgImageURL]]; [self.anIBOutletOfUIImageView setImage:img]; but I crash out with -[__NSCFData _isResizable]: unrecognized selector sent to

问题 Edit1: rob mayoff'answer is wonderful.And this is my own: -(NSData *)change:(NSString *)hexString { int j=0; Byte bytes[[hexString length]]; for(int i=0;i<[hexString length];i++) { int int_ch; unichar hex_char1 = [hexString characterAtIndex:i]; int int_ch1; if(hex_char1 >= '0' && hex_char1 <='9') int_ch1 = (hex_char1-48)*16; else if(hex_char1 >= 'A' && hex_char1 <='F') int_ch1 = (hex_char1-55)*16; else int_ch1 = (hex_char1-87)*16; i++; unichar hex_char2 = [hexString characterAtIndex:i]; int

问题 I am working on a e-banking iphone application. I am using WSS with XML-Signature to sign the requests to the customer's SOAP server. Since the iPhone device can not be trusted (due to jail-breaking), the customer requirement is to manually encrypt the RSA key pair (using AES128) before storing the keys into keychain. From what I have found so far, the keys are automatically added to the keychain when generated. So my idea is to extract the data afterwards (the same way the public key is

问题 I have the following enum: enum Enum: UInt8 { case A = 0x00 case B = 0x01 case C = 0x10 } I use the following code to convert it to NSData : var value = Enum.C let data = NSData(bytes: &value, length: 1) Naturally, I expect data to contain 0x10 , however, it contains 0x02 . For Enum.A it contains 0x00 and for Enum.B it contains 0x01 . To me, it looks like it stores an index of the value instead of its actual raw data. Could someone explain this behavior? P.S. If I use rawValue it works