“The operation couldn’t be completed. (Cocoa error

问题:

I have this code, which should be working perfectly, but I can't udnerstand why it isn't:

+(NSString *)writeImageToFile:(UIImage *)image {

    NSData *fullImageData = UIImageJPEGRepresentation(image, 1.0f);


    NSString *path = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/Images/"];

    NSFileManager *fileManager = [NSFileManager defaultManager];
    BOOL isDirectory = NO;
    BOOL directoryExists = [fileManager fileExistsAtPath:path isDirectory:&isDirectory];
    if (directoryExists) {
        NSLog(@"isDirectory: %d", isDirectory);
    } else {
        NSError *error = nil;
        BOOL success = [fileManager createDirectoryAtPath:path withIntermediateDirectories:NO attributes:nil error:&error];
        if (!success) {
            NSLog(@"Failed to create directory with error: %@", [error description]);
        }
    }

    NSString *name = [NSString stringWithFormat:@"%@.jpg", [JEntry generateUuidString]];
    NSString *filePath = [path stringByAppendingPathComponent:name];
    NSError *error = nil;
    BOOL success = [fullImageData writeToFile:filePath options:NSDataWritingAtomic error:&error];
    if (!success) {
        NSLog(@"Failed to write to file with error: %@", [error description]);
    }

    return filePath;
}

It passed the directoryExists without an error, but when it gets to writeToFile, it gives me this error:

Error Domain=NSCocoaErrorDomain Code=512 "The operation couldn’t be completed. (Cocoa error 512.)" UserInfo=0x5634ee0 {NSFilePath=/var/mobile/Applications/5E25F369-9E05-4345-A0A2-381EDB3321B8/Documents/Images/18DAE0BD-6CB4-4244-8ED1-9031393F6DAC.jpg, NSUnderlyingError=0x5625010 "The operation couldn’t be completed. Not a directory"}

Any ideas why this might be?

回答1:

I was able to reproduce your error when writing a file first in the path @"Documents/Images/", then trying to write the image using your code.

I think there are two possible scenarios for this:

1) You created that file by mistake at a previous execution of your app. This will be solved if you reset the simulator using the menu: iOS Simulator > Reset Contents and Settings, and uninstalling the app from your device: Long press > click on the x symbol.

2) There is some code somewhere else in your app that creates this file. If this is the case, you should find this code and remove it.

回答2:

From FoundationErrors.h:

NSFileWriteUnknownError = 512

Try using withIntermediateDirectories:YES.

回答3:

In my case a period '.' in the directory name (e.g. ~/Documents/someDir.dir/somefile) was the cause of the problem. I removed the offending character and the error disappeared.