Question

使用下面的代码我收到以下错误：

2016-04-25 10:04:51.520 eCoss[1700:620301] -[__NSCFString managedObjectContext]: unrecognized selector sent to instance 0x160383a0
objc[1700]: EXCEPTIONS: throwing 0x14f94500 (object 0x14d07b70, a NSException)
objc[1700]: EXCEPTIONS: searching through frame [ip=0xffffffff sp=0x26a0b0] for exception 0x14f944e0
objc[1700]: EXCEPTIONS: searching through frame [ip=0x2 sp=0x26b980] for exception 0x14f944e0
objc[1700]: EXCEPTIONS: unwinding through frame [ip=0xffffffff sp=0x26a0b0] for exception 0x14f944e0
objc[1700]: EXCEPTIONS: unwinding through frame [ip=0x2 sp=0x26b980] for exception 0x14f944e0
objc[1700]: EXCEPTIONS: handling exception 0x14f944e0 at 0x231e33b9
objc[1700]: EXCEPTIONS: rethrowing current exception
objc[1700]: EXCEPTIONS: searching through frame [ip=0x6 sp=0x26b980] for exception 0x14f944e0
objc[1700]: EXCEPTIONS: terminating
objc[1700]: EXCEPTIONS: searching through frame [ip=0x1 sp=0x26b820] for exception 0x14f944e0
objc[1700]: EXCEPTIONS: catch(id)
objc[1700]: EXCEPTIONS: unwinding through frame [ip=0x1 sp=0x26b820] for exception 0x14f944e0
objc[1700]: EXCEPTIONS: handling exception 0x14f944e0 at 0x22a6f089
2016-04-25 10:04:51.582 eCoss[1700:620301] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFString managedObjectContext]: unrecognized selector sent to instance 0x160383a0'
*** First throw call stack:
(0x232d398b 0x22a6ee17 0x232d9325 0x232d6f51 0x232022f8 0x24dc0d9d 0x24dbffb1 0x5d06b 0x48f3d 0x48759 0x80a11 0x24d9b 0x27a70e61 0x27a70be7 0x27a70827 0x279e12fd 0x27a2ed13 0x279e12fd 0x27a2ed13 0x279e12fd 0x27a2ed13 0x27830e55 0x2786fde1 0x2786f593 0x27840055 0x2783e603 0x23295e6f 0x23295a5d 0x23293dcb 0x231e32e9 0x231e30d5 0x247d3ac9 0x278a80b9 0x1a4f1 0x22e8b873)
libc++abi.dylib: terminating with uncaught exception of type NSException

CODE

-(UIViewController*) displayViewFromString:(NSString *) identifier
{
     ontracAppDelegate* delegate = [ontracAppDelegate sharedAppDelegate];
     NSManagedObjectContext* moc = delegate.managedObjectContext;

    if ([identifier isEqualToString:@"Notes"]) {
        viewController = [[ontracPageNotesViewController alloc] init];

        NSString *requestURL = [NSString stringWithFormat: @"http://mydomain/%i/true",self.dataObject.dataPack.pack_id ];
        NSLog(@"%@", requestURL);
        //the request is built based on the string
        NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL: [[NSURL alloc] initWithString: requestURL]];
        [request setHTTPMethod:@"GET"];
        [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];

        NSDictionary *cookieProperties = [NSDictionary   dictionaryWithObjectsAndKeys:
                                      @"CAKEPHP", NSHTTPCookieName,
                                      @"mydomain.co.uk", NSHTTPCookieDomain,
                                      self.cookieValue, NSHTTPCookieValue,
                                      @"/", NSHTTPCookiePath,
                                      nil];
        NSHTTPCookie *cookie = [NSHTTPCookie cookieWithProperties:cookieProperties];
        NSArray* cookieArray = [NSArray arrayWithObjects: cookie, nil];
        NSDictionary * headers = [NSHTTPCookie requestHeaderFieldsWithCookies:cookieArray];
        [request setAllHTTPHeaderFields:headers];

        NSError *err;
        NSURLResponse *resp;
        //the return data is formatted into a Json Response
        NSData *returnData = [NSURLConnection sendSynchronousRequest: request returningResponse:&resp error:&err];
        NSError *error;
        NSDictionary *json = [NSJSONSerialization
                          JSONObjectWithData:returnData
                          options:kNilOptions
                          error:&error];



        NSMutableArray *responseObjects = [json objectForKey:@"response"];


        for (DataObject *dataObject in responseObjects) {
            //if ([dataObject.dataPack.pack_id intValue] == self.dataObject.dataPack.pack_id){
            NSArray * value = [responseObjects objectForKey:dataObject];
            //NSString *noteString = [[NSString alloc] init] ;
            NSString *noteCreated = [value objectForKey:@"created"];
            NSArray *imageArray = [value objectForKey:@"images"];
            NSString *noteString = [value objectForKey:@"note"];
            NSString * noteUpdated = [value objectForKey:@"updated"];

            NSLog(@"do %@", dataObject);

            Notes *note = [NSEntityDescription insertNewObjectForEntityForName:@"Notes" inManagedObjectContext:moc];


            NSLog(@"%@", note);

            note.notes = noteString;
            note.noteID = [NSNumber numberWithInteger: dataObject];
            //note.notes = self.textField.text;
            NSMutableArray * array = [[NSMutableArray alloc] init];
            for (NSString *image in imageArray) {

                NSString *image_created = [image objectForKey:@"created"];
                NSString *image_id = [image objectForKey:@"id"];
                NSString *image_data = [image objectForKey:@"image_data"];
                NSString *image_type = [image objectForKey:@"image_type"];

                NSLog(@"%@", image_id);

                NSData *pngData = [[NSData alloc]initWithBase64EncodedString:image_data options:NSDataBase64DecodingIgnoreUnknownCharacters];
                NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
                NSString *documentsPath = [paths objectAtIndex:0]; //Get the docs directory
                NSString *filePath = [documentsPath stringByAppendingPathComponent:[ NSString stringWithFormat:@"%@_%i_%@_notes_image.png", delegate.userName, self.dataObject.dataPack.pack_id, [self genRandStringLength:8]]]; //Add the file name
                [pngData writeToFile:filePath atomically:YES];

                [array addObject:filePath];

            }
            note.dataObject = dataObject;
            note.imageLocations = [NSKeyedArchiver archivedDataWithRootObject:array];
        NSLog(@"note %@", note);
            [dataObject addNotesObject:note];



        //}

      }

        //[[[splitView viewControllers] objectAtIndex:1]  pushViewController:notesView animated:YES];
    }
}

我在行（note.notes = noteString）处有换行符，这是产生错误的时间。在此之前，记录对象记录正常。我只是想将我从请求中获得的数据添加到其中。

核心数据

Notes.h

@class DataObject;

@interface Notes : NSManagedObject

@property (nonatomic, retain) NSData * imageLocations;
@property (nonatomic, retain) NSString * notes;
@property (nonatomic, retain) NSNumber * noteID;
@property (nonatomic, retain) DataObject *dataObject;

@end

Notes.m

#import "Notes.h"
#import "DataObject.h"


@implementation Notes

@dynamic imageLocations;
@dynamic notes;
@dynamic noteID;
@dynamic dataObject;

@end

managedObjectContext - appDelegate.m

- (NSManagedObjectContext *)managedObjectContext {

if (managedObjectContext != nil) {
    return managedObjectContext;
}

NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
if (coordinator != nil) {
    managedObjectContext = [NSManagedObjectContext new];
    [managedObjectContext setPersistentStoreCoordinator: coordinator];
}

return managedObjectContext;
}

Answer 1

您的问题似乎是您的数据类型全部搞砸了。您的JSON内容列为NSDictionary，您尝试取消NSMutableArray。使用当前代码，该阵列对我来说是不可能的。

然后迭代该数组，并尝试将内容视为DataObject个实例，但它们实际上可能是NSDictionary个实例。

您还使用responseObjects objectForKey:dataObject，显然是在数组上，但该调用应仅适用于字典。然后，您继续使用objectForKey代码所说的数组，但这又应该是字典。

所以，我有点困惑，无法准确说出这个问题的确切位置，但我认为您需要验证您正在使用的课程类型，并确保它完全是什么你认为是。

Answer 2

还显示了managedObjectContext创建的代码您是否在后台线程中创建了managedObjectContext？从第一行崩溃看起来，您的托管对象上下文没有带有notes属性的访问对象。

 [__NSCFString managedObjectContext]: unrecognized selector sent to instance 0x160383a0

最后验证您的JSON响应是否正确且没有条目。

Objective-c newbie - UIViewController managedObjectContext无法识别的选择器发送到实例

2 个答案: