終止應用程序-'NSInvalidArgumentException'，原因：'-[NSCFString objectForKey：]：無法識別的選擇器已發送到實例

Question

我在有人創建的iOS應用中有以下代碼。 但是，應用程序的這一部分會中斷並使其崩潰。

   if([[dictHomeSettings allKeys] containsObject:@"notify_url"]) {
        NSString *notifyUrl = [dictHomeSettings objectForKey:@"notify_url"];
        if(notifyUrl.length>0) {
            dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0ul);
            dispatch_async(queue, ^(void) {
//                    //  You may want to cache this explicitly instead of reloading every time.
//                    NSData *notifyData = [NSData dataWithContentsOfURL:[NSURL URLWithString:notifyUrl]];
//                    NSError* error;
//                    NSDictionary* json = [NSJSONSerialization JSONObjectWithData:notifyData
//                                                                         options:kNilOptions
//                                                                           error:&error];

                XMLDictionaryParser *xmlParser = [XMLDictionaryParser new];
                NSXMLParser *parser = [[NSXMLParser alloc] initWithContentsOfURL:[NSURL URLWithString:notifyUrl]];
                NSDictionary *aDict = [xmlParser dictionaryWithParser:parser];

                dispatch_async(dispatch_get_main_queue(), ^{
                    //NSLog(@"myNsArray : %@",aDict);
                    if([[aDict allKeys] containsObject:@"Notification"]) {
                        NSArray *array = [aDict objectForKey:@"Notification"];
                        if(array.count>0) {
                            [Common deletePreviousLocalNotifications];
                            for(NSDictionary *dictNotification in array) {
                                NSDateFormatter *dateFormatter = [NSDateFormatter new];
                                [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];

                                if([Common compareDate:[dictNotification objectForKey:@"StartTime"] isGreaterThanOrEqualDate:[dateFormatter stringFromDate:[NSDate date]]]) {
                                    NSLog(@"adding notification : %@",dictNotification);
                                    [Common addLocalNotificationAtDateTime:[dateFormatter dateFromString:[dictNotification objectForKey:@"StartTime"]] AlertBody:[dictNotification objectForKey:@"Message"] UserInfo:[NSDictionary dictionaryWithObjectsAndKeys:[dictNotification objectForKey:@"URL"], @"URL", nil]];
                                }
                            }
                        }
                    }
                });
            });

Answer 1

您正在嘗試在NSString對象上調用“ objectForKey”。 請檢查您假定為NSDictionary對象的對象是否實際上是NSDictionary對象實例。

Answer 2

顯然，您試圖在NSString對象上調用objectForKey 。 如圖所示[dictNotification objectForKey:@"StartTime"]是一個Number值，但您假設它是一個字符串（對此我不確定）。 因此，您在此通話中遇到了error

[Common compareDate:(Number *) isGreaterThanOrEqualDate:(NSString *)];

您可以在[NSObject doesNotRecognizeSelector:]上設置帶有此符號的Symbolic breakpoint ，以方便地debug代碼。