ios - 格式化日期时出错

Question

我正在使用更改日期格式的代码:

NSDateFormatter *dateFormat=[NSDateFormatter new];
NSLocale *locale = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"];


    dateFormat.locale=locale;

   [dateFormat setDateFormat:@" dMMyyyy HH:mm:ss"];
   NSDate *date = [dateFormat dateFromString:Currentdate];
  NSDate *today = [dateFormat dateFromString:[datef stringFromDate:[NSDate date]]];
    NSLog(@"date %@ %@",date,Currentdate);

    NSCalendar *gregorian = [[NSCalendar alloc]
                             initWithCalendarIdentifier:NSGregorianCalendar];
    NSUInteger unitFlags =   NSHourCalendarUnit|NSMinuteCalendarUnit
     ;
    NSDateComponents *components = [gregorian components:unitFlags
                                                fromDate:date
                                                  toDate:today options:0];

但是我得到了错误:

  *** -[__NSCFCalendar components:fromDate:]: date cannot be nil
 I mean really, what do you think that operation is supposed to mean with a nil date?
 An exception has been avoided for now.
 A few of these errors are going to be reported with this complaint, then further.    violations will simply silently do whatever random thing results from the nil.
Here is the backtrace where this occurred this time (some frames may be missing due to       compiler optimizations):
    (
0   CoreFoundation                      0x30ffbad5 <redacted> + 92
1   CoreFoundation                      0x30ffba63 <redacted> + 74
2   VoxSci                              0x000d6997 -[MessagesViewController DayCounting] + 602
3   VoxSci                              0x000d858d -[MessagesViewController tableView:cellForRowAtIndexPath:] + 4000
4   UIKit                               0x33930315 <redacted> + 408
5   UIKit                               0x338d86cd <redacted> + 1800
6   UIKit                               0x338d7ef1 <redacted> + 184
7   UIKit                               0x337fe353 <redacted> + 346
8   QuartzCore                          0x33484943 <redacted> + 142
9   QuartzCore                          0x33480167 <redacted> + 350
10  QuartzCore                          0x3347fff9 <redacted> + 16
11  QuartzCore                          0x3347fa0d <redacted> + 228
12  QuartzCore                          0x3347f81f <redacted> + 314
13  QuartzCore                          0x3347954d <redacted> + 56
14  CoreFoundation                      0x31044f69 <redacted> + 20
15  CoreFoundation                      0x310428f7 <redacted> + 286
16  CoreFoundation                      0x31042c43 <redacted> + 738
17  CoreFoundation                      0x30fad471 CFRunLoopRunSpecific + 524
18  CoreFoundation                      0x30fad253 CFRunLoopRunInMode + 106
19  GraphicsServices                    0x35ce72eb GSEventRunModal + 138
20  UIKit                               0x33862845 UIApplicationMain + 1136

22  libdyld.dylib                       0x3b8cfab7 <redacted> + 2

)

我已经搜索过它但得到了类似的东西。有人可以告诉我问题所在或我错在哪里吗？ 任何帮助将不胜感激。提前致谢。

Answer 1

我觉得你打错了:) 尝试

[dateFormat setDateFormat:@"ddMMyyyy HH:mm:ss"];