NSDateFormatter为2015-02-13 17:16:00 +0000

Question

NSString *value = [newProperties objectForKey:key]
NSLog(@"%@",value);
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"yyyy-MM-dd hh:mm:ss zzzz"];
NSTimeZone *gmt = [NSTimeZone timeZoneWithAbbreviation:@"GMT"];
[dateFormatter setTimeZone:gmt];
NSDate *dateFromString = [dateFormatter dateFromString:value];

value is 2015-02-13 17:16:00 +0000
But I am getting crash in last line which says :

'-[__NSTaggedDate length]: unrecognized selector sent to instance 0xe41ba8e68d000000'

Answer 1

The error is clearly showing that value is already an NSDate , not an NSString .

All of your code can be replaced with one line:

NSDate *value = [newProperties objectForKey:key];

You can verify that value is a date by logging its class:

NSLog(@"value class = %@", [value class]);

As a side note. If you really did have a date string in the format shown, your format specifier would need to be yyyy-MM-dd HH:mm:ss Z .