iphone - 将 NSString 转换为 NSDate

Question

我正在将两个日期和时间字符串转换为 NSDate 但我总是得到错误的时间，但是得到正确的日期，我不知道为什么 xcode 给出错误的日志消息，我似乎有很多NSDate 代码但都不起作用，这个在我更改日期格式时起作用，告诉我如何处理时间格式

     NSDate * date;
    //Assume dateString is populated and of format NSString * dateString =@"2011-11-21 11:20";
    NSDateFormatter * dateFormatter = [[NSDateFormatter alloc] init];
    NSString *dateString =[NSString stringWithFormat:@"%@ %@", socialEvent.SocialEventsDC_EventDate,socialEvent.SocialEventsDC_EventStartTime];
    NSLog(@"%@ %@",socialEvent.SocialEventsDC_EventDate,socialEvent.SocialEventsDC_EventStartTime);

    [dateFormatter setDateFormat:@"MM/dd/yyyy HH:mm a"];
    if (dateString != nil)  {
        date = [dateFormatter dateFromString:dateString];
//        [date release];
    }

    NSLog(@"%@",date);

我的日志信息是

2013-04-25 10:45:04.417 BNI UK & Ire[450:5203] 01/20/2015 11:00 PM
2013-04-25 10:45:09.679 BNI UK & Ire[450:5203] 2015-01-20 07:00:00 +0000

虽然我的时间是11:00，但我的时间总是7:00:00，请帮帮我

Answer 1

试试这个代码...

    NSString * dateString =@"2011-11-21 11:20";
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    [formatter setDateFormat:@"yyyy-MM-dd hh:mm"];
    // [formatter setTimeZone:[NSTimeZone localTimeZone]];

    NSDate *datTemp = [formatter dateFromString:dateString];
    NSTimeZone* sourceTimeZone = [NSTimeZone timeZoneWithAbbreviation:@"GMT"];
    NSTimeZone* destinationTimeZone = [NSTimeZone systemTimeZone];

    NSInteger sourceGMTOffset = [sourceTimeZone secondsFromGMTForDate:datTemp];
    NSInteger destinationGMTOffset = [destinationTimeZone secondsFromGMTForDate:datTemp];
    NSTimeInterval interval = destinationGMTOffset - sourceGMTOffset;
    NSDate* destinationDate = [[[NSDate alloc] initWithTimeInterval:interval sinceDate:datTemp] autorelease];
    NSLog(@"\n\n\n Destination date is:- %@",destinationDate);