// Convert string to date 

NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:@"yyyyMMdd"];
NSDate *date = [dateFormat dateFromString:dateStr];  

// Convert Date to string

[dateFormat setDateFormat:@"EEEE MMMM d, YYYY"];
dateStr = [dateFormat stringFromDate:date];  
[dateFormat release];

// Convert string to date 

NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:@"yyyyMMdd"];
NSDate *date = [dateFormat dateFromString:dateStr];  

// Convert Date to string

[dateFormat setDateFormat:@"EEEE MMMM d, YYYY"];
dateStr = [dateFormat stringFromDate:date];  
[dateFormat release];

根据Swift 2.2

你可以很容易地得到NSDate从字符串和字符串从NSDate。 如。

第一次设置日期格式化程序

let formatter = NSDateFormatter();
formatter.dateStyle = NSDateFormatterStyle.MediumStyle
formatter.timeStyle = .NoStyle
formatter.dateFormat = "MM/dd/yyyy"

现在从字符串中获取date，反之亦然。

let strDate = formatter.stringFromDate(NSDate())
print(strDate)
let dateFromStr = formatter.dateFromString(strDate)
print(dateFromStr)

现在享受。

如果现在有人有兴趣在Swift中做这样的事情，我已经开始做了一些事情，尽管它并不完美。

func detectDate(dateString: NSString) -> NSDate {

    var error: NSError?
    let detector: NSDataDetector = NSDataDetector.dataDetectorWithTypes(NSTextCheckingType.Date.toRaw(), error: &error)!

    if error == nil {
        var matches = detector.matchesInString(dateString, options: nil, range: NSMakeRange(0, dateString.length))

        let currentLocale = NSLocale.currentLocale()
        for match in matches {
            match.resultType == NSTextCheckingType.Date
            NSLog("Date: \(match.date.description)")
            return match.date
        }
    }
    return NSDate()
}

使用这个方法将NSString转换为NSdate:

-(NSDate *)getDateFromString:(NSString *)pstrDate
{
    NSDateFormatter* myFormatter = [[NSDateFormatter alloc] init];
    [myFormatter setDateFormat:@"dd/MM/yyyy"];
    NSDate* myDate = [myFormatter dateFromString:pstrDate];
    return myDate;
}

为什么不给NSString添加一个category ?

// NSString+Date.h
@interface NSString (Date)
+ (NSDate*)stringDateFromString:(NSString*)string;
+ (NSString*)stringDateFromDate:(NSDate*)date;
@end


// NSString+Date.m
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
[dateFormatter setDateFormat:@"EEE, dd MMM yyyy HH:mm:ss ZZZ"];

NSDate *date = [dateFormatter dateFromString:stringDate ];
[dateFormatter release];
+ (NSDateFormatter*)stringDateFormatter
{
    static NSDateFormatter* formatter = nil;
    if (formatter == nil)
    {
        formatter = [[NSDateFormatter alloc] init];
        [formatter setDateFormat:@"EEE, dd MMM yyyy HH:mm:ss ZZZ"];
    }   
    return formatter;
}

+ (NSDate*)stringDateFromString:(NSString*)string
{
    return [[NSString stringDateFormatter] dateFromString:string];
}

+ (NSString*)stringDateFromDate:(NSDate*)date
{
    return [[NSString stringDateFormatter] stringFromDate:date];
}


// Usage (#import "NSString+Date.h") or add in "YOUR PROJECT".pch file
NSString* string = [NSString stringDateFromDate:[NSDate date]];
NSDate* date = [NSString stringDateFromString:string];