objective-c - 将字符串转换为 NSDate

Question

如何NSDate在 iOS 上将字符串转换为字符串？

Answer 1

NSString *dateStr = @"20100223";

// Convert string to date object
NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:@"yyyyMMdd"];
NSDate *date = [dateFormat dateFromString:dateStr];  

// Convert date object to desired output format
[dateFormat setDateFormat:@"EEEE MMMM d, YYYY"];
dateStr = [dateFormat stringFromDate:date];  
[dateFormat release];

希望这会帮助你。

Answer 2

你会想看看NSDateFormatter。确定日期字符串的格式，然后用于dateFromString:将字符串转换为 NSDate 对象。

Answer 3

NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:@"dd/MM/YYYY"];
NSDate *date = [dateFormat dateFromString:dateStr];  
list = [self getYear:date];


- (NSMutableArray *)getYear:(NSDate*)date
{
    NSDateComponents *components = [[NSCalendar currentCalendar] components:NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear fromDate:date];

    int year = [components year];
    int month = [components month];
    int day = [components day];
    NSLog(@"%d",year);

    NSMutableDictionary *dateDict = [[NSMutableDictionary alloc] initWithObjectsAndKeys:[NSString stringWithFormat:@"%d", day], @"day", [NSString stringWithFormat:@"%d", month], @"month", [NSString stringWithFormat:@"%d", year], @"year", nil];

    return dateDict;
}

Answer 4

我在 Swift 中的工作版本

func dateFor(timeStamp: String) -> NSDate
{
    let formater = NSDateFormatter()
    formater.dateFormat = "HH:mm:ss:SSS - MMM dd, yyyy"
    return formater.dateFromString(timeStamp)!
}


func timeStampFor(date: NSDate) -> String
{
    let dateFormatter = NSDateFormatter()
    dateFormatter.dateFormat = "HH:mm:ss:SSS - MMM dd, yyyy"

    return dateFormatter.stringFromDate(date)
}

Answer 5

即使您有 sqlite DB，也是一种简单的方法：

// NSTimeInterval is basically typedef of double so you can receive it as double also.
NSTimeInterval *current = [[NSDate date] timeIntervalSince1970]; 
[DB addToDB:current];

//retrieve the date from DB
NSDate *retrievedDateItem = [[NSDate alloc] initWithTimeIntervalSince1970:[getDBValueAsDouble]]; //convert it from double (NSTimeInterval) to NSDate
// Set the style
[dateFormatter setDateStyle:NSDateFormatterMediumStyle];
[dateFormatter setTimeStyle:NSDateFormatterMediumStyle];
// Converted to string
NSString *convertedDate = [dateFormatter stringFromDate:retrievedDateItem];

此示例的输出：

2015 年 8 月 3 日，下午 12:27:50

Answer 6

+(NSDate*)str2date:(NSString*)dateStr{
    if ([dateStr isKindOfClass:[NSDate class]]) {
        return (NSDate*)dateStr;
    }

    NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
    [dateFormat setDateFormat:@"yyyy-MM-dd"];
    NSDate *date = [dateFormat dateFromString:dateStr];
    return date;
}