获取系统的日期和时间戳

Question

我已经创建了一个将数据字符串写入文本文件的方法。我想知道如何获取系统日期和时间并将其发送到文本文件？下面是方法：

-(void) writeToTextFile{ 

//get the documents dir 
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
NSString *documentsDirectory = [paths objectAtIndex:0]; 

//file name to write the data to using the documents directory: 
NSString *fileName = [NSString stringWithFormat:@"%@/movbandlog.txt", 
         documentsDirectory]; 
//create content 
NSString *content = @"Data received from device\n \n \n \n \nData sent to Portal\n \n \n \n \nData received to Portal"; 

//save to documents directory 
[content writeToFile:fileName 
      atomically:NO 
      encoding:NSStringEncodingConversionAllowLossy 
       error:nil]; 

} 

Answer 1

纯可可

使用NSDate和可选NSDateFormatter对其进行格式化：

NSDate *currentDate = [NSDate date]; 
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init]; 
[dateFormatter setDateFormat:@"dd.MM.YY HH:mm:ss"]; 
NSString *dateString = [dateFormatter stringFromDate:currentDate]; 
// NSLog(@"%@",dateString); 

// Adding your dateString to your content string 
NSString *content = [NSString stringWithFormat:@"Data received from device\n \n \n \n \nData sent to Portal\n \n \n \n \nData received to Portal\n \n \n \n \nData received at %@", dateString]; 

使用的Unix功能

你也可以考虑using unix functions for unlocalized日期（timest安培）

struct tm sometime; 
const char *formatString = "%Y-%m-%d %H:%M:%S %z"; 
(void) strptime_l("2005-07-01 12:00:00 -0700", formatString, &sometime, NULL); 
NSLog(@"NSDate is %@", [NSDate dateWithTimeIntervalSince1970: mktime(&sometime)]); 
// Output: NSDate is 2005-07-01 12:00:00 -0700