将NSDate转换为毫秒纪录时间

Question

我需要能够将日期转换为时间戳,一个以毫秒为单位的纪元.我在网上看到的只是将毫秒转换为NSDate,而不是相反.有帮助吗？

Answer 1

NSTimeInterval是一个双精度数,它包含小数点后的亚秒数据.根据您的需要,转换可能很简单,乘以1000即可.

- (void)testDateFormat
{
    NSDate *date = [NSDate date];
    NSLog(@"Time: %f", floor([date timeIntervalSince1970] * 1000));
    NSLog(@"Time: %f", floor([date timeIntervalSince1970]));
    NSLog(@"Time: %lli", [@(floor([date timeIntervalSince1970] * 1000)) longLongValue]);
    NSLog(@"Time: %lli", [@(floor([date timeIntervalSince1970])) longLongValue]);
}

// Result
// 2013-04-15 13:28:11.284 TestApp[10469:907] Time: 1366057691284.000000
// 2013-04-15 13:28:11.286 TestApp[10469:907] Time: 1366057691.000000
// 2013-04-15 13:28:11.287 TestApp[10469:907] Time: 1366057691284
// 2013-04-15 13:28:11.288 TestApp[10469:907] Time: 1366057691

Answer 2

timeIntervalSince1970将从1970年开始返回秒数.如果需要,还有其他timeIntervalSince方法.

https://developer.apple.com/library/mac/documentation/Cocoa/Reference/Foundation/Classes/NSDate_Class/Reference/Reference.html#//apple_ref/occ/instm/NSDate/timeIntervalSince1970