iphone - 将字符串转换为日期的日期比较

Question

如何将字符串随时间改变为时间 我正在编写代码，但没有运气

NSString *comingdate = [sParams valueForKey:@"showdate"];
NSDateFormatter *dateformate = [[NSDateFormatter alloc]init];
[dateformate setDateFormat:@"yyyy-MM-dd"];
NSDate *todate = [dateformate dateFromString:comingdate];
NSLog(@"%@", todate);

/* 从 showdate 我得到的日期是 yyyy-MM-dd 但我想将该字符串转换为带时间的日期 任何人都可以提供线索或使用清晰的代码

Answer 1

NSDate *firstDate=[[NSDate alloc]init];
    NSString *comingdate = [sParams valueForKey:@"showdate"]; // yyyy-MM-dd
    NSString *time = @"01:37:42"; // HH:mm:ss
    comingdate = [comingdate stringByAppendingFormat:@" %@", time];
    NSDateFormatter *dateformate = [[NSDateFormatter alloc] init];
    [dateformate setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    NSDate *secondDate = [dateformate dateFromString:comingdate];
    NSTimeInterval timeDifference = [secondDate timeIntervalSinceDate:firstDate];
    NSLog(@"%f",timeDifference);