NSDate使用

一、将字符串时间转化为NSDate，并打印

        NSString *string = @"2013-08-12 20:13:43";
        
         NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
        //格式一定要一致，否则无法转换
        formatter.dateFormat = @"yyyy-MM-dd HH:mm:ss";
       
        NSDate *date = [formatter dateFromString: string];
        NSLog(@"
%@", date);

二、格式化NSDate,转换成字符串并打印

        NSDate *date = [NSDate date];
        NSString *time;
        NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
        dateFormatter.dateFormat = @"yyyy-MM-dd HH:mm:ss";
        time = [dateFormatter stringFromDate:date];
        NSLog(@"
%@", date);