计算时间差

    NSCalendar *cal = [NSCalendar currentCalendar];
    unsigned int unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;

    NSDateComponents *d = [cal components:unitFlags fromDate:date1 toDate:date2 options:0];
    
    int sec = [d hour]*3600+[d minute]*60+[d second];
    NSLog(@"second = %d",[d hour]*3600+[d minute]*60+[d second]);

加载UIView的XIB

 _replyView = [[[NSBundle mainBundle]loadNibNamed:@"NewRushListView" owner:self options:nil]lastObject];

UIColor转换为string再转换回来

 CGColorRef textDefaultColorRef = blockself.colorChooseView.colorPickerView.color.CGColor;
                 NSString *textDefaultColorStr = [CIColor colorWithCGColor:textDefaultColorRef].stringRepresentation;
                

                CIColor *color =[CIColor colorWithString:textDefaultColorStr];
                UIColor *c = [UIColor colorWithCIColor:color];