Question

我有一个UIView，就像一个日程表（使用XCode 4.6，iOS 6.2和Storyboard编写的iPad应用程序）。我实际上有两（2）个UIVIews，一个在窗口的上半部分，另一个在下半部分。上半部分有一个日历;和一个低于它的网格。当用户点击具有约会的那一天时，它们将被绘制在底部的UIView上。用户可以点击约会的任何一天，并删除旧的，新数据将在底部视图中绘制。

这很有效，除非当天没有被约用的约会，在这种情况下旧数据仍然存在，而不是以某种方式被删除。我尝试过[self setNeedsDisplay]，但由于没有任何改变，所以没有画出来。有没有办法使UIView的内容无效以强制重绘它而没有数据？

更新：以下是绘制约会的代码：

- (void)drawRect:(CGRect)rect  {

//  load dictionary files from plists
NSString *path = [[NSBundle mainBundle] bundlePath];
//    NSLog(@"\n\npath %@",path);
//
NSString *timesFinalPath = [path stringByAppendingPathComponent:@"startingTimes.plist"];  //  do starting times
NSDictionary *startDict = [NSDictionary dictionaryWithContentsOfFile:timesFinalPath];

NSString *namesFinalPath = [path stringByAppendingPathComponent:@"techNames.plist"];  //  do tech names
NSDictionary *techDict = [NSDictionary dictionaryWithContentsOfFile:namesFinalPath];
//    NSLog(@"\nPath: %@\ntechDict.count: %d\nstartDict.count %d", path, techDict.count, startDict.count);

//    NSLog(@"nbr of recognizers: %lu", (unsigned long)self.gestureRecognizers.count);


//  find out how many appointments we have for this day
SingletonAppointments *sharedInstance = [SingletonAppointments sharedInstance];  //  initialize

if(sharedInstance.globalApptList.count > 0) {

    for(int i = 0; i < sharedInstance.globalApptList.count; i++)  {  //  get customer apointments for this day

        AppointmentInfo *apptObject = [sharedInstance.globalApptList objectAtIndex:i];

        //NSLog(@"apptObject.aApptKey: %@", apptObject.aApptKey);

        //  using apptObject.aApptKey, get the client's name
        NSPredicate *predicate =  ([NSPredicate predicateWithFormat:@"(aClientKey = %@)", apptObject.aApptKey]);
        clientInfo = [ClientInfo MR_findAllWithPredicate: predicate];
        NSString *cliInfo;
        for (ClientInfo *cli in clientInfo) {
            cliInfo = cli.aClientName;  //  found client name
        }

        //  settings for name drawing
        const float nameFontSize = 14;
        UIFont *hourfont=[UIFont systemFontOfSize: nameFontSize];

        //  now compute the duration
        NSDateFormatter *df = [[NSDateFormatter alloc] init];
        [df setDateFormat:@"HH:mm"];
        NSTimeInterval interval = [apptObject.aEndTime timeIntervalSinceDate:apptObject.aStartTime];
        int hours = (int)interval / 3600;             // integer division to get the hours part
        int minutes = (interval - (hours*3600)) / 60; // interval minus hours part (in seconds) divided by 60 yields minutes
        //            NSString *duration = [NSString stringWithFormat:@"%d:%02d", hours, minutes];

        //  localize time
        NSDate *sTime = [self localizeDate: apptObject.aStartTime];
        //            NSDate *eTime = [self localizeDate: apptObject.aEndTime];
        //            NSLog(@"\n\nsTime: %@    eTime: %@", sTime, eTime);
        //            NSLog(@"\nlocalized sTime: %@\nlocalized eTime %@", sTime, eTime);

        //  determine time slot  (dictiionary starts at 0900... must accomodate for that)
        NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
        [formatter setTimeZone:[NSTimeZone timeZoneWithName:@"GMT"]];  //Optionally for time zone converstions
        [formatter setDateFormat:@"HH:mm"];

        //  get time shop opens and closes
        PreferenceData *prefDataFound = [PreferenceData MR_findFirst];
        if(prefDataFound)  {  //  fill the times
            startHour = prefDataFound.aShopOpens;
            endHour = prefDataFound.aShopCloses;
        }
        //            NSLog(@"startHour: %@    endHour: %@",startHour, endHour);

        //  now, get first time slot in dictionary
        NSArray *ts = [startDict allKeysForObject:[NSNumber numberWithInt:5]];  //  comes back with one entry: 9:00

        //  clean it (remove colon)
        NSString *dictValue = ts[0];
        NSString *cleanDictValue = [dictValue stringByReplacingOccurrencesOfString:@":" withString:@""];

        //  convert to int
        int dictStartTime = [cleanDictValue intValue];
        int intStartHour = [startHour intValue];

        //  compute gridTimeOffset
        float gridTimeOffset = dictStartTime - intStartHour;

        NSString *stringFromDate = [formatter stringFromDate:sTime];
        //            NSLog(@"\n\nstringFromDate: %@",stringFromDate);
        //            NSLog(@"\nserviceTech: %@", apptObject.aServiceTech);

        //  find the correct column by tech name
        NSNumber *techColumn = [techDict objectForKey:apptObject.aServiceTech];
        //            NSLog(@"\nserviceTech: %@, techColumn: %@", apptObject.aServiceTech, techColumn);

        //  set the context
        CGContextRef context = UIGraphicsGetCurrentContext();


        //  draw the name...  (x refers to column; y refers to time slot)
        [[UIColor blueColor] set];  //  sets color of customer name
        NSNumber *timeSlot = [startDict objectForKey:stringFromDate];
        float correctedSlot = [timeSlot floatValue] + gridTimeOffset;  //  corrected slot info for name and rectangle
        [cliInfo drawAtPoint:CGPointMake([techColumn floatValue], correctedSlot) withFont:hourfont];
        //            NSLog(@"\ntimeSlot: %@    adjusted: %@", [timeSlot floatValue], ([timeSlot floatValue] - gridTimeOffset));


        //  make some settings for the blocking
        UIGraphicsBeginImageContext(self.bounds.size);
        //            CGContextSetStrokeColorWithColor(context, [UIColor blackColor].CGColor);
        //            CGContextSetLineWidth(context, 1.0);

        //  get the CGContextRef for drawing the rectangle
        CGContextSetFillColorWithColor(context, [[[UIColor grayColor] colorWithAlphaComponent: 0.3] CGColor]);

        //            NSNumber *startPos = [startDict objectForKey:stringFromDate];
        int shadeHeight = ((hours * 4) + (minutes / 15)) * 25;  //  compute starting y value

        //            CGContextFillRect(context, CGRectMake([techColumn floatValue], [startPos floatValue], 218, (float)shadeHeight));
        CGContextFillRect(context, CGRectMake([techColumn floatValue], correctedSlot, 218, (float)shadeHeight));

        UIGraphicsEndImageContext();  //  end the context so the other appointments will draw
    }

}

}

Answer 1

这应该在控制底部视图的视图控制器的回调中处理。（如果您有一个控制顶部和底部的视图控制器，则同样适用。）在其更新方法（应在选择一天时调用，包括空天）时，应该有类似的内容。

-(void)update {
    if (selectedDay.events && selectedDay.events.count) {
       // do your normal update
    }
    else {
       // empty the view
    }
}

请注意，如果底部视图是或具有表视图，则重置数据数组或集（上面引用为selectedDay.events）并调用

[_tableView reloadData];

如果您有其他方案，则必须“手动”清空它。

修改

正如spokane-dud指出的那样，数据源单身人士存在缺陷。在适当的时候，数据必须明确地设置为空。

if(appointmentInfo.count > 0) { for (AppointmentInfo *appt in appointmentInfo) { sharedInstance.globalApptList = appointmentInfo; // move data to sharedInstance } } else { sharedInstance.globalApptList = nil; }

如何使UIView的内容无效以强制重绘？

1 个答案: