按 NSDate 对表格部分进行排序

Question

我如何对NSDate 进行排序，以便如果某个日期的时间是周日早上 05:00，它会停留在周六“晚上”，但在列表中排在最后？

我从 JSON 数据中按日期对我的 tableview 部分进行排序

[[API sharedInstance] commandWithParams:[NSMutableDictionary dictionaryWithObjectsAndKeys:@"fodboldStream", @"command", nil] onCompletion:^(NSDictionary *json) {

    //got stream
    //NSLog(@"%@",json);
    [[API sharedInstance] setSoccer: [json objectForKey:@"result" ]];

    games = [json objectForKey:@"result"];


    sections = [NSMutableDictionary dictionary];

    for (NSDictionary *game in games) {
        NSNumber *gameType = game[@"dato"];
        NSMutableArray *gamesForType = sections[gameType];
        if (!gamesForType) {
            gamesForType = [NSMutableArray array];
            sections[gameType] = gamesForType;
        }
        [gamesForType addObject:game];


    }
   // NSLog(@"%@",sections);

    [fodboldTabel reloadData];
}];

这是我的部分标题：

- (NSString*) tableView:(UITableView*)tableView titleForHeaderInSection:(NSInteger)section {

    //...if the scetions count is les the 1 set title to opdating ...

    if ([[self.sections valueForKey:[[[self.sections allKeys] sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)] objectAtIndex:section]] count] < 1) {
        return @"Opdater....";

    } else {

        // ..........seting tabelheader titel to day and date..................
        NSString *str = [[[self.sections allKeys] sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)] objectAtIndex:section];

        NSDate *date = [NSDate date];
        NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init] ; // here we create NSDateFormatter object for change the Format of date..
        [dateFormatter setDateFormat:@"yyyy-MM-dd"]; //// here set format of date which is in your output date (means above str with format)
        date = [dateFormatter dateFromString:str];

        dateFormatter.locale=[[NSLocale alloc] initWithLocaleIdentifier:@"da_DK"];

        dateFormatter.dateFormat=@"MMMM";
        NSString * monthString = [[dateFormatter stringFromDate:date] capitalizedString];

        dateFormatter.dateFormat=@"EEEE";
        NSString * dayString = [[dateFormatter stringFromDate:date] capitalizedString];

        NSCalendar *calendar = [NSCalendar currentCalendar];
        NSInteger units = NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay | NSCalendarUnitWeekday;
        NSDateComponents *components = [calendar components:units fromDate:date];

        NSInteger year = [components year];
        //  NSInteger month=[components month];       // if necessary
        NSInteger day = [components day];
        //NSInteger weekday = [components weekday]; // if necessary


        NSString *sectionLbl = [NSString stringWithFormat: @"%@ %li %@ %li", dayString, (long)day, monthString, (long)year];
        return sectionLbl;
    }
}

这是一张图片，你可以看到标题写着 søndag（星期日），比赛从上午 1:35 开始，所以比赛在周日早上的电视上播放，但我希望在周六播出。部分.....所以实际上我只是看着“一天”从早上 5 点到凌晨 5 点而不是 00:00 - 00:00

Answer 1

您应该确定timeZone 与NSDateFormatter 一起使用，以便在构造节标题时使用。

例如，下面我展示了一系列事件，按when 属性排序，除了部分标题将位于某个预定时区，而不是我的设备的特定时区。所以，我首先使用适当的NSTimeZone 的日期格式化程序构建我的模型来支持我的表（一个Section 对象数组，每个对象都有一个items 数组）：

// Given some array of sorted events ...

NSArray *sortedEvents = [events sortedArrayUsingDescriptors:@[[[NSSortDescriptor alloc] initWithKey:@"when" ascending:YES]]];

// Let's specify a date formatter (with timezone) for the section headers.

NSDateFormatter *titleDateFormatter = [[NSDateFormatter alloc] init];
titleDateFormatter.dateStyle = NSDateFormatterLongStyle;
titleDateFormatter.timeZone = [NSTimeZone timeZoneWithName:@"GMT"];   // use whatever you want here; I'm just going to figure out sections in GMT even though I'm currently in GMT-5

// Now let's build our array of sections (and the list of events in each section)
// using the above timezone to dictate the sections.

self.sections = [NSMutableArray array];

NSString *oldTitle;
for (Event *event in sortedEvents) {
    NSString *title = [titleDateFormatter stringFromDate:event.when]; // what should the section title be

    if (![oldTitle isEqualToString:title]) {                          // if different than last one, add new section
        [self.sections addObject:[Section sectionWithName:title]];
        oldTitle = title;
    }

    [[(Section *)self.sections.lastObject items] addObject:event];    // add event to section
}

但是，当我显示单元格内容时，如果我不触摸timeZone 参数，它将默认显示当前时区的实际时间。

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *cellIdentifier = @"EventCell";
    EventCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];

    Section *section = self.sections[indexPath.section];
    Event *event = section.items[indexPath.row];

    // This formatter really should be class property/method, rather than instantiating 
    // it each time, but I wanted to keep this simple. But the key is that
    // I don't specify `timeZone`, so it defaults to current timezone.

    NSDateFormatter *formatter = [[NSDateFormatter alloc] init]; 
    formatter.timeStyle = NSDateFormatterMediumStyle;

    cell.eventTimeLabel.text = [formatter stringFromDate:event.when];

    // do additional cell population as you see fit

    return cell;
}

对于节标题，使用我在构建支持此表视图的模型的例程中提出的节名称（即，使用硬编码的时区）。

- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section {
    return [(Section *)self.sections[section] sectionName];
}

如您所见，时间列在当前时区中，但它们是按我在构建部分列表的代码中指定的预定NSTimeZone 分组的。

显然，我只是将 GMT 用作我的时区，但您可能希望将时区用作赛事举办地或 NBA 篮球赛的某个任意美国时区。但希望这能说明基本思想。创建部分时使用一个时区，显示实际时间时使用默认时区。