带有格式化NSDate的NSFetchedResultsController titleForHeaderInSection [英] NSFetchedResultsController titleForHeaderInSection with formatted NSDate

问题描述

在我的Core Data应用程序中，我使用的是FetchedResultsController。通常要在UITableView中为标题设置标题，你可以实现以下方法：

   - （NSString *）tableView :( UITableView *）tableView titleForHeaderInSection：（NSInteger）section {
 id< NSFetchedResultsSectionInfo> sectionInfo = [[< #Fetched results controller＃> ]] objectAtIndex：section]; 
 return [sectionInfo name]; 
} 
  

其中[sectionInfo name]返回一个NSString。

我的sectionKeyPath基于一个NSDate，这一切都很好，除了它给我的部分标题是原始日期描述字符串（例如12/12/2009 12:32:32 +0100）在标题中看起来有点混乱！

所以我想在此使用日期格式化程序来制作一个很好的标题，如2010年4月17日，但我可以'用[sectionInfo name]做这个，因为这是NSString！任何想法？

非常感谢

解决方案

我找到了一个解决方案：

   - （NSString *）tableView：（UITableView *）tableView titleForHeaderInSection：（NSInteger）section {
 //返回每个部分标题的标题。标题是日期。 
 id< NSFetchedResultsSectionInfo> sectionInfo = [[fetchedResultsController sections] objectAtIndex：section]; 
 NSArray * objects = [sectionInfo objects]; 
 NSManagedObject * managedObject = [objects objectAtIndex：0]; 
 NSDateFormatter * formatter = [[NSDateFormatter alloc] init]; 
 [formatter setDateStyle：NSDateFormatterMediumStyle]; 
 NSDate * headerDate =（NSDate *）[managedObject valueForKey：@itemDate]; 
 NSString * headerTitle = [formatter stringFromDate：headerDate]; 
 [格式化程序发布]; 
返回headerTitle; 
} 
  

请仔细看看，如果你知道更好的方法请说！ / p>

否则如果您遇到类似问题，我希望这会有所帮助！

In my Core Data app I am using a FetchedResultsController. Usually to set titles for headers in a UITableView you would implement the following method like so:

- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section { 
    id <NSFetchedResultsSectionInfo> sectionInfo = [[<#Fetched results controller#> sections] objectAtIndex:section];
    return [sectionInfo name];
}

where [sectionInfo name] returns a NSString.

my sectionKeyPath is based on an NSDate and this all works fine apart from the section headers it gives me are the raw date description strings (e.g. 12/12/2009 12:32:32 +0100) which look a bit of a mess in a header!

So I want to use a date formatter on this to make a nice header like "Apr 17 2010" but I can't do that with the [sectionInfo name] as this is NSString! Any Ideas?

Many Thanks

解决方案

I found a solution:

- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section {
    //Returns the title for each section header. Title is the Date.
    id <NSFetchedResultsSectionInfo> sectionInfo = [[fetchedResultsController sections] objectAtIndex:section];
    NSArray *objects = [sectionInfo objects];
    NSManagedObject *managedObject = [objects objectAtIndex:0];
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    [formatter setDateStyle:NSDateFormatterMediumStyle];
    NSDate *headerDate = (NSDate *)[managedObject valueForKey:@"itemDate"];
    NSString *headerTitle = [formatter stringFromDate:headerDate];
    [formatter release];
    return headerTitle;
}

Please look over this, if you know of a better way please say!

Otherwise if your stuck with a similar problem I hope this helps!

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