iOS如何隐藏UITableView行中的double值

Question

我忙于在TableView中显示事件列表的应用程序。每行/单元格我有一个事件显示事件的标题和日期。现在的问题是，当一天有两个或更多事件时，应用程序现在可以很好地在每个单元格中显示它们，但用户会反复看到该日期2次或更多次，这看起来效率低下且有点多余。所以我的想法是检查前一个单元格的日期与当前单元格的日期是否相似，这会隐藏当前单元格的日期（我无法完全删除它，因为用户能够将事件保存到日历中）。

我正在通过TouchXML将外部XML读取到SQLite数据库中。

这里是我的代码示例：

-(void) grabXMLData:(NSString *)dataAddress { 

    _managedObjectContext = [(DAFAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext]; 
    NSURL *url = [NSURL URLWithString: dataAddress]; 
    CXMLDocument *xmlParser = [[CXMLDocument alloc] initWithContentsOfURL:url options:0 error:nil]; 

    NSArray *resultNodes = NULL; 
    resultNodes = [xmlParser nodesForXPath:@"//month" error:nil]; 

    for (CXMLElement *resultElement in resultNodes) { 
     NSMutableDictionary *monthItem = [[NSMutableDictionary alloc] init]; 

     [monthItem setObject:[[resultElement attributeForName:@"name"] stringValue] forKey:@"name"]; 
     [monthItem setObject:[[resultElement attributeForName:@"month"] stringValue] forKey:@"month"]; 
     [monthItem setObject:[[resultElement attributeForName:@"year"] stringValue] forKey:@"year"]; 

     Month *aMonth = [NSEntityDescription insertNewObjectForEntityForName:@"Month" inManagedObjectContext:_managedObjectContext]; 
     aMonth.name = [monthItem objectForKey:@"name"]; 
     NSNumberFormatter * f = [[NSNumberFormatter alloc] init]; 
     aMonth.month = [f numberFromString:[monthItem objectForKey:@"month"]]; 
     aMonth.year = [f numberFromString:[monthItem objectForKey:@"year"]]; 

     NSArray *itemNodes = [resultElement children]; 

     for (CXMLElement *resultItem in itemNodes) { 
      NSMutableDictionary *item = [[NSMutableDictionary alloc] init]; 

      [item setObject:[[resultItem attributeForName:@"id"] stringValue] forKey:@"id"]; 

      int counter; 
      for(counter = 0; counter < [resultItem childCount]; counter++) { 
       [item setObject:[[resultItem childAtIndex:counter] stringValue] forKey:[[resultItem childAtIndex:counter] name]]; 

      } 

      Item *aItem = [NSEntityDescription insertNewObjectForEntityForName:@"Item" inManagedObjectContext:_managedObjectContext]; 
      NSNumberFormatter * f = [[NSNumberFormatter alloc] init]; 
      aItem.nr = [f numberFromString:[item objectForKey:@"id"]]; 
      aItem.title = [item objectForKey:@"title"]; 
      aItem.body = [item objectForKey:@"body"]; 
      aItem.date = [item objectForKey:@"date"]; 
      aItem.start = [item objectForKey:@"start"]; 
      aItem.end = [item objectForKey:@"end"]; 
     aItem.start2 = [item objectForKey:@"start2"]; 
      aItem.end2 = [item objectForKey:@"end2"]; 
      aItem.link_url = [item objectForKey:@"link_url"]; 
      aItem.month = aMonth; 
      [aMonth addItemObject:aItem]; 
     } 
    } 
} 

这是一个需要进行比较的项目日期。

这是我的tableview cellForRowAtIndex部分代码：

Month *aMonth = [_stages objectAtIndex:indexPath.section]; 
    NSSortDescriptor *sortDescriptorItem = [NSSortDescriptor sortDescriptorWithKey:@"nr" ascending:YES]; 
    NSArray *sortDescriptors = [NSArray arrayWithObjects: sortDescriptorItem, nil]; 
    _stagesPerMonth = [[aMonth.item allObjects] sortedArrayUsingDescriptors:sortDescriptors]; 
    Item *aItem = [_stagesPerMonth objectAtIndex:indexPath.row]; 

Answer 1

我想你使用具有用于显示日期标签的自定义单元格。对于cellForRowAtIndex伪代码将是：

Item *aItem = [_stagesPerMonth objectAtIndex:indexPath.row]; 
NSDate thisDate = aItem.date; 

// Obtain the date of the previous event or nil if this is the first event 
NSDate prevDate = indexPath.row > 0 ? _stagesPeMonth[indexPath.row - 1].date : nil; 

// Date label is hidden if the previous date is the same as this. 
dateLabel.hidden = [thisDate isEqualToDate: prevDate]; 

的语法可能是你的情况不同。