什麼是最好的地方重新加載UITableView或UICollectionView中的數據ios

Question

我正在使用AFNetworking加載數據。在我的情況下，我加載數據到一個collectionview。 我加載我的自定義方法中的數據，並在裏面我重新加載collectionview數據。 而我在viewDidLoad方法中調用這個方法。爲什麼我問這是，它需要更多的時間來加載數據。我想這是因爲地方的我重裝的CollectionView data.I想知道，我可以像viewWillAppear中的另一種方法重載的CollectionView數據加快這一進程，或任何other.hope你你help.thank

- (void)viewDidLoad { 
    [super viewDidLoad]; 

    [self loadcategoryData]; 

    SWRevealViewController *revealcontroller = self.revealViewController; 
    if (revealcontroller) { 
     [self.sideBarbutton setTarget:self.revealViewController]; 
     [self.sideBarbutton setAction:@selector(revealToggle:)]; 
     [self.view addGestureRecognizer:self.revealViewController.panGestureRecognizer]; 
    } 

    // Do any additional setup after loading the view. 
} 


- (void)viewWillAppear:(BOOL)animated 
{ 
    [super viewWillAppear:animated]; 


    [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES]; 

} 

- (void)viewDidAppear:(BOOL)animated 
{ 
    [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES]; 
} 

- (void)viewDidDisappear:(BOOL)animated 
{ 
    [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO]; 
} 


- (void)viewWillDisappear:(BOOL)animated 
{ 
    [super viewWillDisappear:animated]; 

    [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO]; 
} 




- (void)didReceiveMemoryWarning { 
    [super didReceiveMemoryWarning]; 
    // Dispose of any resources that can be recreated. 
} 

- (void)loadcategoryData 
{ 
    post = nil; 
    NSString *mainurl = [NSString stringWithFormat:@"some url"]; 
    AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager]; 
    manager.responseSerializer.acceptableContentTypes = [manager.responseSerializer.acceptableContentTypes setByAddingObject:@"text/html"]; 
    [manager GET:mainurl parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) { 

     posts = (NSDictionary *)responseObject; 
     post = [NSMutableArray array]; 
     for(NSDictionary *all in posts) 
     { 
      Categories *category = [Categories new]; 
      category.title = [all objectForKey:@"catname"]; 
      category.firsturl = [all objectForKey:@"url"]; 

      [self.maincollectionView reloadData]; 
      //call for images 

      imagespost = nil; 
      NSString *imageUrl = [NSString stringWithFormat:@"%@", category.firsturl]; 
      AFHTTPRequestOperationManager *managerone = [AFHTTPRequestOperationManager manager]; 
      [managerone GET:imageUrl parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) { 



       imagesposts = (NSDictionary *)responseObject; 
       NSArray *resultone = [imagesposts objectForKey:@"posts"]; 
       imagespost = [NSMutableArray array]; 
       if ([resultone count]) { 
        NSDictionary *firstpost = resultone[0]; 
//     Categories *newmogocat = [Categories new]; 


        NSDictionary *thumbnail_images = [firstpost objectForKeyedSubscript:@"thumbnail_images"]; 
        NSDictionary *thumbnail = [thumbnail_images objectForKey:@"thumbnail"]; 
        category.imageOneUrl = [NSString stringWithFormat:@"%@",[thumbnail objectForKey:@"url"]]; 
//     NSLog(@"%@", newmogocat.imageOneUrl); 
//     [imagespost addObject:newmogocat]; 

        [post addObject:category]; 

        [self.maincollectionView reloadData]; 
       } 

      } failure:^(AFHTTPRequestOperation *operation, NSError *error) { 
//     
//    UIAlertView *erroralert = [[UIAlertView alloc] initWithTitle:@"Something Wrong!" message:[NSString stringWithFormat:@"%@", error.localizedDescription] delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil]; 
//    [erroralert show]; 

      }]; 


     } 

    } failure:^(AFHTTPRequestOperation *operation, NSError * responseObject) { 

    }]; 
} 

- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView 
{ 
    return 1; 
} 

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section 
{ 
    return [post count]; 
} 


- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath 
{ 
    CategoryCollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"cellidentifier" forIndexPath:indexPath]; 
// cell.layer.borderWidth = 2.0f; 
    cell.layer.masksToBounds = NO; 
    cell.layer.cornerRadius = 5.0; 
    cell.layer.borderColor = [UIColor lightGrayColor].CGColor; 
    cell.layer.shadowOffset = CGSizeMake(0, 1); 
    cell.layer.shadowRadius = 4.0; 
    cell.layer.shadowColor = [UIColor darkGrayColor].CGColor; 


    [cell addSubview:cell.maintitleLabel]; 

    Categories *cat = [post objectAtIndex:indexPath.row]; 
    [self.maincollectionView reloadInputViews]; 
    cell.maintitleLabel.text = [NSString stringWithFormat:@" %@ ", cat.title]; 
    [cell.maintitleLabel sizeToFit]; 






    NSString *mainstring = [NSString stringWithFormat:@"%@", cat.imageOneUrl]; 
    NSURL *url = [NSURL URLWithString:mainstring]; 
// 
    [cell.mainImageView setImageWithURL:url placeholderImage:nil]; 
// 



    return cell; 
} 

Answer 1

您可以開始加載數據的最早時間是在init方法中。但說實話，大多數情況下，他們在彼此之後得到如此迅速的打電話，你可能甚至不會注意到其中的差異。但是，如果你有興趣，只是怪人它在這裏：

- (id)init 
{ 
    self = [super init]; 
    if (self) 
    { 
     [self loadcategoryData]; 
    } 
    return self; 
} 

此外，我不知道有多少數據你的下載，但如果要加載一個長長的清單，並花費很長的時間，那麼也許你應該考慮做「分頁」（即只下載數據的一個子部分，然後在用戶向下滾動頁面時請求更多）。