iOS：从自定义方法向表格视图添加数据

Question

我有一个iPhone应用程序使用OAuth连接到服务器。成功时，它从服务器获取用户。再次，成功后，它会向填充表视图的对象数组添加一个项目。下面是执行此代码：

- (void)setEditing:(BOOL)editing animated:(BOOL)animated 
{ 
    if (editing) { 
     [super setEditing:YES animated:YES]; 

     self.backButton = self.navigationItem.leftBarButtonItem; 

     UIBarButtonItem *leftButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(signInWithCatapult)]; 
     self.navigationItem.leftBarButtonItem = leftButton; 
    } else { 
     [super setEditing:NO animated:YES]; 

     self.navigationItem.leftBarButtonItem = self.backButton; 
    } 
} 

- (void)signInWithCatapult 
{ 
    [self signOut]; 

    GTMOAuth2Authentication *auth = [self catapultAuthenticaiton]; 
    NSURL *authURL = [NSURL URLWithString:@"https://oauth.lvh.me:3000/oauth/authorize"]; 
    GTMOAuth2ViewControllerTouch *viewController; 
    viewController = [[GTMOAuth2ViewControllerTouch alloc] initWithAuthentication:auth 
                   authorizationURL:authURL 
                   keychainItemName:kCatapultKeychainItemName 
                     delegate:self 
                   finishedSelector:@selector(viewController:finishedWithAuth:error:)]; 

    [[self navigationController] pushViewController:viewController animated:YES]; 
} 

- (GTMOAuth2Authentication *)catapultAuthenticaiton 
{ 
    NSURL *tokenURL = [NSURL URLWithString:kDoorkeeperTokenURL]; 
    NSString *redirectURI = @"https://catapultcentral.com/iOSClientCallback"; 

    GTMOAuth2Authentication *auth; 

    auth = [GTMOAuth2Authentication authenticationWithServiceProvider:@"Catapult Central" 
                  tokenURL:tokenURL 
                  redirectURI:redirectURI 
                  clientID:kDoorkeeperClientID 
                 clientSecret:kDoorkeeperClientSecret]; 

    return auth; 
} 

- (void)signOut 
{ 

} 

- (void)viewController:(GTMOAuth2ViewControllerTouch *)viewController 
     finishedWithAuth:(GTMOAuth2Authentication *)auth 
       error:(NSError *)error 
{ 
    if (error != nil) { 
#if DEBUG 
     NSLog(@"ERROR: %@", error); 
#endif 
    } else { 
     NSURL *url = [NSURL URLWithString:@"https://api.lvh.me:3000/api/users/me"]; 
     NSURLRequest *request = [NSURLRequest requestWithURL:url]; 
     GTMHTTPFetcher *fetcher = [GTMHTTPFetcher fetcherWithRequest:request]; 
     [fetcher setAuthorizer:auth]; 
     [fetcher beginFetchWithDelegate:self didFinishSelector:@selector(currentUserFetcher:finishedWithData:error:)]; 
    } 
} 

- (void)currentUserFetcher:(GTMHTTPFetcher *)fetcher 
      finishedWithData:(NSData *)data 
        error:(NSError *)error 
{ 
    if (error != nil) { 
#if DEBUG 
     NSLog(@"ERROR: %@", error); 
#endif 
    } else { 
     NSLog(@"Before: %@", self.accounts); 
     [self.tableView beginUpdates]; 
     [self.accounts addObject:@"Success!!!"]; 
     [self.tableView endUpdates]; 
//  [self.tableView reloadData]; 
     NSLog(@"After %@", self.accounts); 
    } 
} 

它在currentUserFetcher:finishedWithData:error:的方法，我的对象添加到self.accounts可变数组。现在，如果我用这个代码，它不工作：

[self.tableView beginUpdates]; 
[self.accounts addObject:@"Success!!!"]; 
[self.tableView endUpdates]; 

它无法在与以下错误消息的行[self.tableView endUpdates];：

2013-03-28 08:56:21.040 Catapult for iOS[55012:c07] *** Assertion failure in -[UITableView _endCellAnimationsWithContext:], /SourceCache/UIKit_Sim/UIKit-2380.17/UITableView.m:1054 

而且在endUpdates线，Xcode是抱怨说Thread 1: breakpoint 1.3。现在，如果我用这个代码，它正常工作：

[self.accounts addObject:@"Success!!!"]; 
[self.tableView reloadData]; 

现在我怀疑它是失败的，因为我添加对象到self.accounts实例变量，但我真的不增加该小区。所以我的问题是：如何从currentUserFetcher:finishedWithData:error:方法添加单元格到tableView？

Answer 1

如果你只是重写此方法：

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath; 

调用[UITableView的reloadData]应该只是工作本身了。 UITableViewController只会询问那里的数据量（单元格）（使用“tableView：numberOfRowsInSection：”），并使用第一种提到的方法向每个indexPath请求单元格。