Question

我有以下设置使用AFNetworking来调用我的服务器。我使用了我在互联网上找到的一个例子来包含一个完成块，所以我知道通话何时结束。

档案“FCEngine.m”

- (void)fetchBusinessProfile:(NSString *)userID userAccessToken:(NSString *)userAccessToken completion:(void (^)(NSDictionary *json, BOOL success))completion {

/// Validate the user token again the user id.

NSDictionary *parameters = [[NSDictionary alloc]initWithObjectsAndKeys:userAccessToken,@"user_access_token",
                            userID,@"user_id",
                            nil];


AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];

AFHTTPRequestSerializer *serializer = [AFHTTPRequestSerializer serializer];
manager.requestSerializer = serializer;

manager.responseSerializer = [AFJSONResponseSerializer serializerWithReadingOptions:NSJSONReadingAllowFragments];

[manager POST:@"" parameters:parameters progress:nil success:^(NSURLSessionTask *task, id responseObject) {

    NSLog(@"JSON Business Profile: %@", responseObject);

    fetchBusinessProfileCompletion(responseObject, YES);

} failure:^(NSURLSessionTask *operation, NSError *error) {

    //NSLog(@"Error: %@", error);

    NSMutableDictionary *errorResponse = [[NSMutableDictionary alloc] init];

    [errorResponse setObject:@"connection_error" forKey:@"state"];
    [errorResponse setObject:[error localizedDescription] forKey:@"description"];

    fetchBusinessProfileCompletion(errorResponse, YES);

}];

}

- (void)fetchNotifications:(NSString *)userID userAccessToken:(NSString *)userAccessToken completion:(void (^)(NSDictionary *json, BOOL success))completion {

/// Validate the user token again the user id.

NSDictionary *parameters = [[NSDictionary alloc]initWithObjectsAndKeys:userAccessToken,@"user_access_token",
                            userID,@"user_id",
                            nil];


AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];

AFHTTPRequestSerializer *serializer = [AFHTTPRequestSerializer serializer];
manager.requestSerializer = serializer;

manager.responseSerializer = [AFJSONResponseSerializer serializerWithReadingOptions:NSJSONReadingAllowFragments];

[manager POST:@"" parameters:parameters progress:nil success:^(NSURLSessionTask *task, id responseObject) {

    //NSLog(@"JSON: %@", responseObject);

    completion(responseObject, YES);

} failure:^(NSURLSessionTask *operation, NSError *error) {

    //NSLog(@"Error: %@", error);

    NSMutableDictionary *errorResponse = [[NSMutableDictionary alloc] init];

    [errorResponse setObject:@"connection_error" forKey:@"state"];
    [errorResponse setObject:[error localizedDescription] forKey:@"description"];

    completion(errorResponse, YES);

}];


}

以下是我在主视图控制器

上进行调用的方法

- (void)MyMethods {

 [self.fcEngine fetchBusinessProfile:userID userAccessToken:userAccessToken completion:^(NSDictionary *json, BOOL success) {

    /// Response here


}];

[self.fcEngine fetchNotifications:self.userID userAccessToken:self.userAccessToken completion:^(NSDictionary *json, BOOL success) {

       //// Response here

 }];

}

现在的问题是2个调用是一个接一个地进行的，当我获取一个例如“fetchBusinessProfile”两个竞争块都被调用。

我设置错了吗？如果有2个或更多个调用，我只希望为该特定块调用完成，而不是全部调用。

Answer 1

我认为您不了解异步以及完成块。如果您按上述定义进行2次网络呼叫，则可以按任何顺序进行。 completion和fetchBusinessProfile中的fetchNotifications将是不同的完成块... 除非使它们相同。

例如：

 [self.fcEngine fetchBusinessProfile:userID userAccessToken:userAccessToken completion:^(NSDictionary *json, BOOL success) {

    /// Handle response
    // Note calling the SAME completion block
    sameCompletionBlockAlreadyDefined();


}];

[self.fcEngine fetchNotifications:self.userID userAccessToken:self.userAccessToken completion:^(NSDictionary *json, BOOL success) {

    //// Handle response
    // Note calling the SAME completion block
    sameCompletionBlockAlreadyDefined();

 }];

在这种情况下，sameCompletionBlockAlreadyDefined()是一些已定义的块。在这种情况下，每个呼叫的块体确实是，但通过sameCompletionBlockAlreadyDefined汇集到同一个呼叫。您可能会感到困惑，因为completion恰好在您的第一个代码段中被命名为相同。

请注意，您的问题措辞非常差，因此并不完全明确您的意思。

更大的问题是你的目标是什么？您是否只想在结束时调用一个完成块？或者你想要完全不同的完成块？两者都需要不同的技术明确你的目标是什么。

前者是dispatch_group的最佳服务。后者需要不同的完成块。

调度组的一个例子是：

dispatch_group_t group = dispatch_group_create();

dispatch_group_enter(group);

[self.fcEngine fetchBusinessProfile:userID userAccessToken:userAccessToken completion:^(NSDictionary *json, BOOL success) {

    /// Handle response
    dispatch_group_leave(group);


];

self.fcEngine fetchNotifications:self.userID userAccessToken:self.userAccessToken completion:^(NSDictionary *json, BOOL success) {

    //// Handle response
    dispatch_group_leave(group);

}];

dispatch_group_wait(group, DISPATCH_TIME_FOREVER);

// This would be some completion block which means all is done
completion();

一个接一个地调用两个NSURLSessionTask完成块？

1 个答案: