ios facebook用户信息

Question

你能帮我如何获得用户信息吗？

  NSString *name;
[FBRequestConnection startForMeWithCompletionHandler:^(FBRequestConnection *connection, id result, NSError *error)
    {
        if (!error)
        {
            // Success! Include your code to handle the results here
           name = [result objectForKey:@"first_name"]; // Error!!! how to get data from this handler
        }
        else
        {
            // An error occurred, we need to handle the error
            // See: https://developers.facebook.com/docs/ios/errors
        }

    }];

上面描述的代码-异步？如何使其同步？给我讲讲机械装置或者告诉我在哪里读。谢谢!

Answer 1

您可以在这个网站上阅读关于Facebook 的所有内容：https://developers.facebook.com。

它们不提供同步API，我甚至不知道您为什么需要它。但如果你真的这么做了，你可以做些解决办法。见执行情况：

__block id result = nil;
dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);

[FBRequestConnection startForMeWithCompletionHandler:^(FBRequestConnection *connection, id theResult, NSError *error) {
    result = theResult;
    dispatch_semaphore_signal(semaphore);    // UPDATE: dispatch_semaphore_wait call was here, which is wrong
}];

dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
NSLog(@"%@", result);// this code will be launched after you've received response from Facebook

结果符合FBGraphUser协议。因此，如果它不包含first_name键的值，用户就不会指定它。您可以在调试器中打印结果并查看它是什么。

Answer 2

您可以使用其他方法来解决您的问题: 1)将名称设为属性：__block NSString *name 2)将您需要执行的代码移动到单独的方法，如下所示：

- (void) methodWithComplitionHandler
{
name = nil;
[FBRequestConnection startForMeWithCompletionHandler:^(FBRequestConnection *connection, id result, NSError *error)
{
        if (!error)
        {
           name = [result objectForKey:@"first_name"]; 
        }
        else
        {
        }
}];
[self futherProcessMethod];
}

- (void) furtherProcessMethod
{
if (self.name == nil)
    {
        [self performSelector:@selector(furtherProcessMethod) withObject:nil afterDelay:3.0]; // here set appropriate delay
    }
    else
    {
      // do some with name;
    }
}

Answer 3

正如我在前面的回答中所阐明的，您需要在“answer”语句中使用name。请调试以获得更多的理解。所以我们有：

- (void) SetUserData
{
    [FBRequestConnection startForMeWithCompletionHandler:^(FBRequestConnection *connection, id result, NSError *error)
    {
        if (!error)
        {
            self.first_name  = [result objectForKey:@"first_name"];
        }
        else
        {
        }
    }];
    [self furtherProcessMethod];

}


- (void) furtherProcessMethod
{
    if (self.first_name == nil)
    {
        [self performSelector:@selector(furtherProcessMethod) withObject:nil afterDelay:30.0]; // here set appropriate delay
    }
    else
    {
        NSLog(@"first_name: %@", self.first_name); 
    }
}