与Facebook的共享SLComposeViewController：防止完成处理时没有网络可用(

我在我的应用程序（iOS6的）实现的Facebook共享和代码如下。

//完成处理程序

SLComposeViewControllerCompletionHandler __block completionHandler = ^(SLComposeViewControllerResult result) {
    UIAlertView *alert = nil;
    switch(result) {
        case SLComposeViewControllerResultCancelled: {
            alert = [UIAlertView alloc]initWithTitle:@"Cancelled" message:@"Your message wasn't shared" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
            [alert show];
        }
        break;
        case SLComposeViewControllerResultDone: {
            alert = [UIAlertView alloc]initWithTitle:@"Posted" message:@"Your message was posted successfully" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
            [alert show];
        }
        break;
    }
}

//发布至Facebook

if([SLComposeViewController isAvailableForServiceType:SLServiceTypeFacebook]) {
    SLComposeViewController *fbVC = [SLComposeViewController composeViewControllerForServiceType:SLServiceTypeFacebook];
    fbVC.completionHandler = completionHandler;
    [self presentViewController:fbVC animated:YES completion:nil];
}

我测试了以下几种情况：

1. 互联网提供与用户输入的文本和压后
2. 互联网提供与用户输入的文本，并按下了取消
3. 网络不可用，用户输入的文本和压后。

前两部作品，因为他们应该。 在第三种情况下，如预期，我得到警报

"Cannot Post to Facebook" - The post cannot be sent because connection to Facebook failed.

但经过我请按再试，或在提交给我警报视图取消按钮，我得到“发布”警报（完成处理器类型SLComposeViewControllerResultDone被执行）。

如何避免这种情况？

Answer 1:

请检查您是否添加URL以它（SLComposeViewController），它必须是http://www.stackoverflow.com格式化，否则它会继续显示“无法投递到Facebook” -该帖子无法发送，因为连接到Facebook的失败。

HTH

Answer 2:

编辑：嗯，这是简单的修复第三种情况。 我加入苹果公司提供的可达性类（提供下载这里 。）只有被要求的代码如下：

#import "Reachability.h"

- (BOOL)internetConnected {
    Reachability *reachability = [Reachability reachabilityForInternetConnection];
    NetworkStatus networkStatus = [reachability currentReachabilityStatus];
    return !(networkStatus == NotReachable || reachability.connectionRequired); //required for iOS 7 and above
}

... 
...

case SLComposeViewControllerResultDone: {
    if(self.internetConnected) {
        alert = [UIAlertView alloc]initWithTitle:@"Posted" message:@"Your message was posted successfully" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
    } else {
        alert = [UIAlertView alloc]initWithTitle:@"Failed" message:@"Your message was not posted, no internet was available" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
    }
break;

文章来源: Facebook sharing with SLComposeViewController: Prevent completion handler when no internet is available