问iOS Facebook SDK3.1的设置按钮不起作用

EN

if([SLComposeViewController class])
{
    SLComposeViewController *controller = [SLComposeViewController composeViewControllerForServiceType:SLServiceTypeFacebook];
    [controller setInitialText:text];
    [controller addURL:[NSURL URLWithString:encod]];
    [self presentViewController:controller animated:YES completion:Nil];
    //[message release];

    SLComposeViewControllerCompletionHandler myBlock = ^(SLComposeViewControllerResult result)
    {
        NSString *output= nil;
        switch (result)
        {
            case SLComposeViewControllerResultCancelled:
                output= @"Action Cancelled";
                break;
            case SLComposeViewControllerResultDone:
                output= @"Post Succesfull";
                [self displayText:@"done"];
                break;
            default:
                break;
        }

     };
    controller.completionHandler =myBlock;
}

UIActivityViewController *ActivityView = [[UIActivityViewController alloc] initWithActivityItems:Items applicationActivities:nil];