ios - 错误消息 fbcdn.net urls are not allowed

Question

我正在尝试使用此代码分享帖子：

// Put together the dialog parameters
    NSMutableDictionary *params = [[NSMutableDictionary alloc]init];
    [params setValue:[Campaign sharedInstance].name forKey:@"name" ];
    [params setValue:@"desription" forKey:@"description"];
    [params setValue:picture.facebookPicture.link forKey:@"link"];
    [params setValue:picture.facebookPicture.source forKey:@"picture"];

    // Show the feed dialog
    [FBWebDialogs presentFeedDialogModallyWithSession:nil                                             parameters:params handler:^(FBWebDialogResult result, NSURL *resultURL, NSError *error) {
        if(error) {
            [basicViewController toastMessage:[@"Error sharing on Facebook: " stringByAppendingString:error.localizedDescription]];
        }}];

我收到一个错误，因为图片的来源来自 facebook。我可以做些什么来添加想要的 facebook 图片并仍在使用 fbwebdialogs？