Ios Facebook开放图形对象、、can'；t设置其属性

我已成功地将对象及其属性的默认值发布到墙上

我现在需要做的是通过代码手动设置该对象的这些属性

以下是我所做的：

@protocol OGApple<FBOpenGraphAction>

@property (nonatomic, retain) NSString *url;
@property (nonatomic, retain) NSString *title;
@property (nonatomic, retain) NSString *image;
@property (nonatomic, retain) NSString *description;

@end

@protocol OGEatAction<FBOpenGraphAction>

@property (retain, nonatomic) id<OGApple> apple;

@end

方法二：

graphObject.url = @"http://samples.ogp.me/267255650070428";
graphObject.title = @"Mohammad";
graphObject.image = @"https://raw.github.com/fbsamples/ios-3.x-howtos/master/Images/iossdk_logo.png";

然后将对象指定给操作：

id<OGEatAction> action = (id<OGEatAction>)[FBGraphObject graphObject];

action.apple = graphObject;

然后发布请求

[FBRequestConnection startForPostWithGraphPath:@"me/theapp:eat"
                                       graphObject:action
                                 completionHandler:^(FBRequestConnection *connection,
                                                     id result,
                                                     NSError *error) {
                                     // handle the result
                                     if(error)
                                         NSLog(@"%@", error);
                                     else
                                         NSLog(@"%@", result);
                                 }];

请求已成功发布，返回id=XXXXXXXXX

但在我的时间轴上，该对象不接受我传递给它的参数

我是否遗漏了什么或需要服务器上的任何额外配置

提前感谢：）

action.apple = graphObject;

[FBRequestConnection startForPostWithGraphPath:@"me/theapp:eat"
                                       graphObject:action
                                 completionHandler:^(FBRequestConnection *connection,
                                                     id result,
                                                     NSError *error) {
                                     // handle the result
                                     if(error)
                                         NSLog(@"%@", error);
                                     else
                                         NSLog(@"%@", result);
                                 }];