Objective c 为什么要“得到”；目标C方法的预期选择器“；错误

我有以下代码：

@class GADBannerView,GADRequest;

@interface BT_viewController : UIViewController <UIAlertViewDelegate, 
                                                ADBannerViewDelegate,
                                                UIAccelerometerDelegate,
                                                MFMailComposeViewControllerDelegate,
                                                MFMessageComposeViewControllerDelegate,
                                                GADBannerViewDelegate>{
    BT_item *screenData;
    UIView *progressView;
    GADBannerView *bannerView_;
    /* iAd Views */
    UIView *adView;
    ADBannerView *adBannerView;
    BOOL adBannerViewIsVisible;
    BOOL hasStatusBar;
    BOOL hasNavBar;
    BOOL hasToolBar;

}



@property (nonatomic, retain) BT_item *screenData;
@property (nonatomic, retain) UIView *progressView;
@property (nonatomic, retain) UIView *adView;
@property (nonatomic, retain) ADBannerView *adBannerView;
@property (nonatomic) BOOL adBannerViewIsVisible;
@property (nonatomic) BOOL hasStatusBar;
@property (nonatomic) BOOL hasNavBar;
@property (nonatomic) BOOL hasToolBar;

-(id)initWithScreenData:(BT_item *)theScreenData;


-(void)showProgress;
-(void)hideProgress;
-(void)navLeftTap;
-(void)navRightTap;
-(void)showAudioControls;
-(void)showAlert:(NSString *)theTitle theMessage:(NSString *)theMessage alertTag:(int)alertTag;
-(void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex;

//iAd methods...
-(void)createAdBannerView;
-(void)resizeAdView;
-(void)showHideAdView;
-(void)bannerViewDidLoadAd:(ADBannerView *)banner;
-(void)bannerView:(ADBannerView *)banner didFailToReceiveAdWithError:(NSError *)error;

//shake capture...
-(void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event;

//message compose delegate methods...
-(void)messageComposeViewController:(MFMessageComposeViewController *)controller didFinishWithResult:(MessageComposeResult)result;
-(void)mailComposeController:(MFMailComposeViewController*)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError*)error;



//rotation methods...
-(BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation;
-(void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration;
-(void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation;

@property(nonatomic, strong) GADBannerView *bannerView;
- {GADRequest *}createRequest;

@end

它给出了一个错误：“Objective-C方法的预期选择器” 但是，如果我删除了上面的代码，就可以了。 你能找出这里的错误吗？抱歉，因为我是新手，所以我对错误消息的含义很困惑。

---

谢谢。

我相信您正在尝试声明一个实例方法。更改如下

- (GADRequest *)createRequest; //To This

- {GADRequest *}createRequest; //From this

---

我相信您正在尝试声明一个实例方法。更改如下

- (GADRequest *)createRequest; //To This

- {GADRequest *}createRequest; //From this

---

您使用了大括号而不是圆括号。我不是说这是您的问题，但我从未见过语法

-{type*}selectorName之前。通常我看到的是
-（type*）selectorName（用括号代替大括号）。我的错！是的，我的眼睛真的有问题。谢谢你的认可。我如何才能将您的评论标记为我的答案？您使用了大括号而不是括号。我不是说这是您的问题，但我从未见过语法
-{type*}selectorName之前。通常我看到的是
-（type*）selectorName（用括号代替大括号）。我的错！是的，我的眼睛真的有问题。谢谢你的认可。我怎样才能将你的评论标记为我的答案？是的，这是正确的答案！括号是这里的问题，谢谢！是的，这是正确的答案！括号是这里的问题，谢谢！