ios - 使用 iOS 8.2 "unrecognized selector sent to instance"在 Facebook 中邀请 friend 的应用程序

Question

我按照 facebook 文档从这里开发邀请 friend 到 ios 应用程序:App Invites for iOS ...这是我的代码:

    @implementation ViewController  
    FBSDKAppInviteContent *content;
    - (void)viewDidLoad
    {
        [super viewDidLoad];
        // Do any additional setup after loading the view, typically from a nib.

        content =[[FBSDKAppInviteContent alloc] initWithAppLinkURL:[NSURL URLWithString:@"https://fb.me/1569122770021958"]];
        //optionally set previewImageURL
        content.previewImageURL = [NSURL URLWithString:@"http://www.jpl.nasa.gov/spaceimages/images/mediumsize/PIA17011_ip.jpg"];
     }

然后我定义了一个 Action 按钮如下:

- (IBAction)InviteFriends:(id)sender {
    // present the dialog. Assumes self implements protocol `FBSDKAppInviteDialogDelegate`
    [FBSDKAppInviteDialog showWithContent:content delegate:sender];    
}

但是我收到如下错误:

2015-04-30 19:09:06.850 LoopApp[6338:120645] -[UIButton appInviteDialog:didCompleteWithResults:]: unrecognized selector sent to instance 0x7fbdd870f9d0
2015-04-30 19:09:06.852 LoopApp[6338:120645] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UIButton appInviteDialog:didCompleteWithResults:]: unrecognized selector sent to instance 0x7fbdd870f9d0'

它说我还没有定义 appInviteDialog:didCompleteWithResults: 所以我添加了这个方法如下:

- (void) appInviteDialog: (FBSDKAppInviteDialog *)appInviteDialoge didFailWithError:(NSError *)error
{

    NSLog(@"Session connection failed with error %@",[error self]);
}

我可以执行所有步骤来选择我的 friend ，当我按下按钮分享它时，它会分享，但当它想要返回到应用程序崩溃时，它会给我与上面相同的错误。如果有人能帮助我解释为什么会这样，我将不胜感激。

 -[UIButton appInviteDialog:didCompleteWithResults:]: unrecognized selector sent to instance 0x7fabc3dbb840
2015-04-30 19:23:29.305 LoopApp[6423:125823] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UIButton appInviteDialog:didCompleteWithResults:]: unrecognized selector sent to instance 0x7fabc3dbb840'
*** First throw call stack:
(
    0   CoreFoundation                      0x000000010ed0ea75 __exceptionPreprocess + 165
    1   libobjc.A.dylib                     0x000000010e5febb7 objc_exception_throw + 45
    2   CoreFoundation                      0x000000010ed15d1d -[NSObject(NSObject) doesNotRecognizeSelector:] + 205
    3   CoreFoundation                      0x000000010ec6d9dc ___forwarding___ + 988
    4   CoreFoundation                      0x000000010ec6d578 _CF_forwarding_prep_0 + 120
    5   LoopApp                             0x000000010dfb71e1 -[FBSDKAppInviteDialog _invokeDelegateDidCompleteWithResults:] + 297
    6   LoopApp                             0x000000010dfb70a5 -[FBSDKAppInviteDialog _handleCompletionWithDialogResults:error:] + 67
    7   LoopApp                             0x000000010dfb6ed9 __28-[FBSDKAppInviteDialog show]_block_invoke + 131
    8   LoopApp                             0x000000010df92f51 -[FBSDKApplicationDelegate applicationDidBecomeActive:] + 194
    9   CoreFoundation                      0x000000010ecde7fc __CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ + 12
    10  CoreFoundation                      0x000000010ebde204 _CFXNotificationPost + 2484
    11  Foundation                          0x000000010e158df8 -[NSNotificationCenter postNotificationName:object:userInfo:] + 66
    12  UIKit                               0x000000010f33bfc8 -[UIApplication _stopDeactivatingForReason:] + 363
    13  UIKit                               0x000000010f350ea2 -[UIApplication _handleNonLaunchSpecificActions:forScene:withTransitionContext:] + 2648
    14  FrontBoardServices                  0x0000000112831243 __31-[FBSSerialQueue performAsync:]_block_invoke + 16
    15  CoreFoundation                      0x000000010ec43c7c __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ + 12
    16  CoreFoundation                      0x000000010ec399c5 __CFRunLoopDoBlocks + 341
    17  CoreFoundation                      0x000000010ec39785 __CFRunLoopRun + 2389
    18  CoreFoundation                      0x000000010ec38bc6 CFRunLoopRunSpecific + 470
    19  GraphicsServices                    0x0000000113230a58 GSEventRunModal + 161
    20  UIKit                               0x000000010f341580 UIApplicationMain + 1282
    21  LoopApp                             0x000000010df88f93 main + 115
    22  libdyld.dylib                       0x00000001114ff145 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb) 

Answer 1

问题是您将按钮设置为 FBSDKAppInviteDialog 的委托(delegate)。 UIButton 不符合 FBSDKAppInviteDialogDelegate 协议(protocol)，因此崩溃。

要解决此问题，请更改您的代码，使委托(delegate)为 nil 或 self(如果 self 符合 FBSDKAppInviteDialogDelegate 协议(protocol)):

- (IBAction)InviteFriends:(id)sender {

    [FBSDKAppInviteDialog showWithContent:content delegate:self];
}