iphone - UITableView 中的 UIGestureRecognizer - 滚动后崩溃？

Question

我有一个带有自定义单元格的 UITableView。每个单元格内有 2 个 View 。每个 View 都有一个附加的 UIGestureRecognizer 来处理点击事件。当点击 View 时，我向 UINavigationController 发送一条消息以推送详细信息 View 。在我实际滚动表格之前，这种情况效果很好。滚动表格后，当用户点击单元格内的 View 之一时，应用程序会崩溃。例如，我可以加载应用程序，单击第二个单元格中的 View ，然后将详细 View 正确推送到屏幕上。从那里，我导航回到表格，滚动到底部，回到顶部，然后点击相同的 View 。从那里开始，应用程序崩溃并出现无法识别的选择器错误。这是我的手势设置(在 viewDidLoad 中):

UITapGestureRecognizer *recognizer = [[UITapGestureRecognizer alloc] initWithTarget:self 
                                                                          action:@selector(handleTap:)];
[self.view addGestureRecognizer:recognizer];
recognizer.delegate = self;
[recognizer release];

这是调用的方法:

-(void)handleTap:(UITapGestureRecognizer *)sender{
    NSLog(@"Handling tap on ArticleTileViewController");
    ArticleViewController *vc = [[ArticleViewController alloc] initWithArticleData:self.articleDataArray];
    PROJECTAppDelegate *appDelegate = (PROJECTAppDelegate *)[UIApplication sharedApplication].delegate;

    [appDelegate.navController pushViewController:vc animated:YES]; 
}[appDelegate.navController pushViewController:vc animated:YES]; 
    }

最后，这是我在控制台中获得的堆栈跟踪:

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFType handleTap]: unrecognized selector sent to instance 0x607ba30'
*** Call stack at first throw:
(
    0   CoreFoundation                      0x02839b99 __exceptionPreprocess + 185
    1   libobjc.A.dylib                     0x0298940e objc_exception_throw + 47
    2   CoreFoundation                      0x0283b6ab -[NSObject(NSObject) doesNotRecognizeSelector:] + 187
    3   CoreFoundation                      0x027ab2b6 ___forwarding___ + 966
    4   CoreFoundation                      0x027aae72 _CF_forwarding_prep_0 + 50
    5   UIKit                               0x0057f060 -[UIGestureRecognizer _updateGestureWithEvent:] + 727
    6   UIKit                               0x0057b8bf -[UIGestureRecognizer _delayedUpdateGesture] + 47
    7   UIKit                               0x00580152 _UIGestureRecognizerUpdateObserver + 637
    8   UIKit                               0x00581464 _UIGestureRecognizerUpdateGesturesFromSendEvent + 51
    9   UIKit                               0x0032a844 -[UIWindow _sendGesturesForEvent:] + 1292
    10  UIKit                               0x003263bf -[UIWindow sendEvent:] + 105
    11  UIKit                               0x00309cb4 -[UIApplication sendEvent:] + 447
    12  UIKit                               0x0030e9bf _UIApplicationHandleEvent + 7672
    13  GraphicsServices                    0x02f07822 PurpleEventCallback + 1550
    14  CoreFoundation                      0x0281aff4 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 52
    15  CoreFoundation                      0x0277b807 __CFRunLoopDoSource1 + 215
    16  CoreFoundation                      0x02778a93 __CFRunLoopRun + 979
    17  CoreFoundation                      0x02778350 CFRunLoopRunSpecific + 208
    18  CoreFoundation                      0x02778271 CFRunLoopRunInMode + 97
    19  GraphicsServices                    0x02f0600c GSEventRunModal + 217
    20  GraphicsServices                    0x02f060d1 GSEventRun + 115
    21  UIKit                               0x00312af2 UIApplicationMain + 1160
    22  PROJECT                                0x00002459 main + 121
    23  PROJECT                                0x000023d5 start + 53
    24  ???                                 0x00000001 0x0 + 1
)
terminate called after throwing an instance of 'NSException

'

编辑:经过一段时间的测试后，我确定只有当时屏幕上可见的 View 才会触发该事件。其他一切都会因上述错误而崩溃。可能与this有关未回答的问题？

这是我的 header 声明(为了清楚起见，省略了 iVar 和属性:

@interface ArticleTileViewController : UIViewController<UIGestureRecognizerDelegate> {

}

-(void)handleTap:(UITapGestureRecognizer *)sender;

Answer 1

基本上，这个问题意味着您正在向一个根本无法识别该消息的对象发送消息，即缺少该方法。

您的选择器创建不正确，它应该是:

UIGestureRecognizer *recognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTap:)];

和

- (void) handleTap:(UITapGestureRecognizer *)sender {

--更新--

recognizer.delegate = self;

很抱歉问这个问题，但是您确定“self”实际上具有方法handleTap:吗？