Question

当我在iPad上运行时，我的应用程序出现此错误：

未捕获的异常：CALayer位置包含NaN

相同的代码在iPhone上运行良好。

- (void)mapView:(MKMapView *)mapView didAddAnnotationViews:(NSArray *)views
{
    AnnotationView *aV;

    for (aV in views) {
        // Don't pin drop if annotation is user location
        if ([aV.annotation isKindOfClass:[MKUserLocation class]]) {
            continue;
        }

        // Check if current annotation is inside visible map rect, else go to next one
        MKMapPoint point =  MKMapPointForCoordinate(aV.annotation.coordinate);
        if (!MKMapRectContainsPoint(mapViewResult.visibleMapRect, point)) {
            continue;
        }

        CGRect endFrame = aV.frame;

        // Move annotation out of view
        // I checked here, CGRectEmpty returns true here

        aV.frame = CGRectMake(aV.frame.origin.x, aV.frame.origin.y - self.view.frame.size.height, aV.frame.size.width, aV.frame.size.height);

        // Animate drop
        [UIView animateWithDuration:0.5 delay:0.04*[views indexOfObject:aV] options: UIViewAnimationOptionCurveLinear animations:^{

            aV.frame = endFrame;

            // Animate squash
        }completion:^(BOOL finished){
            if (finished) {
                [UIView animateWithDuration:0.05 animations:^{
                    aV.transform = CGAffineTransformMakeScale(1.0, 0.8);

                }completion:^(BOOL finished){
                    if (finished) {
                        [UIView animateWithDuration:0.1 animations:^{
                            aV.transform = CGAffineTransformIdentity;
                        }];
                    }
                }];
            }
        }];
    }
}

我知道，分配的帧包含NaN值，我使用CGRectEmpty函数进行了检查，并将该帧设置为CGRectZero，但它不起作用。

我从这里得到了这个有效的代码，https://stackoverflow.com/a/7045916/1603234

Backtrace / Debug Log

*** Terminating app due to uncaught exception 'CALayerInvalidGeometry', reason: 'CALayer position contains NaN: [594.947 nan]'
*** First throw call stack:
(
    0   CoreFoundation                      0x048551e4 __exceptionPreprocess + 180
    1   libobjc.A.dylib                     0x034ad8e5 objc_exception_throw + 44
    2   CoreFoundation                      0x04854fbb +[NSException raise:format:] + 139
    3   QuartzCore                          0x01a1be1a _ZN2CA5Layer12set_positionERKNS_4Vec2IdEEb + 190
    4   QuartzCore                          0x01a1bfd9 -[CALayer setPosition:] + 68
    5   QuartzCore                          0x01a1c6df -[CALayer setFrame:] + 799
    6   UIKit                               0x01fbbb4d -[UIView(Geometry) setFrame:] + 302
    7   MyAppName                           0x0026b025 -[ResultMapViewController mapView:didAddAnnotationViews:] + 2133
    8   MapKit                              0x01e0449b -[MKMapView annotationManager:didAddAnnotationRepresentations:] + 272
    9   MapKit                              0x01e3b53c -[MKAnnotationManager updateVisibleAnnotations] + 2052
    10  Foundation                          0x02ed6de7 __NSFireTimer + 97
    11  CoreFoundation                      0x04813ac6 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 22
    12  CoreFoundation                      0x048134ad __CFRunLoopDoTimer + 1181
    13  CoreFoundation                      0x047fb538 __CFRunLoopRun + 1816
    14  CoreFoundation                      0x047fa9d3 CFRunLoopRunSpecific + 467
    15  CoreFoundation                      0x047fa7eb CFRunLoopRunInMode + 123
    16  GraphicsServices                    0x03ccd5ee GSEventRunModal + 192
    17  GraphicsServices                    0x03ccd42b GSEventRun + 104
    18  UIKit                               0x01f60f9b UIApplicationMain + 1225
    19  MyAppName                           0x0001ba3d main + 141
    20  MyAppName                           0x000027e5 start + 53
)
libc++abi.dylib: terminating with uncaught exception of type NSException

Answer 1

OMG！我不知道我能做出这样的＆＃34;愚蠢的＆＃34;错误。

是的，有问题的句子相同的代码在iPhone上运行正常。我收到错误CALayer position contains NaN，因为在我的自定义- (AnnotationView *) mapView:(MKMapView *)mapView viewForAnnotation:(id ) annotation方法中，我正在计算< / p>

annotationView.layer.anchorPoint = CGPointMake(0.5, 1.0 - (diffFromBottom * 1.0)/annotationView.image.size.height);

annotationView.image是空白的，因为我忘记在iPad项目中添加图钉图像。 iPhone代码就在那里。所以它除以零（0）并导致错误。

我放了断点，用NSLog打印了解，

1.0 - (diffFromBottom * 1.0)/annotationView.image.size.height打印了-inf的值。这导致应用程序崩溃。

基本上，如果您按无穷大或零执行除法，则会发生此错误，因此每当您遇到此类错误时，请首先查看执行除法运算的代码。

未捕获的异常：CALayer位置在执行动画时包含NaN

1 个答案: