Question

我正在使用segue的代码：

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(UIButton *)sender
{
    menuVC *menuview = [segue destinationViewController];
    CGPoint centerOfButton = [sender.superview convertPoint:sender.center toView:nil];

    [self.circularTransitionHandler transitionWithDestinationViewController:menuview initialTransitionPoint:centerOfButton];
}

App崩溃了：

由于未捕获的异常终止应用＆＃39; NSInvalidArgumentException＆＃39;，原因：＆＃39; - [UIBarButtonItem superview]：无法识别的选择器发送到实例0x7ffb74293b10 ＆＃39;

Answer 1

您是否尝试访问点击按钮？因此，当您尝试让按钮超级查看时，应用程序会崩溃。很遗憾，UIBarButtonItem没有superview财产。您需要使用.view的{{1}}。

请更新您的代码：

UIBarButtonItem

请参阅我已更改的参数类型。

Answer 2

`UIBarButtonItem` does not extend `UIView` thus it has no frame property. 
We can get center point of button like this:


    - (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(UIBarButtonItem *)sender
    {
        menuVC *menuview = [segue destinationViewController];
        UIView *barView = [sender valueForKey:@"view"];
        if (barView) {
        CGRect buttonFrame = [barView convertPoint: barView.bounds toView:self.view];   

        CGPoint centerOfButton = CGPointMake(buttonFrame.origin.x + buttonFrame.size.width/2,
                                           buttonFrame.origin.y + buttonFrame.size.height/2);

        [self.circularTransitionHandler transitionWithDestinationViewController:menuview 
                                                      initialTransitionPoint:centerOfButton];
         }
    }

[UIBarButtonItem superview]：发送到实例的无法识别的选择器

2 个答案: