Question

我有2vcs。主要的vc是* ViewController和其他*问题。启动按钮可以很好地将我带到Questions.vc，但当我尝试从Questions.vc返回ViewController.vc时应用程序崩溃了。 Quit按钮在Questions.H中声明，按钮被链接起来，但是一旦我点击并按下退出按钮，应用程序就会崩溃。

打开所有异常断点后。它显示10个断点，其中3个禁用。这些是代码行：问题.H所有这三行

`

-(IBAction)OphthalmicInstruments:(id)sender;

-(IBAction)Lenses:(id)sender;

-(IBAction)Transposition:(id)sender;

`

Questions.M（蓝色箭头指向空格b / t这两行 `

-(IBAction)OphthalmicInstruments:(id)sender{

    Cat1.hidden = YES;

` Question.M蓝线箭头案例2答案3＆amp;案例3错误4

`

      case 2:
            Question.text = [NSString stringWithFormat:@"A tonometer measures:"];
            Right3.hidden = NO;
            Wrong2.hidden = NO;
            Wrong3.hidden = NO;
            Wrong4.hidden = NO;
            Answer1.text = [NSString stringWithFormat:@"Interpupillary distance"];
            Answer2.text = [NSString stringWithFormat:@"Vertex distance"];
            Answer3.text = [NSString stringWithFormat:@"Intraocular pressure"];
            Answer4.text = [NSString stringWithFormat:@"Basecurve"];
            break;
        case 3: 
            Question.text = [NSString stringWithFormat:@"A lens clock measures:"];
            Right4.hidden = NO;
            Wrong2.hidden = NO;
            Wrong3.hidden = NO;
            Wrong4.hidden = NO;
            Answer1.text = [NSString stringWithFormat:@"Interpupillary distance"];
            Answer2.text = [NSString stringWithFormat:@"Vertex distance"];
            Answer3.text = [NSString stringWithFormat:@"Intraocular pressure"];
            Answer4.text = [NSString stringWithFormat:@"Basecurve"];
            break;

` Questions.M行：break＆amp; case 8行都有蓝色箭头

`

        case 7:
        Question.text = [NSString stringWithFormat:@"The power of a lens is measured in    
_____."];
        Right4.hidden = NO;
        Wrong2.hidden = NO;
        Wrong3.hidden = NO;
        Wrong4.hidden = NO;
        Answer1.text = [NSString stringWithFormat:@"Millimeters"];
        Answer2.text = [NSString stringWithFormat:@"Inches"];
        Answer3.text = [NSString stringWithFormat:@"Nanometers"];
        Answer4.text = [NSString stringWithFormat:@"Diopters"];
        break;
    case 8:
        Question.text = [NSString stringWithFormat:@"A lens with a power of 1 Diopter has a focal length of _____."];

`

Answer 1

我创造了一些非常相似的东西并遇到了同样的问题。我所做的是改变了在VC之间来回传递的代码。

因此，我将其更改为首先是我的ViewController.m中的主页Viewcontroller to Questions

- （IBAction为）StartQuiz：（ID）发送方{

Questions *MenuToQuestions = [[Questions alloc] initWithNibName:nil bundle:nil];
MenuToQuestions.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
[self presentViewController:MenuToQuestions animated:YES completion:nil];

}

现在这就是我在Questions.m中的内容

- （IBAction为）回到：（ID）发送方{

[self dismissViewControllerAnimated:NO completion:nil];

}

Answer 2

1）这与xcode有什么关系？答：没什么所以请不要使用那个标签。

2）您的应用不会在return UIApplicationMain(...时崩溃，因为它确实会导致您无法抓住error / exception。要找出它的破坏位置，您需要添加Catch all exceptions。

您可以通过转到xcode中导航控制器的Exceptions部分来执行此操作。

xcode exceptions window

在此处导航后，您会注意到窗口左下角有+。选择此项，这样就会显示另一个带有两个选项的小窗口

Exception options

您需要选择Add Exception Breakpoint

选择此项后，您将看到一个新窗口

All exceptions

您需要做的就是保留默认设置，然后点击Done，除非您想要使用它们。这将使得当抛出异常时它应该引起它崩溃的线或一般区域，以便更容易识别问题。

这可能无法解决您的问题，但距离解决问题又近了一步。当你得到错误的一般区域时，请发表评论，我会更新我的答案，包括如何解决它，如果可以的话。

后退按钮崩溃应用程序

2 个答案: