Question

我创建了一个按钮并在运行时添加了它的动作。整个视图在运行时创建。在点击时调用操作saveUserProfileSetting会导致应用"NSInvalidArgument: Unrecornized selector sent to a instance崩溃。当代码存在时，它工作正常另一堂课。我试图为它创建一个新类，它崩溃了。

@interface LASplashViewer : NSObject

        +(void) showSplashScreen;
        +(void) dismissSplashScreen;

        @end

    (void) showSplashScreen
    {
        UIView *mainScreen = [[[UIApplication sharedApplication]delegate]window];

        UIView *windowBlocker = [[UIView alloc]initWithFrame:mainScreen.frame];
        windowBlocker.tag = 999;
        windowBlocker.backgroundColor = [UIColor clearColor];

    UIButton *saveButton = [[UIButton alloc]initWithFrame:CGRectMake(200, 430, 420, 30)];
        [saveButton setTitle:@"Save" forState:UIControlStateNormal];
        [saveButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
        [saveButton addTarget:self action:@selector(saveUserProfileSetting) forControlEvents:UIControlEventTouchUpInside];

   UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(165, 200, 450, 480)];

        imageView.layer.cornerRadius=10;
        imageView.layer.masksToBounds = YES;
        [windowBlocker addSubview:imageView];
    [imageView addSubview:saveButton];
     imageView.userInteractionEnabled = true;

        [mainScreen addSubview:windowBlocker];
    }

    -(void) saveUserProfileSetting
    {
        // TODO: if validation is successful save the below data. and dismiss the splash screen.
        NSUserDefaults *userSettings = [[NSUserDefaults alloc] init];

        [userSettings setObject:fullName.text forKey:@"name_pref"];
        NSLog(@"%@fullname" , fullName);
        [userSettings setObject:jobTitle.text forKey:@"title_pref"];
        [userSettings setObject:streetName.text forKey:@"street_name_pref"];
        [userSettings setObject:suburbs.text forKey:@"suburb_pref"];
        [userSettings setObject:postCode.text forKey:@"postcode_pref"];
        [userSettings setObject:phoneNum.text forKey:@"phone_no_pref"];
        [userSettings setObject:fax.text forKey:@"fax_pref"];
        [userSettings setObject:mobileNumber.text forKey:@"mobile_no_pref"];
        [userSettings setObject:email.text forKey:@"email_pref"];
        [userSettings synchronize];
    }

调用方法是Show is in another class - // HomeViewController。

(void)viewDidLoad
{
    [super viewDidLoad];
    if ([[NSUserDefaults standardUserDefaults] boolForKey:@"isFirstLaunch"])
    {
        // app already launched
        [[NSUserDefaults standardUserDefaults]synchronize];

    }
    else
    {
        [[NSUserDefaults standardUserDefaults]setBool:YES forKey:@"isFirstLaunch"];
        [[NSUserDefaults standardUserDefaults]synchronize];
        // call this method only for the first load.
        //[self performSelector:@selector() withObject:nil afterDelay:0.5];
        [self performSelector:@selector(saveProfile) withObject:Nil afterDelay:0.5];
        }
}
-(void) saveProfile
{
    [LASplashViewer showSplashScreen];
}

日志：

由于未捕获的异常'NSInvalidArgumentException'而终止应用程序，原因：'+ [LASplashViewer saveUserProfileSetting]：无法识别的选择器发送到类0x2a4dc'

请指导我。感谢

Answer 1

[LASplashViewer saveUserProfileSetting]崩溃，因为它不是静态函数。将您的功能设为

1）+ (void)saveUserProfileSetting { }

2）或致电

LASplashViewer *viewer = [[LASplashViewer alloc] init];
[viewer saveUserProfileSetting];

Answer 2

看起来你从类方法

调用实例选择器

LASplashViewer有类方法showSplashScreen，您可以在其中调用实例方法saveUserProfileSetting

要解决问题，请尝试制作saveUserProfileSetting类方法（将-替换为+）

Answer 3

+(void) showSplashScreen;是一种类方法，您可以从中为按钮

设置操作

[saveButton addTarget:self action:@selector(saveUserProfileSetting) forControlEvents:UIControlEventTouchUpInside];

此处目标是self。在类方法中self引用它自己的Class而不是实例。所以这里方法的目标是LASplashViewer而不是它的实例。您的按钮需要类+(void)saveUserProfileSetting之类的类方法。它没有找到具有此类名称的类方法。它崩溃了。我希望你理解根本原因。

解决方案是将方法作为类方法

+ (void)saveUserProfileSetting

应用程序崩溃按钮单击操作iOS

3 个答案: