'NSInvalidArgumentException'/'-[AppDelegate fieldChanged：]：无法识别的选择器已发送到实例

Question

The app terminates with a NSInvalidArgumentException when I use this code and I do not know why:

In my FieldViewController.m I have:

-(IBAction)fieldEntered:(NSString*)sender {
[self.temp resignFirstResponder];
NSString *setFieldEntered;
setFieldEntered = temp.text;
fieldTemp = setFieldEntered;
[(EditViewController *)[[UIApplication sharedApplication] delegate] fieldChanged:(id)sender];

[self dismissModalViewControllerAnimated:YES]; 
}

It terminates on the [(EditViewController *)[[UIApplication sharedApplication] delegate] fieldChanged:(id)sender]; line.

In my EditViewController.h I have -(void)fieldChanged:(id)sender; and in my EditViewController.m file I have:

-(void)fieldChanged:(id)sender {
    [fieldArray insertObject:[FieldViewController fieldEntered] atIndex:[fieldArray count]+1];
}

Please help me figure this one out. Thank you.

Answer 1

从错误中可以看出，UIApplication的委托似乎设置为名为AppDelegate的类的实例，而您将其视为另一个名为EditViewController的类。

Answer 2

That doesn't make sense. May be you forgot to refer to the controller. Should be something like this:

[[[UIApplication sharedApplication] delegate].editViewController fieldChanged:sender];