self.delegate = self; what's wrong in doing that?

问题

self.delegate = self; what\'s wrong in doing that? and what is the correct way of doing it?

Thanks, Nir.

Code:

(UITextField*)initWith:(id)sender:(float)X:(float)Y:(float)width:(float)hieght:(int)textFieldTag { 
    if (self = [super initWithFrame:CGRectMake(X, Y,width, hieght)]) {
        finalText = [[NSMutableString alloc] initWithString:@\"\"];
        senderObject = sender;
        self.textColor = [UIColor blackColor]; 
        self.font = [UIFont systemFontOfSize:17.0]; 
        self.backgroundColor = [UIColor whiteColor]; 
        self.autocorrectionType = UITextAutocorrectionTypeNo;   
        self.keyboardType = UIKeyboardTypeDefault;     
        self.returnKeyType = UIReturnKeyDone; 
        self.clearButtonMode = UITextFieldViewModeWhileEditing;    
        self.tag = textFieldTag;        
        self.delegate = self;    
        [sender addSubview:self];
    }
    return self;
}

Notes: This is a text field, and when I am setting the delegate to another object (self.delegate = mainView) everything works fine, but then I will have to implement the delegate methods in mainView, and I would like to put them in self (a uiTextField class wich I have created). If I am setting self.delegate = self, I do get a textField but the keyboard doesn\'t show up.

回答1:

See this thread

http://www.cocoabuilder.com/archive/cocoa/241465-iphone-why-can-a-uitextfield-be-its-own-delegate.html#241505

Basically, the reason for the "freeze" when you click on your UITextField with itself as a delegate is that respondsToSelector is calling itself -> infinite recursion.

UITextField is unique AFAIK. You can usually use a class as its own delegate with no particular problems. For UITextField you must create an actual delegate (that could, of course, call methods on the UITextField for which it's a delegate. Just be careful to avoid retain loops, even if you're using ARC).

来源：https://stackoverflow.com/questions/1747777/self-delegate-self-whats-wrong-in-doing-that

标签

iphone