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iPhone: Executing code Just Once at Initiation of Object

开发者 https://www.devze.com 2022-12-20 07:13 出处:网络
Hey everyone, this is an EXTREMELY beginner question, and I\'m somewhat ashamed I don\'t know it already: How can I execute code just once at the implementation of my object?I have an object that\'s o

Hey everyone, this is an EXTREMELY beginner question, and I'm somewhat ashamed I don't know it already: How can I execute code just once at the implementation of my object? I have an object that's of a subclass of UIView I want some code to be executed as soon as everything kicks off, but I'm only able to get code to be executed in response to user input. ARGHH!

I though -(void)viewDidLoad would work, but to no avail...

Any help is, of course, greatly appreciated. I hate not knowi开发者_开发技巧ng something so simple at this point.

Thanks!


The viewDidLoad method is defined on UIViewController, not on UIView, so there's no reason to expect it to be called in a UIView subclass unless you call it yourself.

If you're creating the view in code, you'll want to look at -initWithFrame:. If you're using IB, use -initWithCoder:.


The - (id)init and the - (id)initWithCoder:(NSCoder *)coder methods only gets called once when the view is created. Otherwise you can also use define symbols:

#ifndef HAS_INIT
#define HAS_INIT
  ...
#endif


For the rare occasion I need to do something like this, I create a variable in the header.

BOOL bRunOnce;

Then in the init,

bRunOnce = FALSE; 

Then in the function:

if (bRunOnce == FALSE){
  // do stuff
   bRunOnce = TRUE; 
}
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