How to use performSelector:withObject:afterDelay: with primitive types in Cocoa?

user_102008 0
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The NSObject method performSelector:withObject:afterDelay: allows me to invoke a method on the object with an object argument after a certain time. It cannot be used for methods with a non-object argument (e.g. ints, floats, structs, non-object pointers, etc.).

What is the simplest way to achieve the same thing with a method with a non-object argument? I know that for regular performSelector:withObject:, the solution is to use NSInvocation (which by the way is really complicated). But I don't know how to handle the "delay" part.

Thanks,

objective-c cocoa
13 Answers

Just wrap the float, boolean, int or similar in an NSNumber.

For structs, I don't know of a handy solution, but you could make a separate ObjC class that owns such a struct.

user_414890

Perhaps NSValue, just make sure your pointers are still valid after the delay (ie. no objects allocated on stack).

user_1059290

I know this is an old question but if you are building iOS SDK 4+ then you can use blocks to do this with very little effort and make it more readable:

double delayInSeconds = 2.0;
int primitiveValue = 500;
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC));
dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
    [self doSomethingWithPrimitive:primitiveValue];     
});
user_842900

You Could just use NSTimer to call a selector:

[NSTimer timerWithTimeInterval:1.0 target:self selector:@selector(yourMethod:) userInfo:nil repeats:NO]
user_2466460
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