Unity Coding Tips Part 1: Events and Delegates

The first tutorial in a series aimed at showing some of the more esoteric features available to Unity developers. In this tutorial, we cover the basics of events and delegates. You will learn some simple techniques to make your code a lot more coherent and easier to manage.

This directly relates to our plugins (http://prime31.com/unity), many of which employ events for dispatching asynchronous operations.

• Category

  Howto & Style

[St4rdog]

This seems similar to "CSharpMessenger Extended" (google it). Other than performance is there any reason it's better? I notice for one thing you will get AutoComplete for the event name, instead of having to type a string.

[prime31studios]

its similar but the key difference is that native events are associated with an object whereas the Messenger Extended is a string based publisher/subscriber system. Events will be faster due to skipping the initial string match.

[Tiziano Cirillo]

Great tutorial, practical and to the point. Thanks!

I found some generic information about this topic online but your example did it for me, will be using events/delegates from today :) - please do more :) c#/Unity :)

QUESTION: In term of performance on iOS, are events/delegates (with maybe quite a few events and listeners in a scene...) good to use or is there some performance issue compared to use some other solution to do the same things?

[prime31studios]

performance will be excellent on mobile. Events are WAY faster than SendMessage and will beat out any alternatives (like subscriber/message solutions).

[lucidskater]

any tips for learning from scratch, i cant seem to find a good tutorial for someone who doesnt know how any of it works

[prime31studios]

a quick web search will get you literally thousands of C# tutorials for beginners. There are also tons of books as well.

[prime31studios]

Many thanks for including your opinion just as we did in the video. We are making tutorial videos and thus would like those watching to be using the best tool. The advantages of C# over JS are concrete and there are many of them but that is a discussion too large for here. Some advantages are:

- TONS of C# learning/documentation resources

- language features that are not available in JS

- no sneaky compiled code (look at compiled output of JS transform.position.x = 3 as an example)

[Sinister Rainbow]

This is by far the best tut i've seen on the topic i've seen in looking around for the last hour. For someone coming to Unity/C# from other game engines this satisfies..

[dylophosaurus]

would you mine clarifying on "abstracting input" please? thanks :)

[Jamie Lowes]

Thanks for this! Totally didn't know about events until I saw them in the Prime31 GameCenter plugin for Unity this morning. Now it's all working. SuperInternetHighFive™!! :D

Keep up the good work!! :D

[Mike Desaro]

It isn't too performance heavy but Input is already global so it doesn't make much sense. If you are abstracting input (which is required for mobile + desktop) then it makes more sense to use an event.

[n3v4k]

Would it be a good practice to notify other GameObjects about the value of (for example) Input.GetAxis() using an event inside the Update() funciton? or it is too performance heavy to fire events at every frame?

[Mike Desaro]

A static variable is absolutely not a replacement for an event.

[deltamish]

Nice tutorial.but you can achieve same effect by just declaring a static variable right or am i missing something here(Did i sound rude there if yes i ma really sorry)

[oioichuck]

Thanks for this tutorial. Extremely useful.

[kang hoo]

Thanks you very much.i hope it have more example ....

[Patrick Davis]

I just stumbled on this from the iTween website, and I wanted to thank you guys for putting this out here. Events are something I've struggled with in other languages and being new to C# having a clear discussion of what is a very elegant solution is great. Thank you!