Confused with Events, Delegates and the like in Monotouch - xamarin.ios

Question

I come from a very proficient Windows .NET background and I'm having a go with Monotouch and I am very confused as to how to respond to events. I like to keep things simple and I have read the Montouch tutorials and looked at the examples. What I'm getting confused about is how to respond to events.
Lets say I have ViewController with a UIButton and a UILabel on it. When I press the button I want to change the label to say "Clicked button".
Therefore I could just do the following:
public override void ViewDidLoad () {
base.ViewDidLoad ();
this.btnClickMe.TouchUpInside += (sender, e) => {
this.lblOutput.Text = "Clicked # " + DateTime.Now.ToShortTimeString ();
}
OR alternatively, I could use this approach which I think would serve me better when it comes to responding to buttons pressed in NavigationBars etc.. In IB I Ctrl-Drag to create an Action. I then move the [Action] method to my .cs file and do the following.
[Action ("btnClickMe_TouchUpInside:")]
public void btnClickMe_TouchUpInside (NSObject sender)
{
this.lblOutput.Text = "Clicked # " + DateTime.Now.ToShortTimeString ();
}
What makes it more confusing for me is some UI components have a .delegate member. To which I can an add an event.
Whats the best method or am I getting totally confused? If so is there is a link you can direct me to where I can learn the best practice, the right approach etc..
Many thanks
Mike

Answer 1

For a good introduction, I recommend Xamarin's article on Events, Protocols and Delegates.
As far as your question of wiring up Action Outlets versus hooking events to Referencing Outlets, they have this to say:
The main difference between using .NET events as opposed to
target-actions is that the latter allows you to wire up multiple
controls to a single action method.
So, you might be inclined to use the action approach if you were building a quick & dirty calculator, and pressing the numbers 0-9 all do the same thing-- you can just read the digit from the button. (If you ever used VB to create a control array, you might be familiar with this technique.)
That said, I find my personal preference is to stick with Reference Outlets. It requires less thinking and going back & forth between MonoDevelop and the Interface Builder. I drop in a UISlider & reference it, then I have access to all of its properties & events from the code. So, hooking something later can be done from the code. Many developers have commented that they trend away from using IB...
Getting back to the facts, MonoTouch offers multiple redundant ways to interact with the UI. For those coming from Objective-C, you will find the familiar "Objective-C Delegates" and references to "selectors". Coming from C#, you can often ignore those approaches. But, you should take the time to read that article so you'll be familiar with the language used in Apple documentation. For example, it is important to note the difference between "Objective-C Delegates" and "C# delegates".
Delegates are used for callbacks in iOS similarly to the way .NET uses
events. To make iOS APIs and the way they use Objective-C delegates
seem more like .NET, MonoTouch exposes .NET events in many places
where delegates are used in iOS.
In time, I believe you will find the API flexible and accommodating of .NET patterns. Converting between the NS types and .NET types is often transparent (e.g. from a lambda expression to an NSAction).
Let me know if you need more specific information.
Cheers.