How to create a Custom Routed Event ? WPF c#

Question

I followed this tutorial but I couldn't apply what I learned to my project.

I have a LineGraph object (Dynamic Data Display) and I want to create an event that is raised when the thickness of the LineGraph is equal to 0.

How am I supposed to write it following this tutorial ?

Answer 1

Personally, I usually avoid creating events, preferring instead to create delegates. If there is some particular reason that you specifically need an event, then please ignore this answer. The reasons that I prefer to use delegates are that you don't need to create additional EventArgs classes and I can also set my own parameter types.

First, let's create a delegate:

public delegate void TypeOfDelegate(YourDataType dataInstance);

Now a getter and setter:

public TypeOfDelegate DelegateProperty { get; set; }

Now let's create a method that matches the in and out parameters of the delegate:

public void CanBeCalledAnything(YourDataType dataInstance)
{
    // do something with the dataInstance parameter
}

Now we can set this method as one (of many) handlers for this delegate:

DelegateProperty += CanBeCalledAnything;

Finally, let's call our delegate... this is equivalent to raising the event:

if (DelegateProperty != null) DelegateProperty(dataInstanceOfTypeYourDataType);

Note the important check for null. So that's it! If you want more or less parameters, just add or remove them from the delegate declaration and the handling method... simple.