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Raising Events and Throwing Exceptions

I'm creating a custom class and I need some of my methods to raise events or throw custom exceptions. How would I go about doing this? What are the best practices for this? I want everything self-contained in my custom class. Is this possible or advisable?

RonaldBiemans

small example
Public Class mytest
Public Event myevent(ByVal Text As String)

Public Sub myrun()
For x As Integer = 1 To 10
'whatever
Next
RaiseEvent myevent("finished")
End Sub
End Class

Private Sub myeventhandler(ByVal s As String)
MsgBox(s)
End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

Dim y As New mytest
AddHandler y.myevent, AddressOf myeventhandler

y.myrun()
End Sub

xmlnewbie

ASKER

1. So, I can declare these events in the class that I am making?

2. Where is myeventhandler supposed to be placed?

3. Can I really expect people using my class to add "AddHandler y.myevent, AddressOf myeventhandler" to their code just to catch my events? Can't it be raised and handled similar to how, say, the Button1.Click event is raised and handled?

4. What about custom exceptions? Do I need to create a totally different class for that??? That would be odd to me since I also don't think I can expect people using my class to make sure they have my custom exception class.

xmlnewbie

ASKER

Ronald?

RonaldBiemans

Sorry xmlnewbie, Completly forgot about this question :-),

I haven got much time today (I have to work too :-)) but look at this site it explains very well how to build controls (exposing events, properties etc)

http://www.dotnet247.com/247reference/a.aspx?u=http://www.gotdotnet.com/quickstart/winforms/doc/WinFormsCreatingControls.aspx

xmlnewbie

ASKER

Thanks. I'll look at the link. My concerns are stated in a previous post. Also, my question deals with throwing custom exceptions. Any guidance on that?

xmlnewbie

ASKER

Ronald, Any guidance on throwing exceptions? I'm still studying the link on raising events. Thanks.

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RonaldBiemans

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xmlnewbie

ASKER

Ohhhhhhhhhhhh. Now, throwing exceptions makes sense to me. I can make the exception class part of the custom class that I am developing. Meaning, I don't need to have my class users use another separate class just to catch my exceptions.

Still going thru your link.

xmlnewbie

ASKER

What are you supposed to do with Inner in:

Public Sub New(ByVal Message As String, ByVal Inner As Exception)