Class Library Type Information/Reflection

[rbulph]

In VB6 I used the TypeLib Information dll (tlbinf32.dll) to find out about the classes contained in a plug-in Class Library. Is that still the best way to do it in .net?

[PlausiblyDamp]

If the dll is written in .Net then you can use reflection (System.Reflection is the namespace) to find out about an assemblies contents.

http://www.xtremedotnettalk.com/showthread.php?t=77697 has a good example of how to use reflection.

[rbulph]

Thanks.

 

How could I store a description with each class and use Reflection to extract this?

[bri189a]

You could find out about the assembly version, possibly the culture, and other things that are assembly specific. You could also findout the types within the assembly, the methods, properties, and attributes of each type in the assembly. If a type has a field named description, you could find that out- but I don't think anybody would do that.

[snarfblam]

If you are the person writing the class then you could supply a System.ComponentModel.DescriptionAttribute for a class and extract that attribute from the DLL with reflection.

[vB]

'Supply a description

<System.ComponentModel.Description("A class that I made.")> _

Public Class My_Class

 

'This function will load and display the description

Public Shared Sub LoadAndDisplayAttribute

Dim ClassType As System.Type = GetType(My_Class)

'Get a list of description attributes

Dim Attributes As Object() = ClassType.GetCustomAttributes( _

GetType(System.ComponentModel.DescriptionAttribute), False)

 

If Attributes.Length > 0 Then

'Only one description attribute may be applied to a class definition,

'so we will assume that our description is Attributes(0)

MessageBox.Show(CType(Attributes(0), System.ComponentModel.DescriptionAttribute).Description)

End If

End Sub

End Class

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