Reflection question

[neodatatype]

Hi all!

 

A little question on System.Reflection.

 

I know that with the MethodInfo I can get if a method is public or private.

 

But for properties?

PropertyInfo does not contain a IsPublic property!

 

How can I get this information for a property?

 

Thanx

[Volte]

Properties are sort of misleading; there really are no such things as "properties" interally. Properties are just made of up two accessor methods (or one, if it's read/write only) called get_MyProperty and set_MyProperty. You'll need to get both of these and get *their* visibility.

 

Here is a method I used in one of my programs to get the visibility:

Public Shared Function GetPropertyVisiblity(ByVal pi As PropertyInfo) As Integer
       Dim mSetMethod As MethodInfo
       Dim mGetMethod As MethodInfo
       Dim mCheck As MethodInfo

       'If the property is not write-only, get its "Get" method
       If pi.CanRead Then mGetMethod = pi.GetGetMethod(True)

       'If the property is not read-only, get its "Set" method
       If pi.CanWrite Then mSetMethod = pi.GetSetMethod(True)

       'If there is no "set" method, use the "get" method, and vice versa
       If mSetMethod Is Nothing Then
           mCheck = mGetMethod
       ElseIf mGetMethod Is Nothing Then
           mCheck = mSetMethod
       Else
           mCheck = mSetMethod
       End If

       'Get the attributes of the method
       Dim mAttr As MethodAttributes = mCheck.Attributes And MethodAttributes.MemberAccessMask

       'Check its visibility 
       If (mAttr And MethodAttributes.Public) = MethodAttributes.Public Then
           Return 1 'public
       ElseIf (mAttr And MethodAttributes.Family) = MethodAttributes.Family Then
           Return 2 'protected
       ElseIf (mAttr And MethodAttributes.Assembly) = MethodAttributes.Assembly Then
           Return 3 'internal
       ElseIf (mAttr And MethodAttributes.Private) = MethodAttributes.Private Then
           Return 4 'private
       End If
End Function

I changed it a bit for your purposes (mine returned an Enum type specific to my program), but the functionality is there.

[neodatatype]

Here is a method I used in one of my programs to get the visibility:

 

Woah! :)

 

This seems good, I'll try it and I hope it'll work also with fields and methods :)

 

Thanx!

[Nerseus]

Fields are implemented as two properties (which are wrappers for methods as Volte mentioned). In case that helps :)

 

-Ner

[Volte]

What do you mean by that Nerseus? Fields aren't wrappers for anything, they are just class-level variables, and as such, they have their own attributes (Public, Assembly, etc). You can also check to see if the field is an enum item by seeing if the field's DeclaringType is Enum (with fi.DeclaringType.IsEnum). You can use fi.IsLiteral AndAlso fi.IsStatic to check to see if it's a constant.

 

I will be releasing an Object Browser in the near future in the Code Library which acts like the .NET internal Object Browser and it will show how to do all of this.

[neodatatype]

Here is a method I used in one of my programs to get the visibility:

 

Another question.

 

When I enumerate members of an "enum" I get also all the derived ones, such as ToString() ecc...

 

There is a way to get only the "values"?

 

Thanx again

[Volte]

Just retrieve all of the constant fields, instead of all the members.

[neodatatype]

Just retrieve all of the constant fields, instead of all the members.

 

mmmh, good idea.

But how can I know that the object is an enumerator and not a class?

 

(hehe I hope I'm not boring you :-\ )

[neodatatype]

But how can I know that the object is an enumerator and not a class?

 

Ok, it seems to work fine! :)

 

obj.IsEnum and member.IsLiteral

 

Right?

 

Thanks again.

[neodatatype]

Maybe you can tell me how to filter the get_ and set_ members :mad:

 

Bye

[Volte]

Try the .IsSpecialName property of the MethodInfo.