how do i get the categoryname from fields instead of properties?

Question

User-1982615125 posted

This gets the categoryname from the first property in the Customer object

dim customer as new customer

Dim categoryname As String = CType(TypeDescriptor.GetProperties(customer)(0).Attributes(GetType(CategoryAttribute)), CategoryAttribute).Category

my question

how do i get the categoryname from fields instead of properties?

Answer 1

User475983607 posted

This gets the categoryname from the first property in the Customer object

dim customer as new customer

Dim categoryname As String = CType(TypeDescriptor.GetProperties(customer)(0).Attributes(GetType(CategoryAttribute)), CategoryAttribute).Category

my question

how do i get the categoryname from fields instead of properties?

My best guess is you are trying to fetch information stored in an attribute.

https://docs.microsoft.com/en-us/dotnet/standard/attributes/retrieving-information-stored-in-attributes

Is there anyway you can provide the attribute, class, and expected results?  

Answer 2

User-1982615125 posted

i have already came acros that article.

it doesnt explain how to get the category name from a field. it doesnt cover fields at all.

Answer 3

User475983607 posted

i have already came acros that article.

it doesnt explain how to get the category name from a field. it doesnt cover fields at all.

Like many of your posts, there is not enough context to understand what you're trying to do.  For the second time, post the class source, attribute source, and explain what results you expect.

Answer 4

User-1982615125 posted

i want to get the Category name of a field.

like: myobject.getfields(0).category    <-- extremely simplified fantasy example

The visual studio property window also gives the categories of fields. its the same thing that im trying to do.

Answer 5

User475983607 posted

i want to get the Category name of a field.

like: myobject.getfields(0).category    <-- extremely simplified fantasy example

The visual studio property window also gives the categories of fields. its the same thing that im trying to do.

Maybe this is what you're after.

https://msdn.microsoft.com/en-us/library/system.componentmodel.categoryattribute(v=vs.110).aspx

Answer 6

User-1982615125 posted

ive been there, but it gets the category of properties. not fields

Answer 7

User475983607 posted

ive been there, but it gets the category of properties. not fields

What are you calling a field?  Is "Appearance" what you're looking for?

[Description("The image associated with the control"),Category("Appearance")] 
 public Image MyImage {
    get {
       // Insert code here.
       return image1;
    }
    set {
       // Insert code here.
    }
 }

Answer 8

User-1982615125 posted

what you sent, was a property.

a field is just a variable in the root of an class or structure. for example, Name is a field of Customer. but creationtime is a property of customer

public Class Customer
          Public name as string
          public property CreationTime as datetime
End class

Answer 9

User-1982615125 posted

as you can see, in VB what you made in C#, is a property

<Description("The image associated with the control"), Category("Appearance")>
Public Property MyImage As Image
    Get
       Return image1
    End Get
    Set(ByVal value As Image)

    End Set
End Property

Answer 10

User475983607 posted

fazioliamboina

what you sent, was a property.

a field is just a variable in the root of an class or structure. for example, Name is a field of Customer. but creationtime is a property of customer

public Class Customer
          Public name as string
          public property CreationTime as datetime
End class

I know what a field is but you're questions generally make little no sense and you don't provide code.   So I have to ask clarifying questions. 

Do you have a class with a field named "categoryname" and you want to use reflection to get a this field?

https://msdn.microsoft.com/en-us/library/4ek9c21e(v=vs.110).aspx

Answer 11

User-1982615125 posted

no. i have a field. lets name this field MYFIELD.

and i want to get the category name of MYFIELD

output:

The categoryname of MYFIELD is GLOBAL SETTING

<Category("GLOBAL SETTINGS")> Public MYFIELD As String

Answer 12

User-1982615125 posted

for example, provide me code that extracts the category name 'LAYOUT'  from the field 'Width' from a tablecell object.

Answer 13

User475983607 posted

for example, provide me code that extracts the category name 'LAYOUT'  from the field 'Width' from a tablecell object.

What tablecell?  I give up.  It is abundantly clear from this and previous posts that you are not on the forum for assistance...  Good luck.

Answer 14

User-1982615125 posted

the table cell is just an imaginary context for you to understand what im trying to do. The thing is i dont have a context, i just try to do things that would work in ANY context.

so here is a context to work with: this table cell

https://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.tablecell(v=vs.110).aspx

it has a property called 'Width' and has been categorised 'Layout'. but forget it, because unfortunately my field is not a property

in the mean time. can you make code that extracts the category name from a field?

Answer 15

User-1982615125 posted

how to get the category name from a field?

This works with properties | it extracts the category name of the first (0) field in the Customer object

Dim customer as new customer

Dim catstring As String = CType(TypeDescriptor.GetProperties(Customer)(0).Attributes(GetType(CategoryAttribute)), CategoryAttribute).Category

but how to do this with fields instead of properties? | for example, how to extract the category name 'General settings'  from this 'Field'  field.

Public Class Customer

               <Category("general settings")> Public Field As String

end class

Answer 16

User-1982615125 posted

this does the trick, but i find it kinda hacky

dim customer as new customer

MsgBox(Split(Split(Customer.GetType.GetFields.First.CustomAttributes.Where(Function(c) c.AttributeType = GetType(CategoryAttribute)).First.ToString, """", 2)(1), """", 2)(0))

it exports a CustomattributeData object to a string, and then i just fish the category name out of that string using splitting.

but is there a safer/more straightforward way to do this?

Answer 17

User283571144 posted

Hi fazioliamboina,

According to your description, I suggest you could consider using the System.Reflection's FieldInfo to achive your requirement,

The FieldInfo class contains the information for the fields and we could get the attribute from it.

More details, you could refer to below codes:

        Dim props As FieldInfo() = GetType(Customer).GetFields()

        For Each prop As FieldInfo In props
            Dim attrs As Object() = prop.GetCustomAttributes(True)

            For Each attr As Object In attrs
                Dim authAttr As CategoryAttribute = TryCast(attr, CategoryAttribute)

                If authAttr IsNot Nothing Then
                    Dim propName As String = prop.Name
                    Dim auth As String = authAttr.Category
                End If
            Next
        Next

Result:

Best Regards,

Brando