CODEWITHSUNDEEP
vb.net
paulopulus
paulopulus

Reputation: 221

How to declare a global variable with multiple properties?

I want to use a variable that's in the scope of all my project, what's a good way to accomplish this?

public User as (some type)
(
 var (sometype)
 var2 (sometype)
)

Example:

If User.name = "ADMIN" Then
  otherForm.Caption = User.name
  otherForm.Show
End If

Upvotes: 1

Views: 2408

Answers (4)

Douglas Barbin
Douglas Barbin

Reputation: 3615

If you are trying to have a "settings" class like some have suggested, you probably want to look at the My.Settings or My.Resources namespaces for VB .Net

You would end up with something like:

If User.name = My.Settings.Admin Then
   otherForm.Caption = User.name
   otherForm.Show
End If

Is this what you are trying to do?

Your other option is to use a module or a "Public NotInheritable" class with a private constructor, with public properties or constants. Like this:

Public NotInheritableClass ProjectSettings

   Public Const Admin as String = "ADMIN"
   Public Const Whatever as Decimal = 3.14D

   Private Sub New()
   End Sub

End Class

Then you could have:

If User.name = ProjectSettings.Admin Then
   otherForm.Caption = User.name
   otherForm.Show
End If

I like these solutions a little better because there is no way that you can instantiate the settings class.

If you just want your User class to be globally accessible (which implies there is only one given User at a time), then you could do something similar with the User class.

EDIT: Your User class would look like:

Public NotInheritableClass User

   Public Const Name as String = "Some Name"
   Public Property YouCanChangeThisProperty as String = "Change Me"

   Private Sub New()
   End Sub

End Class

To use it:

User.YouCanChangeThisProperty = "Changed"
MessageBox.Show("User name: " & User.Name & "; the other property is now: " & User.YouCanChangeThisProperty")

This will give you a message box with: "User name: Some Name; the other property is now: Changed"

Upvotes: 1

matzone
matzone

Reputation: 5719

You can create New Class named User

Public Class User
    Private mstrName As String
    Private mdBirth As Date

    Public Property Name() As String
        Get
            Return mstrName
        End Get
        Set(ByVal vName As String)
            mstrName = vName
        End Set
    End Property

    Public Property BirthDate() As Date
        Get
            Return mdBirth
        End Get
        Set(ByVal vBirth As Date)
            mdBirth = vBirth
        End Set
    End Property

    ReadOnly Property Age() As Integer
        Get
            Return Now.Year - mdBirth.Year
        End Get
    End Property
End Class

You can use this class like this :

Dim Name1 as New User
Name1.Name = "ADMIN"
Name1.BirthDate = CDate("February 12, 1969")

Then Check it (by Msgbox or whatever) :

Msgbox(Name1.Name)
Msgbox(Name1.BirthDate.ToString & " and Now is " & format(Name1.Age) & " years old")

Upvotes: 1

Fabian Bigler
Fabian Bigler

Reputation: 10895

I suggest you define a class for such 'global' properties. For example, you could name it 'ProjectSettings'.

Public Class ProjectSettings
    Public Shared CurrentUser as String
    Public Shared DateTimeFormat as String
    ...etc...
    Public Shared Sub Initialize()
    'Initialize your members here
    End Sub
End Class

From outside, you could access it like this:

ProjectSettings.CurrentUser
ProjectSettings.DateTimeFormat

But remember, there are heaps of different approaches of how to do this. In the above case, you could also define the Members as Readonly Properties, making sure nobody accidentally overwrites the values. Or you could define an object 'User' for CurrentUser, if you need to store more data.

It really depends on what you want to achieve with your global properties. It's only important to keep them central so that everybody in your team (including yourself) knows where to find them. Else it can easily lead to unstructured, bad code.

Upvotes: 2

Tom F
Tom F

Reputation: 817

You could create a class that encapsulates all of this data inside of it:

Example:

Public Class User

    Public Property Name As String
    Public Property Age As Integer

    Sub New(_Name As String, _age As Integer)
        Name = _Name
        Age = _age
    End Sub

End Class

Then, you'd just declare it, and set the properties:

Dim U as new User("Thomas", 18)
Messagebox.Show(U.Name) ' Will print "Thomas"

Upvotes: 2

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