Question

I am new to VB.NET and WPF.

I am building a “Questionnaire” app. Users will be presented sequentially with different questions/tasks (windows). After they respond on each question/task and press a “submit” button a new window will open with a new question/task, and previous window will close. After each question, when the button is pressed, I need to store data to some global object. After all questions are answered the data of this object should be written out to the output file.

I figured out that Dictionary will be the best to store the results after each window.

I am not sure how, where to create this global Dictionary and how to access it. Should I use View Model? If yes, can you give an example? Or, should it be just a simple class with shared property? (something like this)

EDIT 2: I tried many different ways recommended online

GlobalModule:

Module GlobalModule
   Public Foo As String
End Module

GlobalVariables:

Public Class GlobalVariables
   Public Shared UserName As String = "Tim Johnson"
   Public Shared UserAge As Integer = 39
End Class

Global properties:

Public Class Globals

Public Shared Property One As String
    Get
        Return TryCast(Application.Current.Properties("One"), String)
    End Get
    Set(ByVal value As String)
        Application.Current.Properties("One") = value
    End Set
End Property

Public Shared Property Two As Integer
    Get
        Return Convert.ToInt32(Application.Current.Properties("Two"))
    End Get
    Set(ByVal value As Integer)
        Application.Current.Properties("Two") = value
    End Set
End Property

End Class

Here is where I save the data to global variables/properties in the first window. I need to store data in this subroutine before closing an old window and opening a new window. I use MessageBox just for testing.

Private Sub btnEnter_Click(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles btnEnter.Click

    Dim instructionWindow As InstructionsWindow

    instructionWindow = New InstructionsWindow()

    Application.Current.Properties("number") = textBoxValue.Text

    Globals.One = "2"
    Globals.Two = 3

    MessageBox.Show("GlobalVariables: UserName=" & GlobalVariables.UserName & " UserAge=" & GlobalVariables.UserAge)

    GlobalVariables.UserName = "Viktor"
    GlobalVariables.UserAge = 34

    GlobalModule.Foo = "Test Foo"


    'testing if it saved tha value
    'MessageBox.Show(Application.Current.Properties("number"))

    Application.Current.MainWindow.Close()

    instructionWindow.ShowDialog()

End Sub

Next subroutine is where I am trying to retrieve the value from global Properties/variables in the second window, but message boxes come out empty. There might also the case that I am assigning values in a wrong way, or not reading them in a right way (casting?) :

Private Sub FlowDocReader_Initialized(ByVal sender As Object, ByVal e As System.EventArgs) Handles FlowDocReader.Initialized

    ' Get a reference to the Application base class instance.
    Dim currentApplication As Application = Application.Current

    MessageBox.Show(currentApplication.Properties("number"))

    MessageBox.Show("One = " & Globals.One & " Two = " & Globals.Two)

    MessageBox.Show("GlobalVariables: UserName=" & GlobalVariables.UserName & " UserAge=" & GlobalVariables.UserAge)

    MessageBox.Show("GlobalModule.Foo = " & GlobalModule.Foo)

    Dim filename As String = My.Computer.FileSystem.CurrentDirectory & "\instructions.txt"

    Dim paragraph As Paragraph = New Paragraph()
    paragraph.Inlines.Add(System.IO.File.ReadAllText(filename))
    Dim document As FlowDocument = New FlowDocument(paragraph)
    FlowDocReader.Document = document

End Sub

Thanks.

Answer 1

You can make public Dictionary property for form and put your dictionry to this property or make constructor with Dictionary argument.