用户定义类型和将数组传递给函数

Question

I'm having troubles passing an Array from user-defined Type to a Function:

Defined Type (in a standard Module):

Public Type JPrinters
    Available() As String
    Default As String
End Type

Function to make a list of all available printers (std Module):

Function ListPrinters() As JPrinters

    Dim GetPrinters As Object: Set GetPrinters = CreateObject("WScript.Network").EnumPrinterConnections     
    Dim i As Integer
    Dim j() As String  'Array of Printer Names
    ReDim j(0 To GetPrinters.Count \ 2 - 1)

    For i = 0 To UBound(j)
        'Load this array element with the Name from the list
        j(i) = GetPrinters.Item(i * 2 + 1)
    Next i

    Dim k As JPrinters
    With k
        .Available = j
        .Default = Application.ActivePrinter
    End With

    ListPrinters = k
End Function

Sub to populate a ComboBox by an Array (which works fine, normally – std Module):

Sub PopulateComboBoxBy2DArray(Ctrl As Control, ByVal Source_1D_2D_Array As String, Optional DefaultValue As String)
    Ctrl.List = Source_1D_2D_Array
    If DefaultValue Then
        Ctrl.Value = DefaultValue
    End If
End Sub

Then I try to call everything on Workbook_Open:

Private Sub Workbook_Open()
    Dim Prt As JPrinters
    Prt = ListPrinters
    PopulateComboBoxBy2DArray List1.PrinterList, Prt.Available, Prt.Default
End Sub

• All modules have Option Explicit defined.

And it just gives my Compile error: Type mismatch . I tried a lot but cannot figure out why it won't accept the Prt.Available Array. Any ideas?

(I will also be glad for any other suggestions regarding the code.)

Thank you,

J

Answer 1

Resolved (thanks to Dave from Mr. Excel forums). It goes like this:

Type:

Type J_Type_Printers
    Available() As Variant
    Default As Variant
End Type

Function:

Function J_Fx_ListPrinters() As J_Type_Printers
    Dim GetPrinters As Object
    Dim i As Integer
    Dim j() As Variant 'Array of Printer Names
    Dim k As J_Type_Printers

    Set GetPrinters = CreateObject("WScript.Network").EnumPrinterConnections
    ReDim j(0 To GetPrinters.Count \ 2 - 1)

    For i = 0 To UBound(j)
        'Load this array element with the Name from the list
        j(i) = GetPrinters.Item(i * 2 + 1)
    Next i

    With k
        .Available = j
        .Default = Application.ActivePrinter
    End With
    J_Fx_ListPrinters = k
End Function

Sub to populate combobox by array contents:

Sub J_Sub_Controls_ComboBox_ListArray(ByVal Ctrl As ComboBox, ByVal SrcArray As Variant, Optional DefaultValue As Variant)
    Ctrl.List = SrcArray
    If Not IsMissing(DefaultValue) Then Ctrl.Value = DefaultValue
End Sub

Call on Workbook_Open:

Private Sub Workbook_Open()
    Dim Prt As J_Type_Printers: Prt = J_Fx_ListPrinters
    J_Sub_Controls_ComboBox_ListArray List1.PrinterList, Prt.Available, Prt.Default
End Sub

Answer 2

I believe the problem is the declaration of the Source_1D_2D_Array parameter. It is declared as string and it needs to be a string array. The type mismatch is because you are passing an string array to a string parameter.

Also the check for the DefaultValue needs to be a comparison. I think you want:

Sub PopulateComboBoxBy2DArray(Ctrl As Control, ByRef Source_1D_2D_Array() As String, Optional DefaultValue As String = "")
    Ctrl.List = Source_1D_2D_Array
    If DefaultValue<>"" Then
        Ctrl.Value = DefaultValue
    End If
End Sub