VB6 Compile Error: User-defined type not defined

Question

I am working on an equation grapher in visual basic 6, but I am encountering an error upon running my program. I have narrowed down the error to the below block of code.

Option Explicit

Private Sub cmdGraph_Click()
Dim script_control As MSScriptControlCtl.ScriptControl
Dim x As Single
Dim y1 As Single
Dim y2 As Single

' Make a script control.
Set script_control = New MSScriptControl.ScriptControl
script_control.Language = "VBScript"

' Define the function.
script_control.AddCode _
    "Function TheFunction(X)" & vbCrLf & _
    "    TheFunction = " & txtExpression.Text & vbCrLf & _
    "End Function"

' Graph the equation.
y1 = script_control.Eval("TheFunction(" & xmin & ")")
For x = xmin + Dx To xmax Step Dx
    ' Evaluate the next value.
    y2 = script_control.Eval("TheFunction(" & x & ")")

    ' Draw the next line.
    picGraph.Line (x - Dx, y1)-(x, y2)

    ' Save the current Y value.
    y1 = y2
Next x

End Sub

I have checked the components:

Microsoft windows common controls 6.0
Microsoft windows common controls- 2 6.0
Microsoft script control 1.0

so I don't think the problem lies within components.

The code highlighted is:

New MSScriptControl.ScriptControl

on line no. 10 of the code block I provided. Any help on what the problem could be would be appreciated, thanks.

Edit: I Changed the 4th line of the code block to:

Dim script_control As MSScriptControl.ScriptControl

opposed to:

Dim script_control As MSScriptControl.ScriptControl

The highlighted text is now the 4th line of the code block.

Change "Dim script_control As MSScriptControlCtl.ScriptControl" in "Dim script_control As MSScriptControl.ScriptControl" and try again — bdn02
Didnt make a difference, but thanks for pointing that out. Edit: it did change the highlighted text to to the line "Dim script_control As MSScriptControl.ScriptControl". — JaskiratBoparai

MarkL MarkL · Accepted Answer · 2016-01-25T16:03:36

MSScriptControlCtl is a control (component).

MSScriptControl is a reference-able object.

To use MSScriptControl and instantiate it:

Set script_control = New MSScriptControl.ScriptControl

You need to select Microsoft Script Control through Project-References, not the Microsoft Script Control in components.

VB6 Compile Error: User-defined type not defined

1 Answers