How can I evaluate a string into an object in VBA?

Question

In my previous question, How do I assign a value to a property where the property name is supplied at runtime in VBA?, I learned to use CallByName to set a property in a cla

Answer 1

This time you're out of luck. There is no VBA equivalent of eval (not in Excel anyway...there is in Access VBA).

(Application.Evaluate() evaluates strings as Excel expressions, not as VBA code.)

Answer 2

Active Scripting Engine can help you. Instantiate ScriptControl ActiveX, use .AddObject() method to add reference to Excel's Application object to the script control's execution environment, set the third parameter to True to make all Application's members accessible too. Then just use .Eval() method to evaluate any property or method, which is the Application's member. The example below shows evaluation of Worksheets() property:

Sub TestQueryTable()
    Dim objQueryTable As QueryTable
    Dim strEvalContent As String
    strEvalContent = "Worksheets(""RAW DATA"").Range(""A1"").QueryTable"
    Set objQueryTable = EvalObject(strEvalContent)
    objQueryTable.Refresh
    MsgBox objQueryTable.Connection
End Sub

Function EvalObject(strEvalContent As String) As Object
    With CreateObject("ScriptControl")
        .Language = "VBScript"
        .AddObject "app", Application, True
        Set EvalObject = .Eval(strEvalContent)
    End With
End Function

If you are on 64-bit Office, this answer may help you to get ScriptControl to work.

Answer 3

There's the "Evaluate" method (or [ ] brackets). I don't think it will do exactly what you expect - as in run VBA code found in a string. You can look it up in the VBA help menu.