Help me convert the following VB/C++ code to C#

Question

I have been trying to get the following VB code running in C# for hours now. I keep getting a Value does not fall within the expected range. exception on the CreateStroke() call. Also, here is the Microsoft documentation with a C++ version as well.

Option Explicit
Dim theInkCollector As InkCollector

Private Sub Form_Load()
    Set theInkCollector = New InkCollector
    theInkCollector.hWnd = Me.hWnd
    theInkCollector.Enabled = True

    //Create a set of three points, stored as x1, y1, x2, y2, x3, y3
    //in an array of six Long elements, starting at index 0.
    Dim ptStrokePoints(5) As Long
    ptStrokePoints(0) = 200
    ptStrokePoints(1) = 200
    ptStrokePoints(2) = 400
    ptStrokePoints(3) = 600
    ptStrokePoints(4) = 900
    ptStrokePoints(5) = 300

    //The description value is an unused placeholder.
    Dim theDescription As Variant 
    Dim theStroke As IInkStrokeDisp
  Set theStroke = theInkCollector.Ink.CreateStroke(ptStrokePoints, theDescription)
End Sub

Here is what I have:

MSINKAUTLib.InkCollector collector = new MSINKAUTLib.InkCollector();
collector.hWnd = (int)(this.Handle);
collector.Enabled = true;

long[] pts = new long[6];
pts[0] = 200;
pts[1] = 200;
pts[2] = 400;
pts[3] = 600;
pts[4] = 900;
pts[5] = 300;

collector.Ink.CreateStroke(pts, new object());

Answer 1

That looks like the following error from the docs:

E_INVALIDARG - Invalid VARIANT type (only VT_ARRAY | VT_I4 supported).

The C# long type is a 64-bit integer, so you are passing a VT_ARRAY | VT_I8 (not VT_I4).

Change your pts declaration to:

int[] pts = new int[6];

and you should be good to go. (int is the C# 32-bit integer type.)