topic Re: vb.net external open cad drawing in .NET Forum

vb.net external open cad drawing

Anonymous — Wed, 18 Apr 2012 22:50:11 GMT

First off, I have working code for opening a cad drawing from an external program. That is perfect.

What I'm at a loss for is how can I force a drawing that is NOT readonly to open as readonly from outside cad. I know it's possible within cad, but that doesn't help me.

Can anyone help me out here?

Re: vb.net external open cad drawing

norman.yuan — Thu, 19 Apr 2012 13:51:37 GMT

How does your external program open a drawing? Without seeing your perfectly working code, I assume it automates AutoCAD via COM API AcadDocuments.Open() method (that is the drawing is still opened in AUTOCAD!)

This method has 2 optional argument to specify if the drawing to be opened as READONLY, and specify a PASSWORD if the drawing is password-protected:

AcadDocuments.Open "C:\....\mydrawing.dwg", True

opens a drawing as read-only.

Re: vb.net external open cad drawing

Anonymous — Thu, 19 Apr 2012 15:11:13 GMT

Actually, no. I'm using this to open drawings in cad..

System.Diagnostics.Process.Start(dwgpath)

Sounds like i should be doing the other way.. Is there some place I can get a look at working examples?

Re: vb.net external open cad drawing

chiefbraincloud — Thu, 19 Apr 2012 17:06:17 GMT

I have not tried it , but without rewriting all of your existing code, I believe you could just set the ReadOnly Attribute on the file.

Re: vb.net external open cad drawing

Anonymous — Thu, 19 Apr 2012 17:10:59 GMT

Not really an option (mainly because I still want the file to be editable at other times).

Re: vb.net external open cad drawing

chiefbraincloud — Thu, 19 Apr 2012 17:42:05 GMT

So Toggle the Attribute before opening, and toggle it back after closing. I assumed that went without saying.

Re: vb.net external open cad drawing

chiefbraincloud — Tue, 24 Apr 2012 06:25:23 GMT

I didn't mean my last comment to be condescending, and I agree with Norman, that if you use the built-in COM mechanisms to open a drawing, there is a built-in way to open them read-only, but I just thought I would try to provide an alternative way, that did not require a significant change in your existing code.

I will admit, my suggestion requires that the users of your program have (probably a network based) permission to alter the read/write access to the file in question. At my company, that problem could come into question under certain circumstances, but not usually when dealing with drawings.

Re: vb.net external open cad drawing

Anonymous — Tue, 24 Apr 2012 15:15:53 GMT

It's alright, everyone should let there inner Tony T out a few times. 🙂

I had briefly thought of doing it that way, but wasn't able to find a way of doing it. I've since gone the COM route. Works great (after several google searches and code corrections).

Re: vb.net external open cad drawing

Hallex — Tue, 24 Apr 2012 18:34:10 GMT

Would be interesting to show a result of your code,

Regards,

Oleg

Re: vb.net external open cad drawing

Anonymous — Tue, 24 Apr 2012 18:41:14 GMT

Not much to it, but here you go. (though for some reason cad crashes if it's used to many times in one session... (5+ i've found))

Used with vanilla 2011

Public Sub Open_DWG ()
        Dim ACAD As Object
        Dim MyAcadPath As String = "dwgpath"
        Dim bReadOnly As Boolean = True

        On Error Resume Next
        ACAD = GetObject(, "autocad.Application")
        If Err.Number <> 0 Then
            Err.Clear()
            ACAD = CreateObject("autocad.Application")
            If Err.Number <> 0 Then
                MessageBox.Show("Failed to start", MessageBoxButtons.OK, MessageBoxIcon.Information)
                GoTo EndOpen
            End If
        End If
        'ACAD.Visible = True
        Err.Clear()
        Dim NewFile As Object = ACAD.Documents.Open(MyAcadPath, bReadOnly)
        If Err.Number <> 0 Then
            MessageBox.Show("Failed to open", MessageBoxButtons.OK, MessageBoxIcon.Information)
        End If
EndOpen:
        ACAD = Nothing
        NewFile = Nothing
    End Sub

Re: vb.net external open cad drawing

Hallex — Tue, 24 Apr 2012 18:56:51 GMT

Thanks so much,

Happy computing 🙂

~'J'~