VBA只读打开绘图

Public Graphics As AcadApplication
 
Public Sub Loadtemplate(control As IRibbonControl)
    
    Dim strDrawing As String
    On Error Resume Next
    Set Graphics = GetObject(, "AutoCAD.Application")
    If Err.Description > vbNullString Then
        Err.Clear
        Set Graphics = CreateObject("AutoCAD.Application")
    End If
    strDrawing = "c:\temp\master.dwg"
    Graphics.Documents.Open (strDrawing)
    
    On Error GoTo 0
End Sub