获取 AutoCAD.Application 实例

Question

我想获得一个 AutoCAD.Application 实例。 但是，在 AutoCAD 加载屏幕期间执行 GetActiveObject() 时会发生错误。 如果我设置断点并在加载完成后调用 GetActiveObject() ，则实例会正常运行。 加载窗口结束时，.Net 中是否有事件或其他方法可以使用？

static void Main(string[] args)
{
    AcadApplication objAcad = default(AcadApplication);
    const string strProgId = "AutoCAD.Application.24.1";

    Process myProcess = new Process();
    myProcess.StartInfo.FileName = @"C:\Program Files\Autodesk\AutoCAD 2022\" + "acad.exe";
    myProcess.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
    myProcess.Start();
    
    try
    {
        objAcad = Marshal.GetActiveObject(strProgId) as AcadApplication;
        if (objAcad is null)
            throw new Exception("obj is null");
    }
    catch(Exception ex) // An error occurs if no instance is running
    {
        Type acType = Type.GetTypeFromProgID(strProgId);

        objAcad = (AcadApplication)Activator.CreateInstance(acType, true);
    }

    objAcad.Visible = true;
}

Answer 1

通常这是这样完成的：

  AcadApplication acadApp = null;
  const string progId = "AutoCAD.Application.24.1";
 
  // Try to get a running instance of AutoCAD
  try
  {
      acadApp = (AcadApplication)Marshal.GetActiveObject(progId);
  }
  catch // An error occurs if no instance is running
  {
      try
      {
          // Try to create a new instance of AutoCAD
          acadApp = (AcadApplication)Activator.CreateInstance(Type.GetTypeFromProgID(progId), true);
      }
      catch
      {
          // If an instance of AutoCAD is not created then message and exit
          System.Windows.Forms.MessageBox.Show(
              "Instance of 'AutoCAD.Application' could not be created.");
 
          return;
      }
  }