Topic: Expose Methods across Mangaged DLLs

[SomeCallMeDave]

Hi All,

I was wondering if there is a way to expose method(s) from one managed DLL loaded in acad to another managed DLL loaded in acad.  Similar to the way methods can be exposed from a managed DLL to LISP.

I would like to provide access without having to reference the other DLL at compile time.

Is this possible?

Thanks,
David

[troga]

Hi All,

I was wondering if there is a way to expose method(s) from one managed DLL loaded in acad to another managed DLL loaded in acad.  Similar to the way methods can be exposed from a managed DLL to LISP.

I would like to provide access without having to reference the other DLL at compile time.

Is this possible?

Thanks,
David

I think it could work with exposing the function from both dll´s to lisp and call the functions through->.NET ... sample:
    doc.SendStringToExecute( "theFunctionYouWantToCall", params.., .., );


a usefull link: http://through-the-interface.typepad.com/through_the_interface/2006/08/calling_command.html

I think that there is a far better way to do that, but if it works... who cares


cheers.

[Draftek]

If the client code is not too difficult, you could expose the server as com and use late binding.

[SomeCallMeDave]

Troga,
The functions that I want to expose aren't acad command-line commands, but more like a mini-api that users could call from their .net programs.  So I don't think sendSend or its cousins will work (unless I misunderstand their usage, which is very probable).

Draftek,
Do you have an example of how your idea would work?


Thanks both.

[Draftek]

Probably a bit more than you need but you get the idea:

        // method to insert a drawing file into autocad using late binding.
        // Tested for versions 2000 to 2010
        public static void InsertDrawingLB(string sDwgName)
        {
            object acadApp = null;
            object[] parameters;
            object cmd = null;
            if (!File.Exists(sDwgName))
            {
                throw new System.ArgumentException("Drawing does not exist", "sDwgName");
            }
            // try to open an existing instance
            try
            {
                acadApp = (object)Marshal.GetActiveObject("AutoCAD.Application");
            }
            catch // if not successful try to start a new instance
            {
                try
                {
                    StartUpAcadDialog frm = new StartUpAcadDialog();
                    frm.Show();
                    frm.Height = 67;
                    Application.DoEvents();
                    acadApp = (object)Microsoft.VisualBasic.Interaction.CreateObject(
                            "AutoCAD.Application", null);
                    parameters = new object[1];
                    parameters[0] = true;
                    cmd = acadApp.GetType().InvokeMember("Visible",
                        BindingFlags.SetProperty, null, acadApp, parameters);
                    frm.Close();
                }
                catch // you don't even have autocad installed
                {
                    throw new System.Exception("Could Not find AutoCAD to open"); 
                }
            }
            try // need to make autocad active and the top dog
            {
                cmd = acadApp.GetType().InvokeMember("Caption",
                    BindingFlags.GetProperty, null, acadApp, null);
                string caption = (string)cmd;
                Microsoft.VisualBasic.Interaction.AppActivate(caption);
                cmd = acadApp.GetType().InvokeMember("WindowState",
                    BindingFlags.GetProperty, null, acadApp, null);
                parameters = new object[1];
                parameters[0] = 3;
                cmd = acadApp.GetType().InvokeMember("WindowState",
                    BindingFlags.SetProperty, null, acadApp, parameters);
            }
            catch
            {
                throw new System.Exception("Problem forcing the AutoCAD window to Top");
            }
            object dwg = null;
            try // finally, insert the drawing using the newest technology - a script!!!
            {
                // first get the drawing
                try
                {
                    dwg = acadApp.GetType().InvokeMember("ActiveDocument",
                        BindingFlags.GetProperty, null, acadApp, null);
                }
                catch
                {
                    throw new System.Exception("You must have a drawing loaded");
                }
                string sTemp = "(Command " + @"""" + "Insert" + @"""" + " " + @"""" +
                        sDwgName + @"""" + " )" + "\r";
                parameters = new object[1];
                parameters[0] = sTemp;
                cmd = dwg.GetType().InvokeMember("SendCommand",
                    BindingFlags.InvokeMethod, null, dwg, parameters);
            }
            catch
            {
                throw new System.Exception("Could not Insert the drawing");
            }
        }

[SomeCallMeDave]

Probably a bit more than you need but you get the idea:

Thanks Draftek.  I will check it out

[Draftek]

Forgot to mention - I'm merely accessing autocad. You will need to expose your dll to com and register it before you can access it from the client.

[It's Alive!]

try using System.Reflection
http://msdn.microsoft.com/en-us/library/d8ba5k1h.aspx

[SomeCallMeDave]

Thanks Daniel.

That looks like what I probably need.

I have a couple more questions, but I need to do some reading and playing before I ask them.


Thanks again to everyone.

[It's Alive!]

Here is a  hack, if you know the function you want to call, its params and return type
( I haven't tried it with Acad)

this is a function inside a assembly call callee

Code: [Select]

public static class Callee
 {
  public static string Doit (int num)
  {
   return num.ToString();
  }
 }
and here is a method in another exe

Code: [Select]

private void buttonCall_Click(object sender, EventArgs e)
  {
   Assembly ass = Assembly.LoadFrom("..\\..\\..\\Callee\\Bin\\Debug\\Callee.dll");
   MethodInfo meth = ass.GetTypes()[0].GetMethod("Doit");

   if (meth.IsPublic && meth.IsStatic)
   {
    object res = meth.Invoke(null, new object[] { 123 });
    if (res != null)
    {
     if (res is String)
     {
      this.textBox1.Text = res.ToString();
     }
    }
   }
  }
 }

[SomeCallMeDave]

Woot!

That works for me inside Autocad with only a bit of tweaking.

Thanks Daniel.  I really appreciate the help.


Now, the next questions , if I may get greedy   

Is there a way to access the DLL that has been already loaded in-process with Autocad, something to the effect of Assembly.LoadFromAutocadProcess rather than Assembly.LoadFrom(filename)?  I would like to be able to do this so that I can share data that has been gathered from the Autocad user by one DLL with the other DLL without resorting to storing that data in the drawing (dictionary, xdata, etc).

[It's Alive!]

have a look at this code and see if it will work for what you need.

A lispfunction in a loaded dll

Code: [Select]

namespace Autodesk.AutoCAD.NetInvoke
{
 public class MyCommands
 {
  [LispFunction("MyLispFunction")]
  public ResultBuffer MyLispFunction(ResultBuffer args)
  {
   List<TypedValue> list = new List<TypedValue>(args.AsArray());
   list.Reverse();
   ResultBuffer rb = new ResultBuffer(list.ToArray());
   return rb;
  }
 }
}
and the caller in another loaded dll

Code: [Select]

namespace Autodesk.AutoCAD.NetInvoker
{
 public class MyCommands
 {

  [DllImport("acad.exe", CallingConvention = CallingConvention.Cdecl)]
  extern static int acedInvoke(IntPtr rbIn, out IntPtr rbOut);

  public static ResultBuffer Invoke(ResultBuffer rbIn)
  {
   IntPtr pRb = IntPtr.Zero;
   acedInvoke(rbIn.UnmanagedObject, out pRb);
   return DisposableWrapper.Create(typeof(ResultBuffer), pRb, true) as ResultBuffer;
  }

  [CommandMethod("doit")]
  public void MyCommand()
  {
   ResultBuffer rbOut = new ResultBuffer();
   rbOut.Add(new TypedValue((int)LispDataType.Text, "MyLispFunction"));
   rbOut.Add(new TypedValue((int)LispDataType.Int32, 1));
   rbOut.Add(new TypedValue((int)LispDataType.Int32, 2));
   rbOut.Add(new TypedValue((int)LispDataType.Int32, 3));

   ResultBuffer rbIn = Invoke(rbOut);

   List<TypedValue> list = new List<TypedValue>(rbIn.AsArray());

   list.ForEach( X =>
    ApplicationServices.Application.DocumentManager.
    MdiActiveDocument.Editor.WriteMessage(X.Value.ToString()));
  }
 }
}
edit: added solution

[SomeCallMeDave]

Daniel,
Thanks again. 

That looks like what I needed.  After more coffee, lots of studying your code and some play time I will let you know.