Trying to launch a MATLAB plot program from a .NET C# windows application

Hi, I am trying to call a MATLAB .m file from a C# windows app. I was able to create a .NET assembly using the MATLAB compiler. I added a reference to the dll created by the compiler and had to change the visual studio application properties, platform target to x64 to get the C# app to build ok. I also added the MWArray dll as a reference, not sure if required. It looked like the compiler created 2 dlls, one with the Native keyword added. I included the other dll as well as the MWArray dll as references.

Anyhow I have something like using namespace; also have using Mathworks.NET; I have mlclass mymatlabclass=new new mlclass ();//mlclass is the class name of the matlab assembly. mymatlabclass.method(); the program should launch the MATLAB plot with the second line but just seems to hang running from the debugger in Visual Studio with no errors. I was able to instantiate the class ok.

[Kojiro Saito]

Could you share some sample codes for our investigating in detail?

[Paul]

Hi I ran into an issue just trying to create the Mat lab executable using the compiler. I was able to select the net assembly and files required for application to run. The package button is not enabled and I get the error application must have a target and entry point defined. I did not see an add main file option, possibly I am using the wrong compiler option? Thanks Paul.

[Paul]

Just some additional information, When I select the add exported function (maybe you select this to select the main file) I get the error only matlab functions with a single entry point are acceptable as exported functions. Guessing I need to modify the matlab .m file?

[Paul]

Got it to build the package, just added a function at the top of the file. I should be able to post some code soon, thanks!

[Paul]

Still missing something I have using Visual; using Mathworks.MATLAB.NET; I added Visual.dll and MwArray.dll as references to the .net project. Visual is the name of the namespace. I have a button on a windows form and in button select event I have Myclass callMat = new MyClass();//this causes an exception then I tried Myclass callMat = null; and callMat.NameofMethod(); but get null error when calling method, callMat is a null object. The compiler also created a dll called VisualNative.dll, was not sure if I needed to include it with the .net project. Thanks Paul.

Answer 1

[Paul]

Hi I should be able to provide some sample code within the next few days. Thanks Paul.

Answer 2

[Kojiro Saito]

Suppose you have compiled MATLAB function (call "NameofMethod") to .NET assembly (call Visual) and got Visual.dll. I think you need to enclose your codes with "try catch" because the class instantiation and method invocation would make their exceptions at run time.

using Visual;
using Mathworks.MATLAB.NET;

namespace YOURNAMESPACE
{
  class Program
  {
      static void Main(string[] args)
      {
          Myclass callMat = null;
          int numOfOutput = 0;
          try
          {
              callMat = new MyClass();
              callMat.NameofMethod(numOfOutput);
          }
          catch (Exception e)
          {
              Console.WriteLine(e);
              throw;
          }
      }
  }
}

You can see Sample C# in documentation.

About **native.dll, here is a document. It uses Native .NET API instead of MWArray API.

[Paul]

Hi thanks for the information. I tried it but when it hits callMat= new MyClass(); it jumps to the catch code with an exception error so never executes the callMat.MethodName(NumOfOutPut); It is almost like it can not find MyClass() which is called Visual. I did reference the Visual.dll created with the Mat Lab compiler and do have using Visual; Any other ideas?

[Paul]

Hi, just I was able to get it to make it past callMat=new MyClass(); but it hangs now on the method call.

[Paul]

I was able to get it to instantiate the class by going to build->configuration manager and changing the setting any CPU to x64.

[Kojiro Saito]

That is a good news. Yes, we need to change platform target from any to x64 as the step 4 of this document describes. It's because MATLAB (& MATLAB Runtime ) supports only 64 bit.

[Paul]

Ok thanks for the additional information. Any idea why the Mat plot does not launch and the Visual Studio project just hangs up on the method call? I am not sure if there is any way to debug this, thanks Paul.

[Kojiro Saito]

I'm not sure good way of debugging other than Visual Studio debugger, but there's a document of calling compiled MATLAB plot from C#. Please see this document (in Simple Plot section). It might be helpful.

[Paul]

Ok, thanks I found a permissions error in the windows event viewer but can not tell if it is the issue.