title: Calling a custom type from a DLL written in C++ from c#
body: <p>I'm using a DLL written in c++ in my C# project. I have been able to call functions within the DLL using this code: </p>
  
  <pre><code>[DllImport("hidfuncs", EntryPoint = "vm_hid_scan", ExactSpelling = true, CharSet = CharSet.Ansi, CallingConvention = CallingConvention.Cdecl)]
          public static extern IntPtr VmHidScan();
  </code></pre>
  
  <p>Now I need to call a function that requres a custom type pointer. The Docs for the DLL layout the function like this:</p>
  
  <pre><code>hid_get_info(int n,PDEV_INFO *pdi)
  </code></pre>
  
  <p>I don't know how to use this custom pointer. Is this defined in the DLL? If so how can use it from C# project? If not do I need to include the header file in c#? Thanks in advance for your help. </p>