Get in .NET string from C++ dll

Question

.NET

SW. specialists need help, two weeks are thrown out of life, so

there is a dll written in C ++ with very simple content. Question, how to call this function in .NET and get the result of its work? The question is not as simple as it seems, if you do return("bla bla bla") in C ++, then everything works fine, as soon as stdout appears, then nightmares begin. As a result of digging the network through Google, I found almost what I needed , they work as it should, but !!! works once, when you call it again, it will hang ... Thank you in advance for your help.

void IsolatedFunction()
{

cout << "Redirected string1" << endl << "Redirected string2" << endl;

}

Answer 1

Try not to create an instance of AnonymousPipeServerStream several times, but create it once and call SetStdHandle once, then calling server.Flush();, then the function from the dll and reading from the pipe. In general, something like this (I did not check the performance):

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1. public static class ConsoleOutRedirector
2. {
3.     #region Constants
4.  
5.     private const Int32 STD_OUTPUT_HANDLE = -11;
6.  
7.     #endregion
8.  
9.     #region Externals
10.  
11.     [DllImport("Kernel32.dll")]
12.     extern static Boolean SetStdHandle(Int32 nStdHandle, SafeHandleZeroOrMinusOneIsInvalid handle);
13.     [DllImport("Kernel32.dll")]
14.     extern static SafeFileHandle GetStdHandle(Int32 nStdHandle);
15.  
16.     #endregion
17.  
18.     #region Variables
19.  
20.     private static AnonymousPipeServerStream server = new AnonymousPipeServerStream(PipeDirection.Out);
21.     private static client = new AnonymousPipeClientStream(PipeDirection.In, server.ClientSafePipeHandle);
22.     private static bool First = true;
23.  
24.     #endregion
25.  
26.     #region Methods
27.  
28.     public static String GetOutput(Action action)
29.     {
30.         Debug.Assert(action != null);
31.  
32.         using (server)
33.         {
34.             if (First)
35.             {
36.                 var defaultHandle = GetStdHandle(STD_OUTPUT_HANDLE);
37.  
38.                 Debug.Assert(!defaultHandle.IsInvalid);
39.                 Debug.Assert(SetStdHandle(STD_OUTPUT_HANDLE, server.SafePipeHandle));
40.                 try
41.                 {
42.                     action();
43.                 }
44.                 finally
45.                 {
46.                     Debug.Assert(SetStdHandle(STD_OUTPUT_HANDLE, defaultHandle));
47.                 }
48.  
49.                 First = false;
50.             }
51.  
52.             server.Flush();
53.             client.Flush();
54.  
55.             using (client)
56.             {
57.                 using (var reader = new StreamReader(client))
58.                 {
59.                     using (var writer = new StringWriter())
60.                     {
61.                         while (reader.Peek() != -1)
62.                         {
63.                             writer.Write(Convert.ToChar(reader.Read()));
64.                         }
65.                         return writer.ToString();
66.                     }
67.                 }
68.             }
69.         }
70.     }
71.  
72.     #endregion
73. }
74.  

Answer 2

And if something like this ( source ), without problems with SetStdHandle and pipes? Unfortunately, I know C# pretty badly, so I can only advise at random =\