title: Pass unicode string from VB.net to C++ dll
body: <p>I have tried a lot of things but I cannot get this to work. I can pass and receive ordinary strings (char*) to C++, but I cannot receive Unicode strings (<code>w_char_t *</code>) in C++.</p>
  
  <p>Here are some bits of the code on c++ </p>
  
  <pre><code>__declspec(dllimport) int __stdcall readFile(const w_char_t *file_path)
  </code></pre>
  
  <p>on VB.net</p>
  
  <pre><code>Public Declare Function readFile Lib "MyDll.dll" Alias "_readFile@4" (ByVal file_path As String) As Integer
  </code></pre>
  
  <p>when I change <code>w_char_t</code> to <code>char</code> I receive the correct string.</p>
  
  <p>I have found a lot of material on VB6, but not for VB.net</p>
  
  <p>Any help greatly appreciated.</p>
  
  <p>Leon</p>