Pass a string values from VC++ dll to C#.


Goals:

This project is a sample for sendind string value from VC++ dll to c#.

Steps:

1) copy the following code in vc++ dll project.

SAMPLE_API const char * OpenFile(const char *file)
{
std::string sample = "test";
char *Val = new char[sample.length() + 1];
strcpy(Val, sample.c_str());
return Val;
}

2) run the code and use this dll in C#

3) copy the following code in C#.

[DllImport("sample.dll", EntryPoint = "OpenFile")]
private static extern string OpenFile(string fileName);

private void Btn_Browse_Click(object sender, EventArgs e)
{
string Data = OpenFile(fileName);
MessageBox.Show(Data);
}