L prefix for strings in C++

Question

I have a static library. This library have the following function defined

int WriteData(LPTSTR s)

The sample to call the function is

Answer 1

Try:

[DllImport("Test.dll")]
private static extern int TestFun([MarshalAs(UnmanagedType.LPTStr)] string s);

More information on marshaling with the MarshalAsAttribute on MSDN.