Hi,

   What data type(wchar or bstr or variant) I have to give for string in
atl com dll which will use in asp.net aplication and code-behind is visual c#?

code snippet:
STDMETHODIMP CMyTest::TestStringFunc(BSTR bstrFilesInfo)
{
    // TODO: Add your implementation code here
    return S_OK;
}

  In Visual C#, what data type I have to take to send the string data to
atl com dll?

   protected void Button1_Click(object sender, EventArgs e)
   {
       MyTestClass obj = new MyTestClass();
       obj.TestStringFunc("hi welcome to visual c#"); //application getting
crash here.
       Response.Write("Durga...4");
   }
//error info:Attempted to read or write protected memory. This is often an
indication that other memory is corrupt.

  Thanks in advance.