diff --git a/course/WinDriver/tools/tools/dllmain.cpp b/course/WinDriver/tools/tools/dllmain.cpp
index 6785c0ec9ddae7349cc3fb722185c838165011be..0ea299228605df6565b2ba0da7435edcefa9d547 100644
--- a/course/WinDriver/tools/tools/dllmain.cpp
+++ b/course/WinDriver/tools/tools/dllmain.cpp
@@ -1,6 +1,23 @@
 // dllmain.cpp : 定义 DLL 应用程序的入口点。
 #include "stdafx.h"
 
+extern "C"
+{
+    // CALLBACK
+    __declspec(dllexport) void Foo(HWND hWindow, HINSTANCE hInstance, LPSTR lpszCommandLine, int nCmdShow)
+    {
+        if (strlen(lpszCommandLine) != 0)
+        {
+            ::MessageBoxA(hWindow, lpszCommandLine, "我是标题", MB_OK);
+        }
+        else
+        {
+            ::MessageBoxA(hWindow, "lpszCommandLine is NULL", "我是标题", MB_OK);
+        }
+    }
+}
+
+
 BOOL APIENTRY DllMain( HMODULE hModule,
                        DWORD  ul_reason_for_call,
                        LPVOID lpReserved