64位进程中的64位dll Vista失败 - 无法加载DLL“dllname”：找不到指定的模块

I have a native C code, I compiled the code in vc++ 2008 and its compiled with 'x64' as platform in configuration manager and I have an c# application which is also compiled with 'x64' as platform and it calls the dll function. I have used Dllimport to call the function from the dll like below.I have a native C code, I compiled the code in