问题
How can I make Visual Studio to use the 64bit compiler (csc.exe/vbc.exe) for an Asp.Net web site?
回答1:
Apparently you can't. x86 compilation will occur with VS 2008 and x64/x86 compilation will occur with your IIS (depending on your window's platform). You can't change it even by using the compilation parameters at the web.config - an error will occur.
来源：https://stackoverflow.com/questions/2641844/how-to-compile-64bit-asp-net-web-site-with-visual-studio