摘要： 最佳答案: Yes it is a problem. Much like you can't add a reference to a .NET 2.0 assembly from a .NET 1.0 or 1.1 project. The .NET 4.0 is a new runtime version of the framework (CLR). The .NET 3.5 and 3.0 releases both use the 2.0 runtime version of the framework (CLR).You can always add a reference 阅读全文