Compatibility tests of. NET Framework versions

I wroteProgramAs a result, it cannot be deployed on Windows XP. Therefore, we tested the compatibility of the. NET program:

1... Net 4.5 cannot run on. NET 4. Even if you change 4.5 to 4.0 in xx.exe. config: <supportedruntime version = "v4.0" SKU = ". netframework, version = v4.5"/>, it still cannot run.

2. the. NET 2.0 program cannot be run on a machine where only. Net 4.0 is installed, but it can run on. NET 3.5. The root cause for running on. NET 3.5 Is that. Net 3.5 is installed with. NET 2.0, which can be seen in "Add/delete programs.

3. Features of a higher version, such as The async asynchronous keyword of 4.5, can be prompted During writing, but the system cannot change the color of this keyword, using system. threading. task. So you don't have to worry about the features of a higher version and whether it can be used in a lower version.