How to safely check .NET Framework version using a .NET Framework version that may not exist?

Question

I have an application built with .NET 3.5. If a user runs it without having .NET 3.5 installed, I want to have control of what they see and perhaps provide a message that they can understand (with a link to .NET 3.5) versus unhandled exception stack traces. But if they don't actually have .NET 3.5 how can my application control anything?

Answer 1

Are you assuming that at least SOME version of .NET is installed?

You could write a small loader to be compatible with all versions to do the check.

Or if .NET is not installed, found a simple batch program (though this could easily be done in C++ if you prefer).

@ECHO OFF
SET FileName=%windir%\Microsoft.NET\Framework\v1.1.4322
IF EXIST %FileName% GOTO Skip
ECHO.You currently do not have the Microsoft® .NET Framework 1.1 installed.
ECHO.This is required by the setup program for MyApplication.
ECHO.
ECHO.The Microsoft® .NET Framework 1.1 will now be installed on you system.
ECHO.After completion setup will continue to install MyApplication on your system.
ECHO.
Pause
SET FileName=
Start /WAIT .\dotnetfx.exe
Start .\Setup.exe
ECHO ON
Exit
Tongue Tiedkip
SET FileName=
Start .\Setup.exe
ECHO ON
Exit

This might also help.