How do I change the .Net Framework from version 3.5 to version 4.0

Question

I have created a class library in .NET Framework 3.5. Now I want to change the .NET Framework Version to 4.0.

How can I do this?

Answer 1

In Visual Studio:

1. Right-click on your project
2. Select Properties
3. Select the Application tab
4. Change the Target Framework to the desired framework

If you are not seeing .NET Framework 4 as an option there, ensure you have it installed.

EDIT

I don't think this is what you're asking, but for completeness, one can also point an existing DLL to a later version of the .NET Framework without recompiling using Binding Redirects .

Answer 2

1. Right click on the project in the solution explorer and select Properties .

2. Make sure that the Application tab is selected.

3. In the Target framework dropdown select the desired framework, eg .NET Framework 4 .

Answer 3

Unfortunately this cannot be done once dll has been created. For this you need to have source of your class library.

• Select Properties from Right clicking on the project in the solution explorer.

• In Application Tab change Target Framework to Desired one .

Answer 4

FYI - there's a "Target Framework Migrator" extension tool for Visual Studio (2013, 2015) that will do all projects in your solution in one go.

I'm working on a solution at the moment with a 100+ projects in it and it's not practicable to do each project one at a time IMO.

Answer 5

In Visual Studio 2010 :

1. Right-click on your Project
2. Select Properties
3. Select the Compile tab
4. At the bottom, select Advanced Compile Options
5. Change the Target Framework to the desired framework