C# Convert from .NET 3.5 to 3.0

2
votes

I had to downgrade my program from .NET 3.5 to 3.0. What I did was go properties->application and change the "Target Framework" from 3.5 to 3.0. is this the correct step? now I get warnings:

I only have this

using System;
using System.Collections.Generic;
using System.Collections;
using System.Text;
using System.IO;

but yet I get this

Warning 1 The primary reference "System.Core", which is a framework assembly, could not be resolved in the currently targeted framework. ".NETFramework,Version=v3.0". To resolve this problem, either remove the reference "System.Core" or retarget your application to a framework version which contains "System.Core". ProgName1

Warning 2 The primary reference "System.Xml.Linq" could not be resolved because it has an indirect dependency on the framework assembly "System.Core, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" which could not be resolved in the currently targeted framework. ".NETFramework,Version=v3.0". To resolve this problem, either remove the reference "System.Xml.Linq" or retarget your application to a framework version which contains "System.Core, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089". ProgName1

Warning 3 The primary reference "System.Data.DataSetExtensions" could not be resolved because it has an indirect dependency on the framework assembly "System.Core, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" which could not be resolved in the currently targeted framework. ".NETFramework,Version=v3.0". To resolve this problem, either remove the reference "System.Data.DataSetExtensions" or retarget your application to a framework version which contains "System.Core, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089". ProgName1

Warning 4 The primary reference "System.Xml.Linq", which is a framework assembly, could not be resolved in the currently targeted framework. ".NETFramework,Version=v3.0". To resolve this problem, either remove the reference "System.Xml.Linq" or retarget your application to a framework version which contains "System.Xml.Linq". ProgName1

Warning 5 The primary reference "System.Data.DataSetExtensions", which is a framework assembly, could not be resolved in the currently targeted framework. ".NETFramework,Version=v3.0". To resolve this problem, either remove the reference "System.Data.DataSetExtensions" or retarget your application to a framework version which contains "System.Data.DataSetExtensions". ProgName1

2
c#.netvisual-studio-2010
Sounds like you need to remove those references in your project and reload the appropriate references with Add Reference from the dialog box. – Tejs

2 Answers

5
votes

The warnings are telling you that those five assemblies are new to .Net 3.5 and cannot be referenced from .Net 3.0.
Just delete those references.

0
votes

It seems you are using Extension methods extensivly and this is one of the main reasons you're getting most of these errors.

You need 3.5 for extension methods.