Linq and DataSetExtensions warnings using .NET Framework 2.0 and C# 3

I am receiving the following warnings:

Warning 1 Could not resolve assembly System.Xml.Linq. The target framework required by this assembly (3.5) is higher than the project target framework. If this reference is required by your code, you may get compilation errors. ConsoleAp开发者_如何学JAVAplication1

Warning 2 Could not resolve assembly System.Data.DataSetExtensions. The target framework required by this assembly (3.5) is higher than the project target framework. If this reference is required by your code, you may get compilation errors. ConsoleApplication1

Warning 3 The referenced component 'System.Xml.Linq' could not be found.

Warning 4 The referenced component 'System.Data.DataSetExtensions' could not be found.

Do you know how to fix them? My project needs to target .NET2.0, but I am allowed to use C# 3 features if they are supported.

System.Data.DataSetExtensions.dll is part of .NET 3.5; it might work simply by bundling the dll, but that isn't the supported route. The "fix" here is to either target .NET 3.5 and have .NET 3.5 as a pre-requisite; or don't use DataSetExtensions (use regular access instead; perhpas with some LINQBridge and just write the missing extension methods you want yourself).

If you aren't using DataSetExtensions in your code, then just remove the unnecessary references to System.Data.DataSetExtensions and System.Xml.Linq (in solution explorer).

If you are using Visual Studio 2008, target the project to use .NET 3.5. If you are using Visual Studio 2005, you'll need to upgrade to 2008 to use LINQ.