There is actually a (subtle) difference between the two. Imagine you have the following code in File1.cs:
// File1.cs
using System;
namespace Outer.Inner
{
class Foo
{
static void Bar()
{
double d = Math.PI;
}
}
}
Now imagine that someone adds another file (File2.cs) to the project that looks like this:
// File2.cs
namespace Outer
{
class Math
{
}
}
The compiler searches Outer
before looking at those using
directives outside the namespace, so it finds Outer.Math
instead of System.Math
. Unfortunately (or perhaps fortunately?), Outer.Math
has no PI
member, so File1 is now broken.
This changes if you put the using
inside your namespace declaration, as follows:
// File1b.cs
namespace Outer.Inner
{
using System;
class Foo
{
static void Bar()
{
double d = Math.PI;
}
}
}
Now the compiler searches System
before searching Outer
, finds System.Math
, and all is well.
Some would argue that Math
might be a bad name for a user-defined class, since there's already one in System
; the point here is just that there is a difference, and it affects the maintainability of your code.
It's also interesting to note what happens if Foo
is in namespace Outer
, rather than Outer.Inner
. In that case, adding Outer.Math
in File2 breaks File1 regardless of where the using
goes. This implies that the compiler searches the innermost enclosing namespace before it looks at any using
directive.
Bring up the Package Manager Console in Visual Studio - it's in Tools / NuGet Package Manager / Package Manager Console. Then run the Install-Package command:
Install-Package Common.Logging -Version 1.2.0
See the command reference for details.
Edit:
In order to list versions of a package you can use the Get-Package command with the remote argument and a filter:
Get-Package -ListAvailable -Filter Common.Logging -AllVersions
By pressing tab after the version option in the Install-Package
command, you get a list of the latest available versions.
Best Answer
Even though my Package Source was set to nuget.org in Package Manager Console, explicitly adding the
-Source nuget.org
argument fixed this for me.So an example of use would be:
Install-Package Akka.net -Source nuget.org
Akka.net being your package that you want to install, its just an example here.