NuGet for solutions with multiple projects

Suppose I have a solution with 3 projects:

• Core
• UI
• Tests

Some of the NuGet packages I use will apply to all 3 projects. Some will just apply to UI and Tests, and some will just apply to Tests (like NUnit).

What is the right way to set this up using NuGet?

1. Should I use "Add Library Package Reference" on all three projects any time I need a reference?
2. Should I use "Add Library Package Reference" the first time I need a package, and then use Add Reference->Browse for subsequent usages?

In either case, how many packages.config files should I have?

For anybody stumbling across this, now there is the following option :

> Right-click your solution > Manage NuGet Packages for Solution...

... Or:

> Tools > Library Package Manager > Manage NuGet Packages for Solution...

And if you go to the Installed packages area you can 'Manage' a single package across every project in the solution.

Use the console to target multiple projects

Tools > Library Package Manager > Package Manager Console

then use this command

Get-Project PROJECT-NAMES-WITH-COMMAS | Install-Package PACKAGENAME

for example

Get-Project Core,UI | Install-Package FluentDateTime

This sweet deal works for me:

PM> Get-Project -all | where {$_.Name -match "Songhay.Silverlight" -and
    $_.Name -notmatch "ApplicationLoader" -and $_.Name -notmatch ".Xml"}
    | ForEach-Object {Install-Package MvvmLight -project $_.Name}

If you want to install a package across multiple solutions I wrote a handy Powershell script for doing it, see here.

You can even filter the Get-Project -All command and target a sub-set of the project list.

You should use the "Add Library Package Reference" for all your external library on every project in your solution. You'll end up with a packages.config per project.

However, you'll download the package only one time and reuse them locally for all your other projects.

In Package Manager Console you can write the following command:

Get-Project -all | ForEach-Object {Get-Package -ProjectName $_.Name -filter 
PACKAGE_NAME} | where-object { $_.id -eq 'PACKAGE_NAME' } | Install-Package 
PACKAGE_NAME -Version VERSION

You can use that command for install or update as well (Update-Package)