问题
The MSDN documentation doesn't generally specify the assembly a namespace is in, so there's no easy way to add the necessary assembly reference.
NOTE: I am using MonoDevelop, so right-click, resolve is not an option.
回答1:
Take a look at this example: http://msdn.microsoft.com/en-us/library/dd321424(VS.100).aspx
Task(Of TResult) Class
Represents an asynchronous operation that can return a value.
Namespace: System.Threading.Tasks
Assembly: mscorlib (in mscorlib.dll)
Namespaces can cross multiple assemblies, so you need to look for the assembly a specific class is in.
来源：https://stackoverflow.com/questions/2754220/how-do-i-determine-what-assembly-a-namespace-is-in