C# namespace alias - what's the point?

Question

Where or when would one would use namespace aliasing like

 using someOtherName =  System.Timers.Timer; 

It seems to me that it would just add more confusion to understanding the language.

Answer 1

That is a type alias, not a namespace alias; it is useful to disambiguate - for example, against:

using WinformTimer = System.Windows.Forms.Timer; using ThreadingTimer = System.Threading.Timer; 

(ps: thanks for the choice of Timer ;-p)

Otherwise, if you use both System.Windows.Forms.Timer and System.Timers.Timer in the same file you'd have to keep giving the full names (since Timer could be confusing).

It also plays a part with extern aliases for using types with the same fully-qualified type name from different assemblies - rare, but useful to be supported.

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Actually, I can see another use: when you want quick access to a type, but don't want to use a regular using because you can't import some conflicting extension methods... a bit convoluted, but... here's an example...

namespace RealCode {     //using Foo; // can't use this - it breaks DoSomething     using Handy = Foo.Handy;     using Bar;     static class Program {         static void Main() {             Handy h = new Handy(); // prove available             string test = "abc";                         test.DoSomething(); // prove available         }     } } namespace Foo {     static class TypeOne {         public static void DoSomething(this string value) { }     }     class Handy {} } namespace Bar {     static class TypeTwo {         public static void DoSomething(this string value) { }     } }