Using directive vs full path name

Question

Is there a general rule for referencing a type from a different namespace. Do you consistently use :

using System.Drawing;

instead of defining it when needed:

System.Drawing.Graphics gr;

I tend to type the full namespace when I'm only "calling" it once. Is there any best practice about that ?

Answer 1

What I use, (and what I believe most developers use), is to always say

using System.Drawing; 

and reserve

System.Drawing.Graphics gr;

only for places where there is a conflict with there being two Graphics defined in different namespaces, and, even then, I'll still rather use a using to differentiate them:

using MyGraphics=My.Own.Conflicting.Named.Graphics;
//  :
var myGraph = new MyGraphics();

Answer 2

Fully qualified names in code are distracting and noisy. I prefer to never have them. If there is a namespace conflict, a using alias can resolve that.

Besides, let's face it, 99.99% of us C# developers are using Visual Studio, so knowing what namespace and/or assembly a type is coming from is as quick as F12 or just hovering the mouse for a second.

The only time I like fully qualified names in code is in code samples, like here on Stack Overflow, to make it clear exactly what type is being used.