命名空间的怪异问题

Question

I'm trying to use the System.Drawing.Color namespace. I'm not able to define it at the top of the class:

However, I can reference it within the class. That is, I can use this line of code, and it works:

txtBox.BackColor = System.Drawing.Color.LightPink;

... but I'd rather just be able to do this:

txtBox.BackColor = Color.LightPink;

If it's a matter of a missing reference/dll, why am I able to make reference to System.Drawing.Color in my code?

Answer 1

Reasons I can think of why System.Drawing could be filtered in the usings dropdown:

1. it is already used ( -- nah, probably not, but anyway)
2. you're in a ASP.NET Service:

Caution: Classes within the System.Drawing namespace are not supported for use within a Windows or ASP.NET service. Attempting to use these classes from within one of these application types may produce unexpected problems, such as diminished service performance and run-time exceptions.

http://msdn.microsoft.com/en-us/library/system.drawing(v=VS.100).aspx

Answer 2

That's because it isn't a namespace. System.Drawing is the namespace, and Color is a structure ( struct ).

EDIT: Additionally, I'd advise to use a product such as ReSharper , which can correct stuff like this almost automagically. ReSharper rules!

Answer 3

System.Drawing.Color is a struct. Namespace is System.Drawing

Answer 4

您是否在项目References添加了对System.Drawing的References ？

Answer 5

You have to add it to your references - somehow it is missing.

then you have to declare using System.Drawing; in the top portion of your C# code then you can call Color.LightPink;