General CS question about constants

I'm programming using C#, after programming on C. So I'm using a lot of constants such as "DEFAULT_USER_ID", "REMOTE_ADDRESS" and such..开发者_如何学Python.

It seems to me that it's pretty "old fashioned" to use such constants and maybe there is some other more elegant way for using some constant data between objects.

Any ideas on how this could be done elegantly?

Thanks.

Using constants for stuff like DEFAULT_USER_ID is still "the way to go" (unless you want it to be configurable, but that's another topic). --> const (C# Reference)

Don't use constants for enumerations (FILE_TYPE_DOC = 1, FILE_TYPE_XLS = 2, ...). This can be done more elegantly in C# with enums:

enum FileType {
   Doc,
   Xls,   // or, optionally, "Xls = 2".
   ...
};

You can also use this for flags (constants combinable by bitwise operators), which is another common use case of constants in C:

[Flags]
enum FontDecoration {
    None = 0,
    Bold = 1,
    Italic = 2,
    Underline = 4
}

1. Your naming convention doesn't fit .net. Use PascalCase instead of SCREAMING_CAPS
2. Be aware of the binary versioning semantics of constants in .net. You might want to use a static readonly field instead of const sometimes.
3. Where it's conceptually a good idea use enums instead of several integer constants.

You can use static or readonly properties, for instance, for App class

class MyClass {

public static readonly int myVal=10;

}

Another alternative is to store constant values in a .config file, that way you do not need to recompile your application to change your values if needed. Depending on how your code is being deployed, it may or may not be appropriate to have your settings exposed as plain text. See this article for a simple example of using a .config file: http://www.developer.com/net/net/article.php/3396111/Using-Application-Configuration-Files-in-NET.htm

Also you may define constants like that

    public static class Defaults
    {
        public const string MyName = "SuperName";
    }

    public  class MyClass
    {
        string s = Defaults.MyName;
    }

In such case you may use class Defaults anywhere in your app

Also you may want to know that there is two ways of defining constant variables in Static readonly vs const

How about config files? you guys don't use config files in C#? DEFAULT_USER_ID and REMOTE_ADDRESS look very much suited to be in a config file

You can always just use custom Enums so you get Visual Studio Intellisense.