How to share constant values in .net namespaces?
I'm trying to port some code into .net which has a load of #define'd values e.g.
#define MY_CONSTANT (512)
#define MY_VERSION_STRING "v42.2"
When I import a cli library the #define's are lost. Is there a way of defining constants in the scope of a namespace. I was thinking something like this:
namespace MyNamespace
{
const int MY_CONSTANT = 512;
const String^ MY_VERSION_STRING = "v42.2";
}
So in future I could refer to that as:
int myVar = MyNamespace::MY_CONSTANT;
String^ myVar = MyNamespace::MY开发者_如何学编程_VERSION_STRING;
[Edit] Some of the constants are strings so an enum won't solve the general case.
[Edit2] I'm using C++/CLI here and right now interoperability with other .net languages is not a priority. That said, if there's a more .net-like way of solving this (i.e. standard practice) I'd rather go with that.
You can define a static class holding public fields that work as constants, eg.
namespace MyNamespace
{
public class Constants
{
public static int MyConstant1 { get { return 512; } }
public static int MyConstant2 { get { return 1024; } }
}
}
Then you can use Constants.MyConstant1 in place of MY_CONSTANT.
Note, though, that having a 'general' constants class is a 'bad practice': the kosher way is to keep related constants in the class related to what they define, eg. if you have a FileParser class that uses a MaxBufferSize constant, you would define a static FileParser.MaxBufferSize constant.
If there are multiple related values, it's usually better to do this with enums. Otherwise, hang them off a class, like:
public static class ConstantStuff
{
public const int MyConstant = 512;
public const int SomethingElse = 42;
}
C# doesn't allow "naked" constants.
I believe that if you put them at namespace scope they may not be accessible to C# apps, if that's important to you - best to wrap them in a ref class.
You cannot declare constants inside namespaces. You need to define a container to put your consts into, like a class, struct or enum.
public static class MyConstants
{
public const float ConstantValue1 = 0;
}
and refer to them like this:
float value = MyConstants.ConstantValue1 ;
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