Global Variable Access Problem c#

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hi friends..

I am working on a project in c#, and I declared all constant, error msgs etc in a dll.(using classlibrary).
Now I want to access all of them into my project.For that I declared the namespace and then I created an object of the class, but I am not able to access the variables.

What can I do as I don't have any idea? Is there any other way to access these variables.

Thanks
Swapnil

[Edit] Removed TextSpeak and improved grammar[/Edit]

Posted 14-Mar-12 1:32am

swapnilKumbhar

Updated 14-Mar-12 1:42am

Wayne Gaylard

v2

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Comments

johannesnestler 14-Mar-12 10:49am

Are you shure you know what the "const" keyword is for in c#? you won't get instance variables this way. Caution if you come from c++! (like I did..)

3 solutions

Solution 2

Maybe a soltion would be using static variables (maybe even in a static class),
or use "readonly" keyword. Compare this:

C#

MyConstants mc = new MyConstants();
    string strDefaultInstance = mc.strDEFAULT_INSTANCE;
    string strDefault = MyConstants.strDEFAULT;


public class MyConstants
{
    public const string strDEFAULT = "Default";
    public readonly string strDEFAULT_INSTANCE = "Default";
}

Posted 14-Mar-12 4:58am

johannesnestler

Comments

Sergey Alexandrovich Kryukov 15-Mar-12 0:22am

Such class should also be done static. For that purpose, also make strDEFAULT_INSTANCE static.
All instance objects here do not make sense.
--SA

johannesnestler 15-Mar-12 4:28am

Yes you are right (I mentioned that I'd use static variables in a static class), maybe the example is not the best, just wanted to point OP to the possibillity to create kind of "instance constants" - but I agree this doesn't make much sense - Thank you for pointing that out.

Sergey Alexandrovich Kryukov 15-Mar-12 21:44pm

Thank you.
After your words I decided to add my own answer with a link showing how to implement it correctly -- please see.
--SA

Solution 3

There is no a notion of global variable in .NET (thank goodness! finally!).

You may need to know how the singleton pattern works:
http://en.wikipedia.org/wiki/Singleton_pattern[^].

Good .NET implementation of it is explained here:
http://csharpindepth.com/Articles/General/Singleton.aspx[^].

—SA

Posted 15-Mar-12 15:43pm

Sergey Alexandrovich Kryukov

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Wayne Gaylard · Accepted Answer · 2012-03-14T01:37:00

Solution 1

Have you referenced the dll in Solution Explorer - Add Reference ? If so, have you declared the variables public in the dll ?

Posted 14-Mar-12 1:37am

Wayne Gaylard

Comments

swapnilKumbhar 14-Mar-12 7:40am

Yes i did..
I hv also create Object of that Class.And all variables are in public.
But am not able access them.

Wayne Gaylard 14-Mar-12 7:45am

Are the variables static or are they non-static ? If they are static you cannot access them using an instance of the class, you need to just preface the variable with the class name i.e YourClass.YourVariable as a pose to classObj.YourVariable.

swapnilKumbhar 14-Mar-12 7:54am

All are non static
namespace BatchCard
{
class BCC
{
#region BLANK String
Public Const string IssDates="";
#endregion
}
}

Then
In my Project, i add BatchCard dll from reference,
Then Created Obj of class i.e.
BCC b1=new BCC();

Now i want to access tht variable. i.e. b1.IssDates
obj didnt show reference to variable.

Wayne Gaylard 14-Mar-12 8:13am

I tried a test and it would only let me access that const with a type name and not an instance of the class.
dll:-
public class Class1
{
public const string IsDate = "";
}
usage:
public Form1()
{
Class1 class1 = new Class1();
string isDate = class1.IsDate;//Throws error - need to use type name not instance
string isDate = Class1.IsDate;//No error
}

Hope this helps

johannesnestler 14-Mar-12 10:53am

const variable static or not static? http://msdn.microsoft.com/en-us/library/e6w8fe1b(v=vs.71).aspx - you won't get "instance" variables with const...

Wayne Gaylard 14-Mar-12 10:59am

That's what I was trying to tell the OP, by my demo.

johannesnestler 14-Mar-12 11:09am

ah, ok sorry I didn't get it ;-)

Sergey Alexandrovich Kryukov 15-Mar-12 0:19am

Exactly. All const declarations are static!
--SA

swapnilKumbhar 14-Mar-12 12:38pm

thnks a lot
it really helps..

Sergey Alexandrovich Kryukov 15-Mar-12 0:20am

IssDates is static, don't worry.
Don't use "", use string.Empty.
--SA

Sergey Alexandrovich Kryukov 15-Mar-12 0:21am

Itemized. A 5.
--SA