C# generic static field problem

Question

0.00/5 (No votes)

See more:

C#

public class base{ public string f1; }

public class Derive1{  }

public class Derive2{  }

void fun1<T>() where T: base
{
   T t = new T();
   string f = t.f1;
}

above code works well.
let change the f1 to a static field.

What I have tried:

C#

public class base{ public static string f1; }

public class Derive1{  }

public class Derive2{  }

void fun1<T>() where T: base
{   
   string f = T.f1;  // complie error
}

How to make this code works with the static field?

Posted 12-Sep-18 5:58am

855

Updated 12-Sep-18 9:53am

Patrice T

v3

Add a Solution

2 solutions

Solution 1

You can't, not without reflection - generics do not support anything static. This shows how to use reflection to do it, if you really must. Slow though: C# accessing a static property of type T in a generic class - Stack Overflow[^]

Posted 12-Sep-18 6:28am

OriginalGriff

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

raddevus · Accepted Answer · 2018-09-12T09:53:00

Why doesn't this code (my altered example below) work? I just tried it in Linqpad (LINQPad - The .NET Programmer's Playground[^]);

C#

void Main()
{
	main m = new main();
	main.f1 = "super";
	fun1<main>();

        Derive1 d = new Derive1();
	fun1<Derive1>();
}
public class main{ static  public string f1; }

public class Derive1: main{  }

public class Derive2 : main{  }

void fun1<T>() where T: main
{   
   string f = main.f1;  // NO compile error
   Console.WriteLine(f);
}

The output will be :

super
super

which is the value of the static variable. You cannot access the static the way you were doing it. It is a CLASS variable not an instance variable. Your way was accessing the instance var.

Edit
Altered code and added Derive1 instance and ran method with that class and it works too.
Now it outputs the value (super) twice.