An object reference is required for the non-static field or method or property

Question

I am trying Action<T,T> delegate and got the following error:

An object reference is required for the non-static field, method, or property

The event declaration looks as follows:

public event Action<string, string> FileStateProcess;

And the usage should looks like this:

if (FileStateProcess != null)
{
    FileStateProcess(file.FullName, temppath);
}

What am I doing wrong?

In what method is that code where you access `FileStateProcess`? — O. R. Mapper, Jul 07 '15 at 13:34
It seems that you are calling a non static event from a static method — Viva, Jul 07 '15 at 13:35
Probably you are calling a non-static property from a static method. — Microsoft DN, Jul 07 '15 at 13:35

score 3 · Accepted Answer · answered Jul 07 '15 at 14:01

From your declaration we can see that the FileStateProcess action is non-static, so I assume the method from which you are calling it is a static method. In which case, remove the static keyword from the method and you should be good.

Alternatively, you can make FileStateProcess static, but this will mean that its value will be held in the actual type, rather than in an object instance.

public static event Action<string, string> FileStateProcess;

For more info, see:

Static Classes and Static Class Members (C# Programming Guide).

An object reference is required for the non-static field or method or property

1 Answers1