Compiler Error CS0027

Keyword 'this' is not available in the current context

The this (C# Reference) keyword was found outside of a property, method, or constructor.

To fix this error, either modify the statement to eliminate use of the this keyword, and/or move part or all of the statement inside a property, method, or constructor.

The following example generates CS0027:

using System;
using System.Collections.Generic;
using System.Text;

namespace ConsoleApplication3
{
    class MyClass
    {

        int err1 = this.Fun() + 1;  // CS0027 

        public int Fun()
        {
            return 10;
        }

        public void Test()
        {
            // valid use of this
            int err = this.Fun() + 1;
            Console.WriteLine(err);
        }

        public static void Main()
        {
            MyClass c = new MyClass();
            c.Test();
        }
    }
}