Inner class and Outer class in c#

how to implement inner outer classes in c#

i have two nested classes

like

class Outer
{
    int TestVariable = 0;
    class Inner
    {
        int InnerTestVariable = TestVariable // Need to access the variable "TestVariable" here
    }
}

Its showing error while compiling.

It can be solved by

1) Makin开发者_开发百科g TestVariable as static

2) Passing an instance of Outer class to Inner class

but in java there is no need to create Instance or static .

can i use the same functionality in C# too ?

No, C# does not have the same semantics as Java in this case. You can either make TestVariable const, static, or pass an instance of Outer to the constructor of Inner as you already noted.

You can create an instance of inner class without even have outer class instance, what should happen in that case you think? That's why you can't use it

Outer.Inner iner = new Outer.Inner(); // what will be InnerTestVariable value in this case? There is no instance of Outer class, and TestVariable can exist only in instance of Outer

Here is one of the ways to do it

  class Outer
    {
        internal int TestVariable=0;
        internal class Inner
        {
            public Inner(int testVariable)
            {
                InnerTestVariable = testVariable;
            }
           int InnerTestVariable; //Need to access the variabe "TestVariable" here
        }
        internal Inner CreateInner()
        {
            return new Inner(TestVariable);
        }
    }

Make variable internal or pass to inner's constructor

Short answer: No,

You will somehow need to inject the TestVariable into your Inner class. Making your testVariable could potentially lead to undesired behaviour. My sugestion would be to inject it via the constructor.