How the static class's static method will know the caller?

问题

Imagine I have a static class and a static method inside that. And it has to be accessed by 10 different classes. But how the static class will know who has called it :(

It was an interview question....please rephrase it properly and answer me, I am new :(

回答1:

I would try the following:

public class ParentClass
{
}

public class ChildClass :  ParentClass
{
}

public static class StaticClass
{
    public static void SomeMethod(ParentClass d)
    {
        var t = d.GetType();
    }
}

public class StaticChildren
{
    public void Children()
    {
        var p = new ChildClass();

        StaticClass.SomeMethod(p);

    }
}

Just passing an instance is the simplest you can do here.

回答2:

As C# does not have a proper metaobject system, the only way I know of is via reflection. The following idea should give the idea:

public static string GetCaller()
{
    var trace = new StackTrace(2);
    var frame = trace.GetFrame(0);
    var caller = frame.GetMethod();
    var callingClass = caller.DeclaringType.Name;
    var callingMethod = caller.Name;
    return String.Format("Called by {0}.{1}", callingClass, callingMethod);
}

回答3:

You could use the stracktace to find out who called the static method!

class Foo
{
  public void static staticMethod()
  {
    // here i want to know who called me!
    StackTrace st = new StackTrace();
    ...
  }
}

class Bar
{
  public void Bar()
  {
    Foo.staticMethod();
  }
}