After passing variable to async method, how will setting variable to new instance in main thread affect async method?

Question

For instance:

void SomeMethod()
{
    MyObject o = new MyObject();
    // Do stuff with o
    SomeAsyncMethod(o);
    o = new MyObject(); // Will this affect what was passed to SomeAsyncMethod?
}

Anything I do to 'o' will be obviously be apparent in both the main and the new thread. However, if I set o equal to a new instance in the main thread it shouldn't change the fact the the variable in SomeAsyncMethod() is still pointing to the original instance of the object right?

Answer 1

No, it will have no effect on other o. however

void SomeMethod()
{
    MyObject o = new MyObject();
    // Do stuff with o
    SomeAsyncMethod(o);
    o.Id = 2222; // will change objects Id property, which will 
                 // be reflected in another thread
}

the reason is in your code you are changing value (reference) of local variable o, not the object itself