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How to Resolve Warning "CS0465: Introducing a 'Finalize' method can interfere with destructor invocation" in C#

The Compiler Warning CS0465 is a design warning related to Garbage Collection and Destructors. The message reads: "Introducing a 'Finalize' method can interfere with destructor invocation. Did you intend to declare a destructor?"

In the .NET Framework, the method signature Finalize() is reserved for the internal mechanism that cleans up unmanaged resources before an object is collected by the Garbage Collector (GC). In C#, you do not define this method directly. Instead, you use Destructor syntax (the tilde ~).

If you manually declare a method named Finalize, the compiler warns you that this method mimics the internal GC entry point but does not actually function as a destructor, potentially leading to confusion or incorrect resource management.

Understanding Finalize vs. Destructors​

Under the hood (in Intermediate Language or IL), C# compiles destructors into a method named Finalize.

  • C# Code: ~MyClass() { ... }
  • IL Code: protected override void Finalize() { ... }

Because the runtime expects Finalize to be a special method called by the GC, defining a standard method with that specific name creates ambiguity. It suggests you might have come from a language like Java (where finalize was common) or C++ and are trying to write cleanup logic incorrectly for C#.

Scenario: Accidental Naming Conflict​

This warning usually occurs when a developer creates a method to wrap up a process (like "finalize transaction" or "finalize document") and unluckily chooses the reserved name Finalize.

Example of error:

public class Transaction
{
    public void Process()
    {
        // ... logic ...
    }

    // ⛔️ Warning CS0465: Introducing a 'Finalize' method can interfere 
    // with destructor invocation.
    // The compiler thinks you might have meant '~Transaction()'.
    public void Finalize() 
    {
        System.Console.WriteLine("Transaction completed.");
    }
}

In 99% of cases, you do not intend to write a Garbage Collection hook. You simply chose a verb that describes "finishing" something. The fix is to choose a different name that describes what is being finalized.

Solution: rename the method to Complete, Finish, Close, or Dispose.

public class Transaction
{
    public void Process()
    {
        // ... logic ...
    }

    // ✅ Correct: Renamed to avoid conflict with GC internals.
    public void Complete() 
    {
        System.Console.WriteLine("Transaction completed.");
    }
}
note

If you are implementing the Dispose Pattern to release resources, the standard method name is Dispose() (from the IDisposable interface), not Finalize().

Solution 2: Use Destructor Syntax (If Cleanup is Needed)​

If your actual intention was to write code that runs when the object is garbage collected (e.g., to release an unmanaged file handle or C++ pointer), you must use the C# destructor syntax. Do not define a method named Finalize.

Solution: use the tilde ~ followed by the class name.

public class UnmanagedResourceWrapper
{
    // ✅ Correct: This is a true Destructor (Finalizer).
    // The compiler translates this to 'protected override void Finalize()'.
    ~UnmanagedResourceWrapper()
    {
        // Cleanup unmanaged resources here
        System.Console.WriteLine("Object is being collected.");
    }
}
warning

Avoid Destructors: In modern .NET development, writing destructors (finalizers) is rarely necessary and degrades performance. Always prefer implementing IDisposable and using the using statement. Only use a finalizer if you directly hold an unmanaged resource (like an IntPtr) and need a failsafe in case Dispose() is not called.

Conclusion​

CS0465 is a "reserved word" warning.

  1. Check the Intent: Are you trying to finish a business process, or clean up memory?
  2. For Business Logic: Rename the method to Complete(), Finish(), or Submit().
  3. For Memory Logic: Use the ~ClassName() syntax (but prefer IDisposable).

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