IDisposable

Context: IDisposable is an interface that provides a mechanism for releasing unmanaged resources (file handles, database connections, sockets) in a deterministic manner. The .NET GC only cleans up managed memory; unmanaged resources must be explicitly released. IDisposable defines a single method Dispose(). When you implement IDisposable, you should also implement a finalizer (destructor) as a safety net.

Usage Example

using System;
using System.IO;

public class ResourceHolder : IDisposable
{
    private FileStream _fileStream;
    private bool _disposed = false;

    public ResourceHolder(string path)
    {
        _fileStream = File.OpenRead(path);
    }

    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    protected virtual void Dispose(bool disposing)
    {
        if (!_disposed)
        {
            if (disposing)
            {
                _fileStream?.Dispose();
            }
            _disposed = true;
        }
    }

    ~ResourceHolder()
    {
        Dispose(false);
    }
}

Output console

// No direct output; the Dispose method is called automatically at the end of a using block.

Important notes

• Always call Dispose() when you are done with an IDisposable object.
• Use the using statement to guarantee disposal even if exceptions occur.

Real‑world usage example

File I/O – Every StreamReader, FileStream, or SqlConnection implements IDisposable. Always dispose them to free operating system handles.
See .NET docs on IDisposable.

Related sections

• 10.2.1 Unmanaged resources
• 10.2.2 Dispose pattern
• 10.2.3 using statement