IDisposable Interface

Namespace: System

Represents a class that frees, releases, or resets unmanaged resources.

Declaration

public interface IDisposable
{
    void Dispose();
}
            

Remarks

The IDisposable interface is used to manage resources such as file handles, database connections, or graphics objects that are not managed by the .NET Common Language Runtime (CLR). When you have an object that implements IDisposable, you should call the Dispose method when you are finished with the object to release any unmanaged resources it holds.

The Dispose method should implement the logic to release unmanaged resources. It is also common practice to implement the Dispose pattern, which allows for safe disposal of objects even if exceptions occur.

It is strongly recommended to use the using statement in C# or the Using statement in Visual Basic when working with objects that implement IDisposable. The using statement guarantees that the Dispose method is called, even if an exception is thrown.

Members

Example

using System;
using System.IO;

public class MyFileHandler : IDisposable
{
    private StreamWriter _writer;
    private bool _disposed = false;

    public MyFileHandler(string filePath)
    {
        _writer = new StreamWriter(filePath);
    }

    public void WriteLine(string line)
    {
        if (_disposed)
        {
            throw new ObjectDisposedException(this.GetType().FullName);
        }
        _writer.WriteLine(line);
    }

    protected virtual void Dispose(bool disposing)
    {
        if (!_disposed)
        {
            if (disposing)
            {
                // Dispose managed resources.
                _writer.Dispose();
            }

            // Free unmanaged resources here.

            _disposed = true;
        }
    }

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

    // Destructor (finalizer) for demonstration purposes.
    ~MyFileHandler()
    {
        // Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
        // and call the 'Dispose(bool)' method from 'Dispose()' method
        Dispose(disposing: false);
    }
}

public class Program
{
    public static void Main(string[] args)
    {
        try
        {
            // Using statement ensures Dispose is called even if exceptions occur
            using (var handler = new MyFileHandler("output.txt"))
            {
                handler.WriteLine("Hello, World!");
                handler.WriteLine("This is a test.");
                // The file will be closed and resources released when exiting the using block.
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine($"An error occurred: {ex.Message}");
        }
    }
}
            

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