在具有託管和非託管資源的類中

讓 finalization 忽略託管資源非常重要。終結器在另一個執行緒上執行 - 在終結器執行時，託管物件可能不再存在。實現受保護的 Dispose(bool) 方法是一種常見做法，可確保託管資源不會從終結器呼叫其 Dispose 方法。

public class ManagedAndUnmanagedObject : IDisposable
{
    private SqlConnection sqlConnection = new SqlConnection();
    private UnmanagedHandle unmanagedHandle = Win32.SomeUnmanagedResource();
    private bool disposed;

    public void Dispose()
    {
        Dispose(true); // client called dispose
        GC.SuppressFinalize(this); // tell the GC to not execute the Finalizer
    }

    protected virtual void Dispose(bool disposeManaged)
    {
        if (!disposed)
        {
            if (disposeManaged)
            {
                if (sqlConnection != null)
                {
                    sqlConnection.Dispose();
                }
            }

            unmanagedHandle.Release();

            disposed = true;
        }
    }

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