使用IDisposable接口的原因

Question

我们都知道IDisposable接口用于处理非托管资源.我有一个包含以下代码的类.这里我已经从IDisposable接口实现了Dispose方法.

  class ClassA:IDisposable
    {
    public ClassA()
    {
    Console.WriteLine("ClassBeingTested: Constructor");
    }
    private bool disposed = false;
    Image img = null; 

    public Image Image
    {
    get { return img; }
    } 

    ~ClassA()
    {
    Console.WriteLine("ClassBeingTested: Destructor");
    // call Dispose with false. Since we're in the
    // destructor call, the managed resources will be
    // disposed of anyways.
    Dispose(false); 
    }

    public void Dispose()
    {
    Console.WriteLine("ClassBeingTested: Dispose");
    // dispose of the managed and unmanaged resources
    Dispose(true);

    // tell the GC that the Finalize process no longer needs
    // to be run for this object.
    GC.SuppressFinalize(this);
    }

    protected virtual void Dispose(bool disposeManagedResources)
    {
    // process only if mananged and unmanaged resources have
    // not been disposed of.
    if (!this.disposed)
    {
    Console.WriteLine("ClassBeingTested: Resources not disposed");
    if (disposeManagedResources)
    {
    Console.WriteLine("ClassBeingTested: Disposing managed resources");
    // dispose managed resources
    if (img != null)
    {
    img.Dispose();
    img = null;
    }
    }
    // dispose unmanaged resources
    Console.WriteLine("ClassBeingTested: Disposing unmanaged resouces");
    disposed = true;
    }
    else
    {
    Console.WriteLine("ClassBeingTested: Resources already disposed");
    }
    }
    // loading an image
    public void LoadImage(string file)
    {
    Console.WriteLine("ClassBeingTested: LoadImage");
    img = Image.FromFile(file);
    }

    }

我怀疑为什么我需要从IDisposable接口实现Dispose方法？而不是我可以在我的类中创建自己的Dispose方法而不继承我下面给出的IDisposable接口.

对于下面的类,我没有从IDisposable接口继承我的类.而不是我创建了自己的dispose方法.这也行得很好.

    class ClassA
    {
    public ClassA()
    {
    Console.WriteLine("ClassBeingTested: Constructor");
    }
    private bool disposed = false;
    Image img = null;

    public Image Image
    {
    get { return img; }
    } 

    ~ClassA()
    {
    Console.WriteLine("ClassBeingTested: Destructor");
    // call Dispose with false. Since we're in the
    // destructor call, the managed resources will be
    // disposed of anyways.
    Dispose(false); 
    }

    public void Dispose()
    {
    Console.WriteLine("ClassBeingTested: Dispose");
    // dispose of the managed and unmanaged resources
    Dispose(true); 
    // tell the GC that the Finalize process no longer needs
    // to be run for this object.
    GC.SuppressFinalize(this);
    }

    protected virtual void Dispose(bool disposeManagedResources)
    {
    // process only if mananged and unmanaged resources have
    // not been disposed of.
    if (!this.disposed)
    {
    Console.WriteLine("ClassBeingTested: Resources not disposed");
    if (disposeManagedResources)
    {
    Console.WriteLine("ClassBeingTested: Disposing managed resources");
    // dispose managed resources
    if (img != null)
    {
    img.Dispose();
    img = null;
    }
    }
    // dispose unmanaged resources
    Console.WriteLine("ClassBeingTested: Disposing unmanaged resouces");
    disposed = true;
    }
    else
    {
    Console.WriteLine("ClassBeingTested: Resources already disposed");
    }
    }
    // loading an image
    public void LoadImage(string file)
    {
    Console.WriteLine("ClassBeingTested: LoadImage");
    img = Image.FromFile(file);
    }
    }

那么任何人都可以解释从IDisposable接口实现dispose方法背后的原因.

Answer 1

实施时IDisposable,可以使用using异常安全处置.