Help me figure out the Dispose () implementation code from MSDN

Question

following code from MSDN: Identifiable Template

protected virtual void Dispose(bool disposing)
    {
        // If you need thread safety, use a lock around these 
        // operations, as well as in your methods that use the resource.
        if (!_disposed)
        {
            if (disposing) {
                if (_resource != null)
                    _resource.Dispose();
                    Console.WriteLine("Object disposed.");
            }

            // Indicate that the instance has been disposed.
            _resource = null;
            _disposed = true;   
        }
    }

why the following statement:

 _resource = null;  
_disposed = true; 

not enclosed in an if (disposing) block of an operator?

for me I would probably write like this:

if (disposing) {
       if (_resource != null) {
            _resource.Dispose();
            _resource = null;
            _disposed = true;
           }
         Console.WriteLine("Object disposed.");
   }

Is there something wrong with my version?

Answer 1

The template designated by MSDN is the only correct way to implement IDisposable, since it takes into account the final development. You need to carefully study the implementation of IDisposable:

public void Dispose() 
{
    Dispose(true);

    // Use SupressFinalize in case a subclass
    // of this type implements a finalizer.
    GC.SuppressFinalize(this);      
}

This calls your dispose method, indicating that it really destroys and undoes further refinement.

It is not possible to call any other object during finalization, so you want to set:

 _resource = null;  
_disposed = true; 

.

IDisposable MSDN.

Answer 2

Dispose() , . , _resource NULL, .

_resource = null;

, .

Answer 3

;)

, _resource = null - , , . , ;) .

_disposed = true, , , _resource. , _resource , Console.WriteLine. , _resource , - , , , dispose .

if (disposing) {
if (_resource != null) {
_resource.Dispose();
_resource = null;
}
_disposed = true;
Console.WriteLine("Object disposed.");
}


.

Answer 4

Dispose(bool) Dispose(), Finalizer ( ~ Class in #). , . _resource , Dispose(bool) Dispose(), " " ( , )

Answer 5

, , MSDN

, , , , Dispose (bool) false Finalizer. , Finalizer , . , Finalizer.

I wrote an improved version of the IDisposable template on my blog - How do you implement the IDisposable template correctly? . You will find that my intended implementation of this template is slightly different from what is published on MSDN. IMHO, this is not enough. You must agree that a large number of samples and examples posted on MSDN are “hacked” and do not do what they should do in the “real world”.