When is dispose called c

NET Framework's way to deal with the 'graceful' cleanup and releasing of resources. While this is certainly more info that you asked for, it provides background on how things work and why they work the way they do. Some people will argue that they shouldn't have to worry about managing memory and resources in.

NET, but that doesn't change the fact that it needs to be done - and I don't see that going away in the near future. Unfortunately, the examples above mistakenly imply that you need to implement a Finalizer as part of the standard Dispose pattern. However, you should not implement a Finalizer unless you are using UNmanaged code. Otherwise, there are negative performance implications. I have posted a template for implementing the Dispose pattern here: How do you properly implement the IDisposable pattern?

You can't do that. The memory management is simply not built to accomodate resources that are not memory specifically. The IDisposable pattern is intended for developers as a way of telling an object when they are done with it, instead of having the memory management trying to figure that out by using things like reference counting. You can use the Finalizer as a fallback for users who fail to dispose objects properly, but it doesn't work well as the primary method for cleaning up objects.

To work smoothly objects should be disposed properly, so that the more costly Finalizer doesn't ever need to be called. Manually calling Dispose will also work, but the advantage of the using statement is that the object will also be disposed when you leave the control block because an exception is thrown. You could add a finalizer that handles the resource disposing in case someone "forgets" to use the IDisposable interface:. See this question for additional information.

However, this is just compensating for people not using your class correctly : I suggest you add a big fat Debug. Fail call to the Finalizer, to warn the developer of their mistake. If you choose to implement the pattern, you'll see that GC. Collect will trigger disposal. You will have to call Dispose explicitly or by wrapping the object in a using statement. Using using is the same as calling Dispose inside a finally block. Dispose does not get called automatically. You need to use a using clause to wrap usage or call it manually.

And just to preempt another idea you might have: you cannot call dispose from the destructor I tried this some time ago in a project.

You're supposed to dispose of it yourself, either calling the Dispose method or using using. Remember, it's not a deconstructor! If you can't trust the users of your class to dispose of resources properly, they will probably mess up in other ways anyway. Stack Overflow for Teams — Collaborate and share knowledge with a private group.

Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Techopedia Explains Dispose The. Dispose method rules are as follows: Used for unmanaged resources requiring immediate release after use. If Dispose is not called, the Finalize method should be implemented. After calling the Dispose method, the GC. SuppressFinalize method must be called to avert the Finalize method and avoid unnecessary GC. Exceptions should be carefully handled if the Dispose method is invoked more than once.

If resources are disposed, any instance method may throw the ObjectDisposedException. An object with a previously called Dispose method may not be reused.

Dispose is recommended only for the management of native resource objects and Component Object Model COM objects exposed to the. NET Framework. This object is being use at many places in the application. So in this scenario Finalize can be appropriate location where unmanaged resource can be released.

It means, clean the memory acquired by the unmanaged resource as soon as object is inaccessible to application. Finalize is bit expensive to use. It doesn't clean the memory immediately. Other term GC knows which object has Finalize implemented. When the object is ready to claim memory, Garbage Collector call finalize method for that object and remove from the collection. In this process it just clean the memory that used by unmanaged resource.

Memory used by managed resource still in heap as inaccessible reference. That memory release, whenever Garbage Collector run next time. Due to finalize method GC will not clear entire memory associated with object in fist attempt.

Conclusion It is always recommended that, one should not implement the Finalize method until it is extremely necessary. First priority should always be to implement the Dispose method and clean unmanaged as soon as possible when processing finish with that.

View All. Nitya Sharma Updated date Nov 23, Garbage collector GC plays the main and important role in. The System. SafeHandle is an abstract base class. Derived classes provide specific instances for different kinds of handle. These derived classes validate what values for the System. IntPtr are considered invalid and how to actually free the handle. Most APIs in. NET libraries that create an unmanaged resource will wrap it in a SafeHandle and return that SafeHandle to you as needed, rather than handing back the raw pointer.

In situations where you interact with an unmanaged component and get an IntPtr for an unmanaged resource, you can create your own SafeHandle type to wrap it. As a result, few non- SafeHandle types need to implement finalizers; most disposable pattern implementations only end up wrapping other managed resources, some of which may be SafeHandle s. The following derived classes in the Microsoft. SafeHandles namespace provide safe handles:. The IDisposable interface requires the implementation of a single parameterless method, Dispose.

Also, any non-sealed class should have an additional Dispose bool overload method. Because the public , non-virtual NotOverridable in Visual Basic , parameterless Dispose method is called when it is no longer needed by a consumer of the type , its purpose is to free unmanaged resources, perform general cleanup, and to indicate that the finalizer, if one is present, doesn't have to run. Freeing the actual memory associated with a managed object is always the domain of the garbage collector.

Because of this, it has a standard implementation:. The Dispose method performs all object cleanup, so the garbage collector no longer needs to call the objects' Object. Finalize override. Therefore, the call to the SuppressFinalize method prevents the garbage collector from running the finalizer. If the type has no finalizer, the call to GC.

SuppressFinalize has no effect. Note that the actual cleanup is performed by the Dispose bool method overload. In the overload, the disposing parameter is a Boolean that indicates whether the method call comes from a Dispose method its value is true or from a finalizer its value is false.

The disposing parameter should be false when called from a finalizer, and true when called from the IDisposable. Dispose method. In other words, it is true when deterministically called and false when non-deterministically called.