You can’t really “prevent” IDisposable from spreading. Some classes need to be disposed, like AutoResetEvent, and the most efficient way is to do it in the Dispose() method to avoid the overhead of finalizers. But this method must be called somehow, so exactly as in your example the classes that encapsulate or contain IDisposable have … Read more
The .Net Garbage Collector calls the Object.Finalize method of an object on garbage collection. By default this does nothing and must be overidden if you want to free additional resources. Dispose is NOT automatically called and must be explicity called if resources are to be released, such as within a ‘using’ or ‘try finally’ block … Read more
Classic sync using Classic using calls the Dispose() method of an object implementing the IDisposable interface. using var disposable = new Disposable(); // Do Something… Is equivalent to IDisposable disposable = new Disposable(); try { // Do Something… } finally { disposable.Dispose(); } New async await using The new await using calls and await the … Read more
A quick jump into Reflector.NET shows that the Close() method on StreamWriter is: public override void Close() { this.Dispose(true); GC.SuppressFinalize(this); } And StreamReader is: public override void Close() { this.Dispose(true); } The Dispose(bool disposing) override in StreamReader is: protected override void Dispose(bool disposing) { try { if ((this.Closable && disposing) && (this.stream != null)) { … Read more
Yes, Dispose() is only called on non-null objects: http://msdn.microsoft.com/en-us/library/yh598w02.aspx
Here are a couple of discussions explaining why Dispose is not necessary for a DataSet. To Dispose or Not to Dispose ?: The Dispose method in DataSet exists ONLY because of side effect of inheritance– in other words, it doesn’t actually do anything useful in the finalization. Should Dispose be called on DataTable and DataSet … Read more
As several others have pointed out in general this is not a problem. The only case it will cause you issues is if you return in the middle of a using statement and additionally return the in using variable. But then again, this would also cause you issues even if you didn’t return and simply … Read more
SuppressFinalize should only be called by a class that has a finalizer. It’s informing the Garbage Collector (GC) that this object was cleaned up fully. The recommended IDisposable pattern when you have a finalizer is: public class MyClass : IDisposable { private bool disposed = false; protected virtual void Dispose(bool disposing) { if (!disposed) { … Read more
The general consensus is that you do not (should not) need to dispose of HttpClient. Many people who are intimately involved in the way it works have stated this. See Darrel Miller’s blog post and a related SO post: HttpClient crawling results in memory leak for reference. I’d also strongly suggest that you read the … Read more
The recommended IDisposable pattern is here. When programming a class that uses IDisposable, generally you should use two patterns: When implementing a sealed class that doesn’t use unmanaged resources, you simply implement a Dispose method as with normal interface implementations: public sealed class A : IDisposable { public void Dispose() { // get rid of … Read more