idisposable

问题 In my Dispose methods (like the one below), everytime i want to call someObj.Dispose() i also have a check for someObj!=null. Is that because of bad design on my part? Is their a cleaner way to ascertain that Dispose of all the members (implementing IDisposable) being used in an object is called without having a risk of NullReference exception ? protected void Dispose(bool disposing) { if (disposing) { if (_splitTradePopupManager != null) { _splitTradePopupManager.Dispose(); } } } Thanks for

问题 I'm writing an IEnumerator<T> class to iterate over a COM collection I'm wrappering. I've noticed that IEnumerator<T> extends IDisposable, so I'm required to implement the Dispose method. However, I can't think of anything I would put there, as I only have a reference to the collection (which I wouldn't want being disposed at the end of a foreach ), and an int for the index. Is it normal to leave the Dispose method empty? 回答1: Yes, it is. IEnumerator<T> implements IDisposable in case you make

问题 I have a web service that is quite heavy on database access. It works fine in test, but as soon as I put it in production and ramp up the load it starts churning out errors that are raised when something calls a method in the DataContext. The error is normally one of these: Object reference not set to an instance of an object Cannot access a disposed object. Object name: 'DataContext accessed after Dispose.'. but not always. Any single web service requests can result as many as 10 or 15

问题 I am working on a class that deals with a lot of Sql objects - Connection, Command, DataAdapter, CommandBuilder, etc. There are multiple instances where we have code like this: if( command != null ) { command.Dispose(); } if( dataAdapter != null ) { dataAdapter.Dispose(); } etc I know this is fairly insufficient in terms of duplication, but it has started smelling. The reason why I think it smells is because in some instances the object is also set to null. if( command != null ) { command

问题 I understand it is best practise to call Dispose() on instances of Pen and Brush, except if they've been set to the system-predefined values (eg. System.Drawing.Brushes, System.Drawing.Pens or System.Drawing.SystemBrushes) Trying to dispose a system-defined resource results in an exception being thrown. It doesn't appear to be obvious how you can detect (apart from wrapping the Dispose() call in a try/catch) whether one of these resources is referencing a system-defined or user-defined value.

问题 I'm currently learning how to use Autofac, and I'm stuck with disposing IDisposable objects deterministically. Let me first present the situation before I'll state my problem. Starting position: Let's say my object model is defined through the following interfaces: interface IApple : IDisposable { void Consume(); } interface IHorse { void Eat(IApple apple); // is supposed to call apple.Consume() } interface IHorseKeeper { void FeedHorse(); // is supposed to call horse.Eat(apple) // where

问题 I have the following ADO .Net Repository public class Repository : IRepository, IDisposable { private readonly IUnitOfWork UnitOfWork; private SqlConnection Connection; public Repository(IUnitOfWork unitOfWork, connectionString) { UnitOfWork = unitOfWork; Connection = new SqlConnection(connectionString); Connection.Open(); } public MyObject FindBy(string userName) { //...Ado .Net command.ExecuteReader, etc. } } This repository is injected with an IoC container to a Domain Service and is used

问题 I'm trying to Dispose of an IDisposable object(FileStream^ fs) in managed C++ (.Net 2.0) and am getting the error 'Dispose' : is not a member of 'System::IO::FileStream' It says that I should invoke the destructor instead. Will calling fs->~FileStream(); call the dispose method on the FileStream object? Why can't I call Dispose? 回答1: The correct pattern is to just delete the object: delete fs; This will be translated into a call to Dispose() See this post for some of the details of what is

问题 I can never remember all the rules for implementing the IDisposable interface, so I tried to come up with a base class that takes care of all of this and makes IDisposable easy to implement. I just wanted to hear your opinion if this implementation is ok as it is or whether you see something I could improve. The user of this base class is supposed to derive from it and then implement the two abstract methods ReleaseManagedResources() and ReleaseUnmanagedResources() . So here is the code:

问题 I am trying to dispose XmlWriter object: try { [System.Xml.XmlWriter] $writer = [System.Xml.XmlWriter]::Create('c:\some.xml') } finally { $writer.Dispose() } Error: Method invocation failed because [System.Xml.XmlWellFormedWriter] doesn't contain a method named 'Dispose'. On the other side: $writer -is [IDisposable] # True What should I do? 回答1: Dispose is protected on System.Xml.XmlWriter . You should use Close instead. $writer.Close 回答2: Here is an alternative approach: (get-interface $obj