HttpApplicationState Class
Enables sharing of global information across multiple sessions and requests within an ASP.NET application.
System.Collections.Specialized::NameObjectCollectionBase
System.Web::HttpApplicationState
Assembly: System.Web (in System.Web.dll)
The HttpApplicationState type exposes the following members.
| Name | Description | |
|---|---|---|
![]() | AllKeys | Gets the access keys in the HttpApplicationState collection. |
![]() | Contents | Gets a reference to the HttpApplicationState object. |
![]() | Count | Gets the number of objects in the HttpApplicationState collection. (Overrides NameObjectCollectionBase::Count.) |
![]() | IsReadOnly | Gets or sets a value indicating whether the NameObjectCollectionBase instance is read-only. (Inherited from NameObjectCollectionBase.) |
![]() | Item[Int32] | Gets a single HttpApplicationState object by index. |
![]() | Item[String] | Gets the value of a single HttpApplicationState object by name. |
![]() | Keys | Gets a NameObjectCollectionBase::KeysCollection instance that contains all the keys in the NameObjectCollectionBase instance. (Inherited from NameObjectCollectionBase.) |
![]() | StaticObjects | Gets all objects declared by an <object> tag where the scope is set to "Application" within the ASP.NET application. |
| Name | Description | |
|---|---|---|
![]() | Add | Adds a new object to the HttpApplicationState collection. |
![]() | BaseAdd | Adds an entry with the specified key and value into the NameObjectCollectionBase instance. (Inherited from NameObjectCollectionBase.) |
![]() | BaseClear | Removes all entries from the NameObjectCollectionBase instance. (Inherited from NameObjectCollectionBase.) |
![]() | BaseGet(Int32) | Gets the value of the entry at the specified index of the NameObjectCollectionBase instance. (Inherited from NameObjectCollectionBase.) |
![]() | BaseGet(String) | Gets the value of the first entry with the specified key from the NameObjectCollectionBase instance. (Inherited from NameObjectCollectionBase.) |
![]() | BaseGetAllKeys | Returns a String array that contains all the keys in the NameObjectCollectionBase instance. (Inherited from NameObjectCollectionBase.) |
![]() | BaseGetAllValues() | Returns an Object array that contains all the values in the NameObjectCollectionBase instance. (Inherited from NameObjectCollectionBase.) |
![]() | BaseGetAllValues(Type) | Returns an array of the specified type that contains all the values in the NameObjectCollectionBase instance. (Inherited from NameObjectCollectionBase.) |
![]() | BaseGetKey | Gets the key of the entry at the specified index of the NameObjectCollectionBase instance. (Inherited from NameObjectCollectionBase.) |
![]() | BaseHasKeys | Gets a value indicating whether the NameObjectCollectionBase instance contains entries whose keys are not nullptr. (Inherited from NameObjectCollectionBase.) |
![]() | BaseRemove | Removes the entries with the specified key from the NameObjectCollectionBase instance. (Inherited from NameObjectCollectionBase.) |
![]() | BaseRemoveAt | Removes the entry at the specified index of the NameObjectCollectionBase instance. (Inherited from NameObjectCollectionBase.) |
![]() | BaseSet(Int32, Object) | Sets the value of the entry at the specified index of the NameObjectCollectionBase instance. (Inherited from NameObjectCollectionBase.) |
![]() | BaseSet(String, Object) | Sets the value of the first entry with the specified key in the NameObjectCollectionBase instance, if found; otherwise, adds an entry with the specified key and value into the NameObjectCollectionBase instance. (Inherited from NameObjectCollectionBase.) |
![]() | Clear | Removes all objects from an HttpApplicationState collection. |
![]() | Equals(Object) | Determines whether the specified Object is equal to the current Object. (Inherited from Object.) |
![]() | Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.) |
![]() | Get(Int32) | Gets an HttpApplicationState object by numerical index. |
![]() | Get(String) | Gets an HttpApplicationState object by name. |
![]() | GetEnumerator | Returns an enumerator that iterates through the NameObjectCollectionBase. (Inherited from NameObjectCollectionBase.) |
![]() | GetHashCode | Serves as a hash function for a particular type. (Inherited from Object.) |
![]() | GetKey | Gets an HttpApplicationState object name by index. |
![]() | GetObjectData | Implements the ISerializable interface and returns the data needed to serialize the NameObjectCollectionBase instance. (Inherited from NameObjectCollectionBase.) |
![]() | GetType | Gets the Type of the current instance. (Inherited from Object.) |
![]() | Lock | Locks access to an HttpApplicationState variable to facilitate access synchronization. |
![]() | MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
![]() | OnDeserialization | Implements the ISerializable interface and raises the deserialization event when the deserialization is complete. (Inherited from NameObjectCollectionBase.) |
![]() | Remove | Removes the named object from an HttpApplicationState collection. |
![]() | RemoveAll | Removes all objects from an HttpApplicationState collection. |
![]() | RemoveAt | Removes an HttpApplicationState object from a collection by index. |
![]() | Set | Updates the value of an object in an HttpApplicationState collection. |
![]() | ToString | Returns a string that represents the current object. (Inherited from Object.) |
![]() | UnLock | Unlocks access to an HttpApplicationState variable to facilitate access synchronization. |
| Name | Description | |
|---|---|---|
![]() ![]() | ICollection::CopyTo | Copies the entire NameObjectCollectionBase to a compatible one-dimensional Array, starting at the specified index of the target array. (Inherited from NameObjectCollectionBase.) |
![]() ![]() | ICollection::IsSynchronized | Gets a value indicating whether access to the NameObjectCollectionBase object is synchronized (thread safe). (Inherited from NameObjectCollectionBase.) |
![]() ![]() | ICollection::SyncRoot | Gets an object that can be used to synchronize access to the NameObjectCollectionBase object. (Inherited from NameObjectCollectionBase.) |
An ASP.NET application is the sum of all files, pages, handlers, modules, and code within the scope of a virtual directory and its subdirectories on a single Web server.
A single instance of an HttpApplicationState class is created the first time a client requests any URL resource from within a particular ASP.NET application virtual directory. A separate single instance is created for each ASP.NET application on a Web server. A reference to each instance is then exposed via the intrinsic Application object.
Application state is not shared across either a Web farm (in which an application is hosted across multiple servers) or a Web garden (in which an application is hosted across multiple processes on the same computer).
| Topic | Location |
|---|---|
| How to: Save Values in Application State | Building ASP .NET Web Applications |
| How to: Read Values from Application State | Building ASP .NET Web Applications |
| How to: Save Values in Application State | Building ASP .NET Web Applications |
| How to: Read Values from Application State | Building ASP .NET Web Applications |
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.






