SessionParameter Class
Binds the value of a session variable to a parameter object.
Assembly: System.Web (in System.Web.dll)
The SessionParameter type exposes the following members.
| Name | Description | |
|---|---|---|
![]() | SessionParameter() | Initializes a new unnamed instance of the SessionParameter class. |
![]() | SessionParameter(SessionParameter) | Initializes a new instance of the SessionParameter class with the values of the instance specified by the original parameter. |
![]() | SessionParameter(String, String) | Initializes a new named instance of the SessionParameter class, using the specified string to identify which session state name/value pair to bind to. |
![]() | SessionParameter(String, DbType, String) | Initializes a new instance of the SessionParameter class, by using the specified name and type, and binding the parameter to the specified session state name/value pair. This constructor is for database types. |
![]() | SessionParameter(String, TypeCode, String) | Initializes a new named and strongly typed instance of the SessionParameter class, using the specified string to identify which session state name/value pair to bind to. |
| Name | Description | |
|---|---|---|
![]() | ConvertEmptyStringToNull | Gets or sets a value indicating whether the value that the Parameter object is bound to should be converted to nullptr if it is String::Empty. (Inherited from Parameter.) |
![]() | DbType | Gets or sets the database type of the parameter. (Inherited from Parameter.) |
![]() | DefaultValue | Specifies a default value for the parameter, should the value that the parameter is bound to be uninitialized when the Evaluate method is called. (Inherited from Parameter.) |
![]() | Direction | Indicates whether the Parameter object is used to bind a value to a control, or the control can be used to change the value. (Inherited from Parameter.) |
![]() | IsTrackingViewState | Gets a value indicating whether the Parameter object is saving changes to its view state. (Inherited from Parameter.) |
![]() | Name | Gets or sets the name of the parameter. (Inherited from Parameter.) |
![]() | SessionField | Gets or sets the name of the session variable that the parameter binds to. |
![]() | Size | Gets or sets the size of the parameter. (Inherited from Parameter.) |
![]() | Type | Gets or sets the type of the parameter. (Inherited from Parameter.) |
![]() | ViewState | Gets a dictionary of state information that allows you to save and restore the view state of a Parameter object across multiple requests for the same page. (Inherited from Parameter.) |
| Name | Description | |
|---|---|---|
![]() | Clone | Returns a duplicate of the current SessionParameter instance. (Overrides Parameter::Clone().) |
![]() | Equals(Object) | Determines whether the specified Object is equal to the current Object. (Inherited from Object.) |
![]() | Evaluate | Updates and returns the value of the SessionParameter object. (Overrides Parameter::Evaluate(HttpContext, Control).) |
![]() | Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.) |
![]() | GetDatabaseType | Gets the DbType value that is equivalent to the CLR type of the current Parameter instance. (Inherited from Parameter.) |
![]() | GetHashCode | Serves as a hash function for a particular type. (Inherited from Object.) |
![]() | GetType | Gets the Type of the current instance. (Inherited from Object.) |
![]() | LoadViewState | Restores the data source view's previously saved view state. (Inherited from Parameter.) |
![]() | MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
![]() | OnParameterChanged | Calls the OnParametersChanged method of the ParameterCollection collection that contains the Parameter object. (Inherited from Parameter.) |
![]() | SaveViewState | Saves the changes to the Parameter object's view state since the time the page was posted back to the server. (Inherited from Parameter.) |
![]() | SetDirty | Marks the Parameter object so its state will be recorded in view state. (Inherited from Parameter.) |
![]() | ToString | Converts the value of this instance to its equivalent string representation. (Inherited from Parameter.) |
![]() | TrackViewState | Causes the Parameter object to track changes to its view state so they can be stored in the control's ViewState object and persisted across requests for the same page. (Inherited from Parameter.) |
| Name | Description | |
|---|---|---|
![]() ![]() | ICloneable::Clone | Returns a duplicate of the current Parameter instance. (Inherited from Parameter.) |
![]() ![]() | IStateManager::IsTrackingViewState | Infrastructure. Gets a value indicating whether the Parameter object is saving changes to its view state. (Inherited from Parameter.) |
![]() ![]() | IStateManager::LoadViewState | Infrastructure. Restores the data source view's previously saved view state. (Inherited from Parameter.) |
![]() ![]() | IStateManager::SaveViewState | Infrastructure. Saves the changes to the Parameter object's view state since the time the page was posted back to the server. (Inherited from Parameter.) |
![]() ![]() | IStateManager::TrackViewState | Infrastructure. Causes the Parameter object to track changes to its view state so they can be stored in the control's ViewState object and persisted across requests for the same page. (Inherited from Parameter.) |
A SessionParameter object is typically used in order to include the value of an HttpSessionState variable in the Where clause of a database query. The SessionField property identifies the session variable from which the SessionParameter retrieves a value.
Note |
|---|
Controls that bind data to a parameter by using a SessionParameter object might throw an exception if the specified session variable is not set. To avoid this error (where appropriate), set the DefaultValue property. |
The following example shows how to use a SessionParameter object. The example assumes that another page has stored an employee ID value in a session variable named empid. The example page uses the empid session variable in the Where clause of a query and displays the result of the query in a GridView control. Because the DefaultValue property of the SessionParameter object is set to 5, data for the record that has the employeeID value of 5 will still be displayed if no session variable named empid is set before you run the example.
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.







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