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//------------------------------------------------------------------------------
// <copyright file="SessionParameter.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//------------------------------------------------------------------------------
namespace System.Web.UI.WebControls {
using System;
using System.ComponentModel;
using System.Data;
/// <devdoc>
/// Represents a Parameter that gets its value from the application's session state.
/// </devdoc>
[
DefaultProperty("SessionField"),
]
public class SessionParameter : Parameter {
/// <devdoc>
/// Creates an instance of the SessionParameter class.
/// </devdoc>
public SessionParameter() {
}
/// <devdoc>
/// Creates an instance of the SessionParameter class with the specified parameter name, and session field.
/// </devdoc>
public SessionParameter(string name, string sessionField) : base(name) {
SessionField = sessionField;
}
/// <devdoc>
/// Creates an instance of the SessionParameter class with the specified parameter name, database type, and
/// session field.
/// </devdoc>
public SessionParameter(string name, DbType dbType, string sessionField)
: base(name, dbType) {
SessionField = sessionField;
}
/// <devdoc>
/// Creates an instance of the SessionParameter class with the specified parameter name, type, and session field.
/// </devdoc>
public SessionParameter(string name, TypeCode type, string sessionField) : base(name, type) {
SessionField = sessionField;
}
/// <devdoc>
/// Used to clone a parameter.
/// </devdoc>
protected SessionParameter(SessionParameter original) : base(original) {
SessionField = original.SessionField;
}
/// <devdoc>
/// The name of the session variable to get the value from.
/// </devdoc>
[
DefaultValue(""),
WebCategory("Parameter"),
WebSysDescription(SR.SessionParameter_SessionField),
]
public string SessionField {
get {
object o = ViewState["SessionField"];
if (o == null)
return String.Empty;
return (string)o;
}
set {
if (SessionField != value) {
ViewState["SessionField"] = value;
OnParameterChanged();
}
}
}
/// <devdoc>
/// Creates a new SessionParameter that is a copy of this SessionParameter.
/// </devdoc>
protected override Parameter Clone() {
return new SessionParameter(this);
}
/// <devdoc>
/// Returns the updated value of the parameter.
/// </devdoc>
protected internal override object Evaluate(HttpContext context, Control control) {
if (context == null || context.Session == null) {
return null;
}
return context.Session[SessionField];
}
}
}
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