CookieParameter Class

Reference

Definition

Namespace:: System.Web.UI.WebControls

Assembly:: System.Web.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Binds the value of a client-side HTTP cookie to a parameter object. The parameter can be used in a parameterized query or command to select, filter, or update data.

public ref class CookieParameter : System::Web::UI::WebControls::Parameter

public class CookieParameter : System.Web.UI.WebControls.Parameter

type CookieParameter = class
    inherit Parameter

Public Class CookieParameter
Inherits Parameter

Inheritance: Object

Parameter
CookieParameter

Examples

The following code example demonstrates how to use a SqlDataSource control and CookieParameter object bound to an HTTP cookie to display data from the Northwind Traders database in a GridView control.

<%@Page  Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

void Page_Load(Object sender, EventArgs e){
  // These cookies might be added by a login form.
  // They are added here for simplicity.
  if (!IsPostBack) {
      Response.Cookies.Add(new HttpCookie("lname",    "davolio"));
      Response.Cookies.Add(new HttpCookie("loginname","ndavolio"));
      Response.Cookies.Add(new HttpCookie("lastvisit", DateTime.Now.ToString()));
  }
}


</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
    <form id="form1" runat="server">

      <asp:SqlDataSource
          id="SqlDataSource1"
          runat="server"
          DataSourceMode="DataSet"
          ConnectionString="<%$ ConnectionStrings:MyNorthwind%>"
          SelectCommand = "SELECT OrderID,CustomerID,OrderDate,RequiredDate,ShippedDate 
                           FROM Orders WHERE EmployeeID = 
                           (SELECT EmployeeID FROM Employees WHERE LastName = @lastname)">
          <SelectParameters>
            <asp:CookieParameter Name="lastname" CookieName="lname" />
          </SelectParameters>
      </asp:SqlDataSource>

      <asp:GridView
          id="GridView1"
          runat="server"
          AllowSorting="True"
          DataSourceID="SqlDataSource1">
      </asp:GridView>

    </form>
  </body>
</html>

<%@Page  Language="VB" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

Sub Page_Load(sender As Object, e As EventArgs)
  ' These cookies might be added by a login form.
  ' They are added here for simplicity.
  If (Not IsPostBack) Then
      Dim cookie As HttpCookie

      cookie = New HttpCookie("lname","davolio")
      Response.Cookies.Add(cookie)

      cookie = New HttpCookie("loginname","ndavolio")
      Response.Cookies.Add(cookie)

      cookie = New HttpCookie("lastvisit", DateTime.Now.ToString())
      Response.Cookies.Add(cookie)
  End If
End Sub ' Page_Load
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
    <form id="form1" runat="server">

      <asp:SqlDataSource
          id="SqlDataSource1"
          runat="server"
          DataSourceMode="DataSet"
          ConnectionString="<%$ ConnectionStrings:MyNorthwind%>"
          SelectCommand = "SELECT OrderID,CustomerID,OrderDate,RequiredDate,ShippedDate 
                           FROM Orders WHERE EmployeeID = 
                           (SELECT EmployeeID FROM Employees WHERE LastName = @lastname)">
          <SelectParameters>                 
            <asp:CookieParameter Name="lastname" CookieName="lname" />
          </SelectParameters>
      </asp:SqlDataSource>

      <asp:GridView
          id="GridView1"
          runat="server"
          AllowSorting="True"
          DataSourceID="SqlDataSource1">
      </asp:GridView>

    </form>
  </body>
</html>

Remarks

You can use the CookieParameter class to bind the value of a client-side HTTP cookie passed as part of an HTTP request to a parameter used by ASP.NET data source controls.

The CookieParameter class provides the CookieName property, which identifies the name of the HttpCookie object to bind to, in addition to those inherited from the Parameter class. The CookieParameter class attempts to bind to the named cookie every time the Evaluate method is called.

Important

Controls that bind data to the parameter might throw an exception if a CookieParameter object is specified, but no corresponding cookie is passed with the HTTP request. Similarly, they might display no data if the cookie is passed with null. Set the DefaultValue property to avoid these situations where appropriate.

Constructors

CookieParameter()	Initializes a new unnamed instance of the CookieParameter class.
CookieParameter(CookieParameter)	Initializes a new instance of the CookieParameter class with the values of the instance specified by the `original` parameter.
CookieParameter(String, DbType, String)	Initializes a new instance of the CookieParameter class that has the specified name and database type and that is bound to the specified HTTP cookie.
CookieParameter(String, String)	Initializes a new named instance of the CookieParameter class, using the specified string to identify which HTTP cookie to bind to.
CookieParameter(String, TypeCode, String)	Initializes a new named and strongly typed instance of the CookieParameter class, using the specified string to identify which HTTP cookie to bind to.

Properties

ConvertEmptyStringToNull	Gets or sets a value indicating whether the value that the Parameter object is bound to should be converted to `null` if it is Empty. (Inherited from Parameter)
CookieName	Gets or sets the name of the HTTP cookie that the parameter binds to.
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(HttpContext, Control) 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)
Size	Gets or sets the size of the parameter. (Inherited from Parameter)
Type	Gets or sets the type of the parameter. (Inherited from Parameter)
ValidateInput	Gets or sets a value that specifies whether the parameter's value is validated.
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)

Methods

Clone()	Returns a duplicate of the current CookieParameter instance.
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
Evaluate(HttpContext, Control)	Updates and returns the value of the CookieParameter object.
GetDatabaseType()	Gets the DbType value that is equivalent to the CLR type of the current Parameter instance. (Inherited from Parameter)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetType()	Gets the Type of the current instance. (Inherited from Object)
LoadViewState(Object)	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(EventArgs) 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)

Explicit Interface Implementations

ICloneable.Clone()	Returns a duplicate of the current Parameter instance. (Inherited from Parameter)
IStateManager.IsTrackingViewState	Gets a value indicating whether the Parameter object is saving changes to its view state. (Inherited from Parameter)
IStateManager.LoadViewState(Object)	Restores the data source view's previously saved view state. (Inherited from Parameter)
IStateManager.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)
IStateManager.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)

Applies to

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