ASP.NET 4 Unleased - p 45 pdf

The CookieParameter includes all the properties of the base Parameter class and the following additional property:.. Using the ASP.NET FormParameter Object The FormParameter object repre

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Text=’<%# Bind(“Comments”) %>’

TextMode=”MultiLine”

Columns=”60”

Rows=”4”

Runat=”server” />

<asp:Button

id=”btnSubmit”

Text=”Submit”

CommandName=”Insert”

</InsertItemTemplate>

</asp:FormView>

<hr />

<asp:GridView

id=”grdGuestBook”

DataSourceID=”srcGuestBook”

<asp:SqlDataSource

id=”srcGuestBook”

SelectCommand=”SELECT * FROM GuestBook ORDER BY Id DESC”

InsertCommand=”INSERT GuestBook (IPAddress,Name,Comments)

VALUES (@IPAddress,@Name,

ConnectionString=”<%$ ConnectionStrings:GuestBook %>”

Runat=”server”>

<asp:ControlParameter Name=”IPAddress” ControlID=” page”

PropertyName=”IPAddress” />

</InsertParameters>

</asp:SqlDataSource>

</div>

</form>

</body>

</html>

The ControlID property is set to the value page This value is the automatically

gener-ated ID for the Page class The PropertyName property has the value IPAddress This

prop-erty is defined in the page

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Using the ASP.NET CookieParameter Object

The CookieParameter object represents a browser-side cookie The CookieParameter

includes all the properties of the base Parameter class and the following additional property:

CookieName—The name of the browser cookie

The page in Listing 9.19 illustrates how you can use the CookieParameter object The page

contains a voting form that you can use to vote for your favorite color A cookie is added

to the user’s browser to identify the user and prevent someone from cheating by voting

more than once (see Figure 9.12)

<%@ Page Language=”C#” %>

<!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.1//EN”

“http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd”>

void Page_Load()

{

if (Request.Cookies[“VoterId”] == null)

{

string identifier = Guid.NewGuid().ToString();

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HttpCookie voteCookie = new HttpCookie(“VoterId”, identifier);

voteCookie.Expires = DateTime.MaxValue;

Response.AppendCookie(voteCookie);

}

</script>

</head>

<body>

<div>

<asp:FormView

id=”frmVote”

DataSourceID=”srcVote”

DefaultMode=”Insert”

Runat=”server”>

<asp:Label

id=”lblFavoriteColor”

AssociatedControlID=”rdlFavoriteColor”

<asp:RadioButtonList

id=”rdlFavoriteColor”

SelectedValue=’<%#Bind(“Color”)%>’

Runat=”server”>

<asp:ListItem Value=”Red” Text=”Red” Selected=”True” />

<asp:ListItem Value=”Blue” Text=”Blue” />

<asp:ListItem Value=”Green” Text=”Green” />

</asp:RadioButtonList>

<br />

<asp:Button

id=”btnSubmit”

Text=”Submit”

</asp:FormView>

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<hr />

<asp:GridView

id=”grdVote”

DataSourceID=”srcVote”

<asp:SqlDataSource

id=”srcVote”

SelectCommand=”SELECT * FROM Vote

ORDER BY Id DESC”

InsertCommand=”INSERT Vote (VoterId,Color)

VALUES (@VoterId,@Color)”

ConnectionString=”<%$ ConnectionStrings:Vote %>”

Runat=”server”>

<asp:CookieParameter Name=”VoterId”

CookieName=”VoterId” />

</InsertParameters>

</div>

</form>

</body>

</html>

The cookie is added in the Page_Load() method A unique identifier (GUID) is generated

to identify the user uniquely

Using the ASP.NET FormParameter Object

The FormParameter object represents a form field submitted to the server Typically, you

never work directly with browser form fields because their functionality is encapsulated in

the ASP.NET form controls

The page in Listing 9.20 contains a client-side HTML form that enables you to enter a

movie title and director When the form is submitted to the server, the values of the form

fields are saved to the Movies database table (see Figure 9.13)

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void Page_Load()

{

if (Request.Form[“AddMovie”] != null)

srcMovies.Insert();

}

</script>

<title>Show FormParameter</title>

</head>

<body>

<label for=”txtTitle”>Movie Title:</label>

<br />

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<label for=”txtDirector”>Movie Director:</label>

<br />

</form>

<div>

<asp:GridView

id=”grdMovies”

DataSourceID=”srcMovies”

<asp:SqlDataSource

id=”srcMovies”

SelectCommand=”SELECT * FROM Movies”

InsertCommand=”INSERT Movies (Title,Director,CategoryId,DateReleased)

VALUES (@Title,@Director,0,’12/25/1966’)”

ConnectionString=”<%$ ConnectionStrings:Movies %>”

Runat=”server”>

<asp:FormParameter Name=”Title”

FormField=”txtTitle” DefaultValue=”Untitled” />

<asp:FormParameter Name=”Director”

FormField=”txtDirector” DefaultValue=”Allen Smithee” />

</InsertParameters>

</div>

</form>

</body>

</html>

You check whether a form field named AddMovie exists in the Page_Load() method This

is the name of the submit button If this field exists, you know that the client-side form

was submitted and the SqlDataSource control’s Insert() method can be called to add the

form fields to the database

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Using the ASP.NET ProfileParameter Object

The ProfileParameter object enables you to represent any of the properties of the

Profile object The ProfileParameter includes all the properties of the Parameter class

and the following property:

PropertyName—Indicates the namex of the Profile property associated with this

ProfileParameter

For example, imagine that you build a Guest Book application and you want to allow users

to enter their display names when adding entries to a guest book You can add a

DisplayName property to the Profile object with the web configuration file in Listing 9.21

<?xml version=”1.0”?>

<add name=”GuestBook” connectionString=”Data Source=.\SQLEXPRESS;

AttachDbFilename=|DataDirectory|GuestBookDB.mdf;

Integrated Security=True;User Instance=True” />

</connectionStrings>

<system.web>

</properties>

</profile>

</system.web>

</configuration>

NOTE

The Profile object automatically stores user-specific information across visits to a

website The Profile object is discussed in detail in Chapter 28, “Maintaining

Application State.”

The web configuration file in Listing 9.21 includes the definition of a Profile property

named DisplayName The default value of this property is Anonymous

The page in Listing 9.22 uses the ProfileParameter object to read the value of the

DisplayName property automatically when new entries are added to a Guest Book

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<title>Show ProfileParameter</title>

</head>

<body>

<div>

<asp:FormView

id=”frmGuestBook”

DefaultMode=”Insert”

Runat=”server”>

<asp:Label

id=”lblComments”

Text=”Enter Your Comments:”

<br />

<asp:TextBox

id=”txtComments”

Text=’<%# Bind(“Comments”) %>’

TextMode=”MultiLine”

Columns=”50”

Rows=”4”

<br />

<asp:Button

id=”btnInsert”

Text=”Add Comments”

</asp:FormView>

<hr />

<asp:GridView

id=”grdGuestBook”

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<asp:SqlDataSource

id=”srcGuestBook”

SelectCommand=”SELECT Name,Comments,EntryDate

FROM GuestBook ORDER BY Id DESC”

InsertCommand=”INSERT GuestBook (Name,Comments)

VALUES (@Name,@Comments)”

ConnectionString=”<%$ ConnectionStrings:GuestBook %>”

Runat=”server”>

<asp:ProfileParameter Name=”Name” PropertyName=”DisplayName” />

</InsertParameters>

</div>

</form>

</body>

</html>

The SqlDataSource control in Listing 9.22 includes a ProfileParameter object This object

represents the DisplayName profile property

Using the QueryStringParameter Object

The QueryStringParameter object can represent any query string passed to a page The

QueryStringParameter class includes all the properties of the base Parameter class with

the addition of the following property:

QueryStringField—The name of the query string that the QueryStringParameter

represents

This type of parameter is particularly useful when you build Master/Detail pages For

example, the page in Listing 9.23 displays a list of movie titles Each movie title links to a

page that contains detailed information for the movie

<title>Show QueryStringParameter Master</title>

</head>

<body>

<div>

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<asp:GridView

id=”grdMovies”

DataSourceId=”srcMovies”

AutoGenerateColumns=”false”

ShowHeader=”false”

Runat=”server”>

<asp:HyperLinkField

DataTextField=”Title”

DataNavigateUrlFields=”Id”

DataNavigateUrlFormatString=

➥“ShowQueryStringParameterDetails.aspx?id={0}” />

</Columns>

</asp:GridView>

<asp:SqlDataSource

id=”srcMovies”

SelectCommand=”SELECT * FROM Movies”

ConnectionString=”<%$ ConnectionStrings:Movies %>”

</div>

</form>

</body>

</html>

The ID of the movie is passed to the ShowQueryStringParameterDetails.aspx page The

movie ID is passed in a query string field named id

The page in Listing 9.24 displays detailed information for a particular movie

<title>Show QueryStringParameter Details</title>

</head>

<body>

<div>

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