Web Forms and Server Controls

1
Web Forms and Server Controls

• ASP.NET

2
Using HTML Server Controls

• All HTML tags can be changed into server-side
  tags using the attribute and value runat"server"
• Limited functionality compared to Web controls
• Provide output similar to their HTML counterparts
• To set the runat attribute
• Right-click on the HTML control and select the
  command Run As Server Control or
• Type the attribute and value into the tag in HTML
  view, i.e.
• ltinput type"text" runat"server"gt

3
HTML Server Controls

• Similar to HTML Controls but run on the server
• Divided into separate classes
• HTMLInputControl
• HTMLContainerControl

4
HTML Server Controls
5
HTML Control Client-Side vs. Server-Side Event
Handlers

• In HTML documents, client-side controls (i.e.
  scripts or procedures executing in JavaScript or
  VbScript) have events such as onClick and
  onChange
• Associated with HTML client controls
• When an HTML Server control value has changed,
  the OnServerChange or OnServerClick event occurs

6
The Line Continuation Character

• When writing code, never press ltEntergt key in the
  middle of a statement within code behind the page
• Underscore (_) key preceded by a blank space
  allows the statement to be continued on next line
• Example
• lblMaturity.InnerHtml sngInvestment _
• (1 sngRate / 36000) _
• (360 intYears)
• (Single-line statement)

7
Concatenation

• Joining of two or more strings into a single
  string using either of the operators "" or ""
• Formats
• String1 String2 -or- String3 String4
• Examples
• strString "Welcome to " "ASP.NET"
• Stores "Welcome to Visual Basic" into strString
• lblArithmetic.InnerHtml "11 7 " _
• 11 7
• Stores "11 7 18" into lblArithmetic.InnerHtml

8
HTML Server Control Event Handlers

• Controls that support the OnServerChange event
• HTMLInputCheckBox
• HTMLInputRadioButton
• HTMLInputHidden
• HTMLInputText
• HTMLTextArea
• HTMLSelect

• Controls that support the OnServerClick event
• HTMLInputImage
• HTMLAnchor
• HTMLButton
• HTMLForm

9
Starting a New Web Form

• Select Project from the menu bar
• Select Add Web Form from the Project menu
• The "Web Form" icon will already be selected in
  the Templates frame of the "New Item" dialog
  window
• Type the Name for the new file
• The extension ".aspx" will be added automatically
  when the file is created
• Click the ltOpengt button

10
HTMLButton.aspx
11
Properties

• Properties of the individual controls can be
  changed through "Properties" window
• The Style property (attribute) is modified using
  Style Builder dialog window (same as for style
  sheets)
• Additionally many properties can be changed by
  adding statements to the code behind the page
• When page loads, or when an event occurs, such as
  a button click
• Properties frequently are not the same for HTML
  server controls and ASP.NET server controls

12
"Font" Properties in Style Builder
13
"Position" Properties in Style Builder
14
HTMLButton.aspx (Page 1)

• Add the image header.jpg
• Style propertyPosition tab
• Top0 Left0
• Add the image menu.gif
• Style propertyPosition tab
• Top 85 Left 17
• Add the image waterfordgifts.jpg
• Style propertyPosition tab
• Top 38 Left 134

15
The ID and Name Properties

• The ID property is used to identify the control
  to the server for server-side processing
• The Name property identifies the control to
  scripts running on the client side

16
HTMLButton.aspx (Page 2)

• Add a Label from the "HTML" tab in the Toolbox
• Set attribute "runat server" (right-click and
  select command Run as Server Control)
• IDlblTitle
• Name(we will not be setting this property)
• Style
• Font (FamilyTrebuchet MS Size15)
• Position (Top243 Left139 Height26
  Width365)
• Modify text by typing"Select the gender of the
  gift recipient"

17
HTMLButton.aspx (Page 3)

• Add a Button from the "HTML" tab in the Toolbox
• Set attribute "runatserver"
• IDbtnMale
• Style (Top278 Left138 Height27 Width89)
• Value"Male"
• Add a Button from the "HTML" tab in the Toolbox
• Set attribute "runatserver"
• IDbtnFemale
• Style (Top310 Left138 Height27 Width89)
• Value"Female"

18
HTMLButton.aspx (Page 4)

• Add a Label from the "HTML" tab in the Toolbox
• Set attribute "runat server"
• IDlblGiftIdeasWomen
• Style
• Font (FamilyTrebuchet MS Size12)
• Position (Top275 Left235 Height210
  Width250)

19
HTMLButton.aspx (Page 5)

• LabellblGiftIdeasWomen
• Create a bulleted list
• Make-Up Brush
• Tyrone Bell
• Butterfly
• Balmoral Vase
• Abbey Clock
• Heart-Shaped Ring Holder
• Wellsley Picture

20
HTMLButton.aspx (Page 6)

• Add a Label from the "HTML" tab in the Toolbox
• Set attribute "runat server"
• IDlblGiftIdeasMen
• Style
• Font (FamilyTrebuchet MS Size12)
• Position (Top275 Left235 Height210
  Width250)
• (Wait to set the Left position until all text is
  entered)

21
HTMLButton.aspx (Page 6)

• LabellblGiftIdeasMen
• Create a bulleted list
• Golf Ball
• Golf Club
• Male Golfer
• Letter Opener
• Business Card Holder
• Shamrock Paperweight

22
Procedures

• A procedure (Sub or Function)is a named grouping
  of one or more programming statements
• Create an event Sub procedure by double-clicking
  on the object in Design mode
• The Page_Load event occurs when the web page
  loads into the browser
• Example
• Private Sub Page_Load( ) Handles MyBase.Load
• lblGiftIdeasMen.Visible False
• lblGiftIdeasWomen.Visible False
• End Sub

23
The ServerClick Event

• Occurs when an HTML Server Button (HTML Button
  with runatserver attibute set) is clicked
• Equivalent of Click event in VB .NET, but for an
  ASP.NET Web Server control
• Example
• Private Sub btnMale_ServerClick( ) Handles
  btnMale.ServerClick
• End Sub

24
The InnerHtml Property

• Modifies the contents of an HTML Label (or other)
  control
• May include HTML tags for formatting of the text
• The Label is converted to a ltdivgt tag with
  inserted text in the rendering of an HTML
  document
• Example
• lblTitle.InnerHtml "ltbgtWe have lots of gift
  ideas for men.lt/bgt"
• The InnerText property (similar to InnerHtml) may
  only contain text elements, not formatting tags

25
HTMLButton.aspxPage_Load

• Private Sub Page_Load( ) Handles MyBase.Load
• lblGiftIdeasMen.Visible False
• lblGiftIdeasWomen.Visible False
• End Sub

26
HTMLButton.aspxbtnMale_ServerClick

• Private Sub btnMale_ServerClick( ) Handles
  btnMale.ServerClick
• lblTitle.InnerHtml "ltbgtWe have lots of gift
  ideas for men.lt/bgt"
• lblGiftIdeasMen.Visible True
• lblGiftIdeasWomen.Visible False
• End Sub

27
HTMLButton.aspxbtnFemale_ServerClick

• Private Sub btnFemale_ServerClick( ) Handles
  btnFemale.ServerClick
• lblTitle.InnerHtml "ltbgtWe have lots of gift
  ideas for women.lt/bgt"
• lblGiftIdeasWomen.Visible True
• lblGiftIdeasMen.Visible False
• End Sub

28
HTML Image Button (Page 1)

• An image is displayed on the Button instead of
  text
• By default the image docks to the all sides on
  the button, so it stretches if the button is
  resized
• There actually is no Image Button in the HTML tab
  of the Toolbox
• Drop and drag an HTML Button from the Toolbox
• Then key the type attribute in the input tag,
  i.e.
• ltinput type"image"gt

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HTML Image Button (Page 2)

• The src attribute names the path and filename of
  the image file displayed on the Button, i.e.
• ltinput type"image" src"male.gif"gt
• No value attribute is required since image
  replaces the text on the button
• All other functioning is the same as the HTML
  Button control

30
HTMLImageButton.aspx
31
HTMLImageButton.aspx

• btnMale
• ltinput type"image" src"images/male.gif"gt
• btnFemale
• ltinput type"image" src"images/female.gif"gt

32
The Value Property for a Text Field

• Retrieves or modifies the values from HTML text
  field (text box) controls
• The value attribute can be used to set the
  default value for input controls such as a
  one-line text field or password box
• Used for HTML form controls rather than the Text
  property of ASP.NET server controls
• Examples
• txtUserName.Value
• txtPassword.Value

33
HTML Button Controls

• Buttons usually call procedures when clicked
• Available are Submit, Reset, and the general
  Button
• Member of the HTMLInputControl Class, i.e.
• ltinput type "Submit"gt
• ltinput type "Reset"gt
• Resets Form to default so runat"server" not
  applicable
• ltinput type "Button"gt
• Default procedure for HTML Buttons is ServerClick
  event, i.e
• Private Sub btnSubmit_ServerClick( ) Handles
  btnSubmit.ServerClick

34
HTMLInputButton.aspx
35
HTMLInputButton.aspx (Page 1)

• Add Text Field from "HTML" tab in Toolbox
• Set attribute "runat server"
• IDtxtUsername
• Style (Top280 Left145)
• Add Password Field from "HTML" tab in Toolbox
• Set attribute "runat server"
• IDtxtPassword
• Style (Top310 Left145)

36
HTMLInputButton.aspx (Page 2)

• Add Submit Button from "HTML" tab in Toolbox
• Set attribute "runat server"
• IDbtnSubmit
• Style (Top345 Left150)
• Value"Sign In"
• Add Reset Button from "HTML" tab in Toolbox
• IDbtnReset
• Style (Top345 Left230)

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HTMLInputButton.aspx (Page 3)

• Add a Button from "HTML" tab in Toolbox
• Set attribute "runat server"
• IDbtnHelp
• Style (Top345 Left450)
• Value"Help"

38
HTMLInputButton.aspxPage_Load

• Private Sub Page_Load( ) Handles MyBase.Load
• lblTitle.InnerText "Please log into our
  Customer Support Area"
• lblHelp.Visible False
• btnHelp.Visible True
• End Sub

39
HTMLInputButton.aspxPage_Load (Page 1)

• Private Sub btnSubmit_ServerClick( ) Handles
  btnSubmit.ServerClick
• lblHelp.Visible False
• If txtUsername.Text "Course" And
  txtPassword.Text "Technology" Then
• lblTitle.InnerText "You are authenticated"

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HTMLInputButton.aspxPage_Load (Page 2)

• Else
• lblTitle.InnerText "Please click on the Help
  button for help!"
• txtUsername.Text ""
• txtPassword.Text ""
• btnHelp.Visible True
• End If
• End Sub

41
HTMLInputButton.aspxbtnHelp_ServerClick

• Private Sub btnHelp_Server_Click( ) Handles
  btnHelp.ServerClick
• lblTitle.InnerText "Please log into our
  Customer Support Area"
• lblHelp.Visible True
• btnHelp.Visible False
• End Sub

42
HTML Radio Button, Dropdown List, and Hyperlink
Server Controls

• CheckBoxes, RadioButtons and DropDown lists
• Form fields that allow users to select from lists
  of options
• Can retrieve their values using properties of the
  HTML form control
• Hyperlinks
• Allow you to create links to other pages or to
  internal targets within the same page

43
The Checked Property of RadioButtons

• Determines which RadioButton is Checked
• If rdBridal.Checked True Then
• lblTitle.InnerHtml "Celebrate your Wedding!"
• imgTop.Src "images/28.jpg"
• End If
• Or
• If rdBridal.Checked Then
• lblTitle.InnerHtml "Celebrate your Wedding!"
• imgTop.Src "images/28.jpg"
• End If

44
The RadioButton HTML Server Control
45
Dropdown HTML Server Control

• Created with the HTML ltselectgt tag
• ltoptiongt tags create each individual item
• A value attribute can be associated with each
  item in the list
• SelectedIndex property of the drop-down list box
• A zero-based index indicating which item is
  selected
• When nothing has been selected the SelectedIndex
  property returns the value -1
• The Add method add items to the list dynamically
  in code when the page loads, or when an event
  occurs

46
The IsPostback Page Property

• Determines if the user has visited page before
  during the current session
• Important to know so that statements that
  initialize the page do not run again if page is
  revisited
• The _doPostBack function is generated
  automatically by ASP.NET
• Passes to the Web server information concerning
  the object that called an event and parameters
  passed to it
• The Boolean IsPostBack property recognizes if the
  page was visited previously from this information

47
The IsPostback Page Property and the Add Method
of the Select Control

• Example
• If Not Me.IsPostBack Then
• lblTitle.InnerHtml() _
• "Select gender of gift recipient."
• imgProduct.Visible False
• ProductList.Visible False
• CatList.Items.Add("Gifts for Men")
• CatList.Items.Add("Gifts for Women")
• End If

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Dropdown HTML Server Control
49
Anchors (Hyperlinks)

• Creates a hyperlink to another Web document
• Example
• lta href"http//www.tarastore.com" id"AMale"
  name"AMale" runat"server"gtMenlt/agt
• The HRef property can change the URL for an ltagt
  tag in the code behind the page, i.e.
• AMale.HRef "GiftsForMen.aspx"
• AFemale.HRef "GiftsForWomen.aspx"
• AHome.HRef "http//www.tarastore.com"

50
The Hyperlink Control
51
Using ASP.NET Web Form Controls

• Also known as Web Controls
• Located on the Web Forms tab in the Toolbox
• Inherit from the Web Control class
• ASP.NET controls can be logically grouped into
• Web Form controls
• Rich controls
• Data controls
• Validation Controls
• Mobile Controls

52
Syntax Differences for Assigning Text to a Label
in Web Form Controls

• Text is assigned to a Label (and other controls)
  using the Text property, not InnerHtml or
  InnerText
• Example
• Label1.Text "Welcome to ASP.NET"
• Web Form controls in ASP.NET follow a syntax that
  closely approximates that of Visual Basic .NET

53
Syntax Differences for Assigning Color Values in
Web Form Controls

• Color is a class in .NET Framework derived from
  the System.Drawing.Color namespace
• Assign the value using known colors referred to
  by name, i.e.
• MyControl.BorderColor System.Drawing.Color.Green
  
• MyControl.BorderColor Color.Green

54
The Color.FromName() Method

• Returns a color value from the Color class
• Values may be specific system-define color name
  or an RGB hexadecimal color value as a string
• Format
• ControlName.ColorProperty Color.FromName("System
  DefinedColor")
• Examples
• MyControl.BackColor Color.FromName("Red")
• MyControl.BackColor Color.FromName("MenuText")

55
Syntax Differences for Assigning Image Properties
in Web Form Controls

• Image control class produces an ltimggt tag
• Properties of the Image control are different
  from HTML server controls as follows
• ImageURLpath to the image and filename creates
  the src property
• AlternateTextdisplays text when the image is not
  available creates the alt property
• ImageAlignprovides the image alignment creates
  the align property

56
The Add Method for the DropDownList Web Form
Control

• Adds options (ltoptiongt blocks) to the
  DropDownList
• Member of the Items collection of the
• Example
• If Not IsPostBack Then
• dlCategory.Items.Add("Gifts")
• dlCategory.Items.Add("Jewelry")
• dlCategory.Items.Add("China and Crystal")
• dlCategory.Items.Add("Pottery")
• dlCategory.Items.Add("Clothing")
• dlCategory.Items.Add("Food")
• dlCategory.Items.Add("Books, Music, Video")
• dlCategory.Items.Add("Bridal")
• End If

57
The SelectedIndex Property of the DropDownList
Web Form Control

• The SelectedIndex property is a zero-based index
  indicating which item in the DropDownList is
  selected
• When no item has been selected from DropDownList,
  the SelectedIndex property returns the value -1
• Example
• Select Case dlCategory.SelectedIndex
• Case 0
• lblTitle.Text _
• "Let us help you find best gift!"
• imgTop.ImageUrl "images/21.jpg"

58
ASPSelect.aspx
59
ASPSelect.aspx

• In Design view, drag DropDownList control from
  "Web Forms" tab of Toolbox onto Form
• Set properties
• ID dlCategory
• Height 25
• Width 155

60
ASPSelect.aspxPage_Load

• Private Sub Page_Load( ) Handles MyBase.Load
• If Not IsPostBack Then
• dlCategory.Items.Add("Gifts")
• dlCategory.Items.Add("Jewelry")
• dlCategory.Items.Add("China and Crystal")
• dlCategory.Items.Add("Pottery")
• dlCategory.Items.Add("Clothing")
• dlCategory.Items.Add("Food")
• dlCategory.Items.Add("Books, Music, Video")
• dlCategory.Items.Add("Bridal")
• End If
• End Sub

61
ASPSelect.aspxPage_Click

• Enter the following code after the procedure
  header
• Select Case dlCategory.SelectedIndex
• Case 0
• lblTitle.Text "Let us help you find the best
  gift!"
• imgTop.ImageUrl "images/21.jpg"

62
Panel Web Form Controls

• The Panel control contains other controls and in
  the browser HTML creates a ltdivgt block
• Another method for setting properties,
  i.e.wrapping, absolute positioning, font type,
  and scrollbars
• A Label control inserted into the Panel, creates
  a ltspangt tag in the rendered HTML code
• Use the Text property to display the text
• Only allows for flow layout of elements
• Use a Table or an HTML gridlayout

63
ASPPanel.aspx
64
Literal Web Form Controls

• Used to write content directly to the page, i.e.
• Client-side HTML or text without an ID property
• The runat "server" attribute may not be applied

65
Placeholder Web Form Control

• A container to store dynamically added server
  controls
• Does not produce any visible output without
  addition of other controls
• The inserted controls are instantiated using
  classes and constructors, and are added to the
  Controls collection of the Placeholder, i.e.
• Dim MyLink As New Hyperlink
• placeholder.Controls.Add(MyLink)

66
The "Target" Property of a Hyperlink Control

• Targetwindow or frame in which the Web page will
  load (open)
• The reserved name windows are
• _blankrenders in a new window without frames
  (_new will also render in a new window)
• _parentrenders in the immediate frameset or
  window parent one level above
• _selfrenders in frame with the current focus
• _toprenders in a full window without frames
• Target also may be a named frame or window

67
ASPPlaceHolder.aspx
68
ASPPlaceHolder.aspx

• In Design view, the Placeholder control already
  is inserted onto Form
• Set properties
• ID placeholder

69
ASPPlaceHolder.aspxPage_Load

• After comment "Create a hyperlink", insert
• Dim MyLink As New Hyperlink
• placeholder.Controls.Add(MyLink)
• With MyLink
• .Text "Click here to see larger image"
• .ForeColor Color.FromName("004040")
• .Font.Name "Trebuchet MS"
• .Font.Size MyLabel.Font.Size.Smaller
• .ID "HLHome"
• .NavigateURL "images/LgButterfly.jpg"
• .Target "_blank"
• End With

70
CheckBox Web Form Control

• Unlike a RadioButton, more than one CheckBox can
  be Checked
• Code can look at the value of each CheckBox, i.e.
  
• Dim MyMessage As String
• MyMessage "ltbgtYou selectedlt/bgtltbr /gt"
• If CB1.Checked Then
• MyMessage CB1.Text "ltbr /gt"
• End If

71
ASPCheckBox.aspx
72
ASPCheckBox.aspx

• In Design view, drag CheckBox control from "Web
  Forms" tab of Toolbox below last CheckBox on Form
• Set properties
• ID CB8
• FontName Trebuchet MS
• FontSize X-Small
• ForeColor 004040
• StylePosition Top?? Left??
• Text Sports in Ireland

73
ASPCheckBox.aspxbtnSubmit_Click

• Enter the following code after the procedure
  header
• Dim MyMessage As String
• MyMessage "ltbgtYou selectedlt/bgtltbr /gt ltbr /gt"
• If CB1.Checked Then
• MyMessage CB1.Text "ltbr /gt"
• End If

74
Using Validation Controls (Page 1)

• Compare controls, or part of the controls such as
  the data, to a rule
• Rule may require that the control contain any
  value, or require a specific form of data such as
  alphabetical or numeric.
• The rule may specify what the data must be
  contained within a range of two values.
• The rule may be very specific and require
  formatting such as uppercase letters and periods.

75
Using Validation Controls (Page 2)

• The five validation controls are
• RequiredFieldValidatorMakes sure a form field is
  not left blank
• RangeValidatorMakes sure a fields value falls
  between a given range
• CompareValidatorCompares field with other values
  or values of other controls using relational
  operators
• RegularExpressionValidatorEvaluates the data
  against a regular expression
• CustomValidatorEvaluates data against custom
  criteria as defined in a programmer-define
  Function

76
Using Validation Controls (Page 3)

• Inherits from the BaseValidator class which
  inherits from the Label class
• Therefore custom error messages are displayed
  using Label controls
• Validation controls that perform comparisons
  inherit directly from BaseCompareValidator base
  class

77
Using Validation Controls (Page 4)

• Common properties
• Display propertyshows the message
• Dynamicspace for the validation message is
  dynamically added to the page only if validation
  fails
• Staticspace for the validation message is
  allocated in the page layout whether there is an
  error, or not
• Nonevalidation message is never displayed in the
  browser
• ErrorMessagedisplayed if the value of the
  control is in error (extends from Text property
  of a Label)
• ForeColor property is the color of the error
  message (default color is red)

78
Using Validation Controls (Page 5)

• Validate method performs validation on associated
  input control and updates the IsValid property
• Page.IsValid (Boolean) indicates if the controls
  on the page are valid after the Page.Validate
  method executes
• The following checks if the entire form is valid
• Page.Validate()
• If Page.IsValid Then
• Message.Text "Result Valid!"
• Else
• Message.Text "Result Not valid!"
• End If

79
Using Validation Controls (Page 6)

• ControlToValidate property specifies the control
  to validate
• For the RegularExpressionValidator control,
  theValidationExpression property compares control
  to the regular expression
• Regular Expression is a rule that describes the
  value using a language that describes one or more
  groups of characters

80
Using Validation Controls (Page 7)

• The ValidationExpression property
• Built-in regular expressions
• Regular Expression Editor
• Library of sample codes
• Internet E-Mail Address
• \w(-.\w)_at_\w(-.\w)\.\w(-.\w)
• Internet URL
• http//(\w-\.)\w-(/\w- ./?)?
• US Phone Number
• \d3-\d3-\d4
• US Zip Code
• \d5(-\d4)?

81
ASPValidateForm.aspx
82
Using Validation Controls (Page 8)

• The ValidationSummary control
• Summarizes in one location the error messages
  from all validators on a Web page
• Properties
• DisplayModeerror messages displays as a list
  (List), a bulleted list (BulletList), or a single
  paragraph (SingleParagraph)
• ShowSummaryshows the entire list
• ShowMessageBoxdisplays errors in an alert box
• HeaderTexta heading message displayed prior to
  the error listing

83
ASPValidationSummary.aspx
84
Binding Web Form Controls to Simple Data

• Bind data to controls
• Assign a DataSource
• Call the DataBind method
• Group together controls
• RadioButtonList controlsgroup RadioButtons
• CheckboxList controlsgroup CheckBox controls
• Set group properties
• RepeatDirection propertydisplayed horizontally
  or vertically
• RepeatLayout propertyuse table or paragraph tags

85
Binding RadioButtonLists to ArrayLists (Page 1)

• An ArrayList is a type of array
• Size dynamically increases as required
• Declared using Dim, the array name, and keyword
  New, and ArrayList at the type
• Properties and Methods
• Capacitythe number of items the list can hold
• zero-based - counting of items starts at 0 and
  not 1 default capacity of 16
• Countdetermines the number of items in the list
• Add methodused to add items to the list
• SelectedItemdetermines which element is selected
  

86
Binding RadioButtonLists to ArrayLists (Page 2)

• Add items to array list and populate
  RadioButtonList
• AR1.Add("Sports in Ireland")
• RBL.DataSource AR1
• RBL.DataBind()
• Retrieve values using SelectedItem property
• Dim strResult As String
• strResult "ltbgtYou selected lt/bgtltbr/gtltbr/gt"
• If RBL.SelectedIndex gt -1 Then
• strResult RBL.SelectedItem.Text
• End If
• lblTopics.Text strResult

87
Binding CheckBoxLists to HashTables (Page 1)

• Items are added using a key and value pair
• Declare using keyword Dim, HashTable name,
  keyword New, and Hash(n) as type (n is table
  size)
• Add method adds items to the HashTable.
• Use the key to retrieve the value for a
  particular item
• You must specify the key and value
• DataValueField is used to create the value
• DataTextField is used to create the text
  displayed

88
Binding CheckBoxLists to HashTables (Page 2)

• Add a value to a HashTable (key, value)
• Populate the CheckBoxList and bind data to
  control
• Notice that the key or value may be displayed in
  this example, the value isdisplayed
• If Not Page.IsPostBack Then
• Dim HS1 As New HashTable(5)
• HS1.Add(5, "Sports in Ireland")
• CBL.DataSource HS1
• CBL.DataTextField "Value"
• CBL.DataValueField "Key"
• CBL.DataBind()
• End If

89
Binding CheckBoxLists to HashTables (Page 3)

• Loop through each control in the list and read
  values using the Boolean Selected property
• If CBL.SelectedIndex gt -1 Then
• strResult _
• "You selected the following
  categoriesltbr /gt"
• Dim i As Integer
• For i 0 To CBL.Items.Count - 1
• If CBL.Items(i).Selected Then
• strResult CBL.Items(i).Text "ltbr
  /gt"
• End If
• Next
• Else
• strResult "You did not select a category."
• End If
• lblTopics.Text strResult

90
ASPRadioButtonList.aspx
91
ASPDBCheckboxList.aspx
92
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