Web Server Controls

1
Web Server Controls

• Lab4 Web Server Controls

2
ASP.Net WebForm Controls

• Most ASP.Net 3.5 Web Server controls are located
  on the Standard tab in the toolbox.
• The ASP.Net Webforms inherit from the Web Control
  class which is found in the System.Web.UI.WebContr
  ols namespace.
• Label (label1.Text)
• TextBox (TextBox1.Text)
• Image / ImageButton (imageUrl)
• Button (click)
• Dropdown List (dropdownList1.SelectedValue)
• ListBox
• Checkbox / CheckBoxList
• Radiobutton / RadioButtonList
• Calendar
• FileUpLoad
• Panel
• PlaceHolder

3
Panel Control

• The Panel control is used as a container for
  other controls. It serves several functions-
  To control the visibility of the control it
  contains- To control the appearance of the
  controls it contains- To make it easier to
  generate controls programmatically.

4
PlaceHolder Control

• The PlaceHolder Web server control holds a spot
  for you to programmatically add or remove
  controls in its place. Using PlaceHolder control
  can help dynamically build forms and customize
  the users interface.
• The PlaceHolder control doesnt produce any
  visible output without the use of other controls.

5
Using Validation Controls

• The five validation controls are
• RequiredFieldValidator Makes sure a form field
  is not left blank
• RangeValidator Makes sure a fields value falls
  between a given range
• CompareValidator Compares a fields value with
  other values or other fields values
• RegularExpressionValidator Evaluates data
  against a regular expression
• CustomValidator Evaluates data against custom
  criteria

6
Common Validation Control Properties

• ControlToValidate Name of the control to check
• ErrorMessage -- text to be displayed if invalid
• Text text to be displayed if the data is
  invalid
• Display
• Static
• Dynamic
• None
• SetFocusOnError set focus to control if invalid

7
Specialized Properties

• RequiredFieldValidator
• InitialValue invalid if control matches
  InitialValue (defaults to nothing)
• CompareValidator
• Opeartor type of comparison
• ValueToCompare value to test against
• ControlToCompare name of control to test against
• RangeValidator
• MinimumValue
• MaximumValue
• Type
• RegularExpression
• ValidationExpression format

8
Validator Examples

• Validator settings User Entry
  Result?
• RequiredField
• InitialValue
• InitialValue Enter Name
• CompareValidator
• ValueToCompare Pat Operator Equal
  Type String
• ValueToCompare Pat Operator Equal
  Type String Operator DataTypeCheck Type
  Currency

Valid?
Enter Name
Valid?
Valid?
Valid?
pat
Pat
Valid?
9
Validator Examples (cont.)

• Validator settings User Entry
  Result?
• RangeValidator
• MaximumValue20
• MinimumValue 2 Type String
• MaximumValue20
• MinimumValue 2 Type Integer
• MaximumValueThompson
• MinimumValue Fred Type String
• RegularExpressionValidator ValidationExpression
  A-Z\dA-Z\ \dA-Z\d

15
Valid?
Valid?
15
Valid?
Terry
N7A 2L3
Valid?
10
ValidationSummary Control

• To summarize the error messages from all
  validators on a Web page, in one location
• DisplayMode displays as a list (List), a
  bulleted list (BulletList), or a single paragraph
  (SingleParagraph)
• ShowSummary - shows the entire list of error
  messages from invalid controls
• ShowMessageBox - displays an additional message
  in an alert box by setting
• HeaderText - allows you to display a heading
  message

11
Extending Validation

• ValidationGroup property -- Validators and
  Buttons
• CausesValidation property any control that can
  submit a page
• Checking that validation succeeded Page--
  IsValid

12
Lab 4 Exercises