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Captcha Control


Captcha(Completely Automated Public Turing test to tell Computers and Humans apart) control is a type of challenge response test used in computing to determine whether or not the user is human. It is a validation tool which displays some random string which the user has to type to submit the form. Captcha is like a testing input to ensure you are dealing with a human and not a robot.

Working with a Captcha control

  • Create a form as shown in Figure 1, by dragging a ‘Captcha’ control.
  • In the properties tab of Captcha control user can set various properties like type of captcha text and can set border of control (Figure 2). Captcha control is a case sensitive validation tool.
Figure 2
  • The Captcha text type feature in Captcha control Property tab allows the user to select the type of text which should appear in Captcha image (Figure 3).
Figure 3

  • Preview of a form containing captcha control is shown in Figure 4.
Figure 4
  • In order to validate a form using captcha control user should write the following rule (Figure 5). ValidateCaptcha() is used to validate the text in captcha image and returns true value if it is matching. All the actions that are to be performed after validation are written under the condition true.
Figure 5
  • And if it is not matching user can set a validation message as an indication to user that they went wrong with the captcha image (Figure 6).
Figure 6

Control Name: Captcha
Group: Validation Control

S.noProperty NameData TypeDescription
1Captcha Text TypeStringSet the type of captcha text.
2Default messageStringSets the message that is to be displayed in captcha textbox by default.
3Show Attached TextboxBooleanTo display the attached textbox along with the control.
4RemarksStringTo make a comment or observation about the control for reference.
5Show BorderBooleanTo set the border for the control.
S.noProperty Name
Data TypeDescription
6WidthStringSets the suggested width or thickness to the control.
7HeightStringSets the suggested height to the control.
8MarginStringSets the edge or outer margin to the control.
9Background ColorStringSets a brush that describes the Background color of the control.
10VisibleBooleanSets the visibility of the control while rendering.
11EnableBooleanSets the accessibility of the control during rendering.
12Column SpanStringTo merge the number of column specified.