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Stored procedures
The TriState property is used to:
  • Determine if a check box option supports 3 states (checked, unchecked or undefined) or 2 states (checked or unchecked).
  • Determine if the check boxes of a TreeView control support 3 states (checked, unchecked or undefined) or 2 states (checked or unchecked)
  • Change the type of an option in a check box: option with 3 states or with 2 states.
Remark: If the option supports the three states, it can take for value:
  • 0: the option is unchecked
  • 1: the option is checked
  • -1: the option is undefined (grayed)
At runtime, if the option supports three states, a first click performed on an unchecked option will check it and a second click will give it an unspecified value.
Caution: A WLanguage error occurs if an option that supports 2 states takes -1 for value. Similarly, a WLanguage error occurs if a 3-state option initialized to -1 is changed into a 2-state option.
// Defines an unspecified option
CBOX_CheckBox1[1].TriState = True
CBOX_CheckBox1[1] = -1

Determining if an element supports three states Hide the details

Result> = <Element name>.TriState
<Result>: Boolean
  • True if the option supports three states,
  • False otherwise.
<Control used>: Control name
Name of the control to be used:
  • Option of the Check Box control. The following syntax must be used: <Name of Check Box control>[<Option number>].
  • TreeView control.

Managing the three states of an option in a Check Box control Hide the details

Check Box control>[<Option number>].TriState = <Management mode
<Check Box control>: Control name
Name of Check Box control to use.
<Option number>: Integer
Number of the option to use.
<Management mode>: Boolean
  • True to manage the three states,
  • False otherwise.
The TriState property applies only to:
  • the options of a Check Box control.
  • the TreeView controls (in read-only).
Minimum version required
  • Version 14
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Last update: 07/03/2023

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