CheckBox::ThreeState Property


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Gets or sets a value indicating whether the CheckBox will allow three check states rather than two.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

property bool ThreeState {
	bool get();
	void set(bool value);

Property Value

Type: System::Boolean

true if the CheckBox is able to display three check states; otherwise, false. The default value is false.

If the ThreeState property is set to false, the CheckState property value can only be set to the Indeterminate value of System.Windows.Forms::CheckState in code and not by user interaction.

The following code example displays the values of three properties in a label. The ThreeState property alternates between true and false with alternating clicks of the control and the CheckAlign alternates between the MiddleRight and MiddleLeft values of System.Drawing::ContentAlignment. This example shows how the property values change as the ThreeState property changes and the control is checked. This code requires that a CheckBox, Label and Button have all been instantiated on a form and that the label is large enough to display three lines of text, as well as a reference to the System.Drawing namespace. This code should be called in the Click event handler of the control.

   void AdjustMyCheckBoxProperties()
      // Concatenate the property values together on three lines.
      label1->Text = String::Format( "ThreeState: {0}\nChecked: {1}\nCheckState: {2}",
         checkBox1->ThreeState, checkBox1->Checked, checkBox1->CheckState );

      // Change the ThreeState and CheckAlign properties on every other click.
      if ( !checkBox1->ThreeState )
         checkBox1->ThreeState = true;
         checkBox1->CheckAlign = ContentAlignment::MiddleRight;
         checkBox1->ThreeState = false;
         checkBox1->CheckAlign = ContentAlignment::MiddleLeft;

.NET Framework
Available since 1.1
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