CheckedListBox.CheckOnClick Property

Gets or sets a value indicating whether the check box should be toggled when an item is selected.

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

public bool CheckOnClick { get; set; }
/** @property */
public boolean get_CheckOnClick ()

/** @property */
public void set_CheckOnClick (boolean value)

public function get CheckOnClick () : boolean

public function set CheckOnClick (value : boolean)

Not applicable.

Property Value

true if the check mark is applied immediately; otherwise, false. The default is false.

CheckOnClick indicates whether the check box should be toggled whenever an item is selected. The default behavior is to change the selection on the first click, and then have the user click again to apply the check mark. In some instances, however, you might prefer have the item checked as soon as it is clicked.

The following code example demonstrates initializing a CheckedListBox control by setting the CheckOnClick, SelectionMode, and ThreeDCheckBoxes properties. The example populates the CheckedListBox with controls and sets the DisplayMember to the Control.Name property of the control.

To run the example, paste the following code in a form containing a CheckedListBox named CheckedListBox1 and call the InitializeCheckListBox method from the form's constructor or Load method.

// This method initializes CheckedListBox1 with a list of all 
// the controls on the form. It sets the selection mode
// to single selection and allows selection with a single click.
// It adds itself to the list before adding itself to the form.

internal System.Windows.Forms.CheckedListBox CheckedListBox1;

private void InitializeCheckedListBox()
    this.CheckedListBox1 = new CheckedListBox();
    this.CheckedListBox1.Location = new System.Drawing.Point(40, 90);
    this.CheckedListBox1.CheckOnClick = true;
    this.CheckedListBox1.Name = "CheckedListBox1";
    this.CheckedListBox1.Size = new System.Drawing.Size(120, 94);
    this.CheckedListBox1.TabIndex = 1;
    this.CheckedListBox1.SelectionMode = SelectionMode.One;
    this.CheckedListBox1.ThreeDCheckBoxes = true;

    foreach ( Control aControl in this.Controls )
        this.CheckedListBox1.Items.Add(aControl, false);

    this.CheckedListBox1.DisplayMember = "Name";

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

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