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TabControl.Deselecting Event

Definition

Occurs before a tab is deselected, enabling a handler to cancel the tab change.

public:
 event System::Windows::Forms::TabControlCancelEventHandler ^ Deselecting;
public event System.Windows.Forms.TabControlCancelEventHandler Deselecting;
public event System.Windows.Forms.TabControlCancelEventHandler? Deselecting;
member this.Deselecting : System.Windows.Forms.TabControlCancelEventHandler 
Public Custom Event Deselecting As TabControlCancelEventHandler 

Event Type

Examples

The following code example demonstrates the use of this member. In the example, an event handler reports on the occurrence of the Deselecting event. This report helps you to learn when the event occurs and can assist you in debugging. To report on multiple events or on events that occur frequently, consider replacing MessageBox.Show with Console.WriteLine or appending the message to a multiline TextBox.

To run the example code, paste it into a project that contains an instance of type TabControl named TabControl1. Then ensure that the event handler is associated with the Deselecting event.

private void TabControl1_Deselecting(Object sender, TabControlCancelEventArgs e) {

System.Text.StringBuilder messageBoxCS = new System.Text.StringBuilder();
messageBoxCS.AppendFormat("{0} = {1}", "TabPage", e.TabPage );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "TabPageIndex", e.TabPageIndex );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "Action", e.Action );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "Cancel", e.Cancel );
messageBoxCS.AppendLine();
MessageBox.Show(messageBoxCS.ToString(), "Deselecting Event" );
}
Private Sub TabControl1_Deselecting(sender as Object, e as TabControlCancelEventArgs) _ 
     Handles TabControl1.Deselecting

    Dim messageBoxVB as New System.Text.StringBuilder()
    messageBoxVB.AppendFormat("{0} = {1}", "TabPage", e.TabPage)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "TabPageIndex", e.TabPageIndex)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "Action", e.Action)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "Cancel", e.Cancel)
    messageBoxVB.AppendLine()
    MessageBox.Show(messageBoxVB.ToString(),"Deselecting Event")

End Sub

Remarks

When the current tab changes in a TabControl, the following events occur in the following order.

These events let you perform tasks such as canceling a tab change if a TabPage is in an invalid state or updating the state of a newly displayed TabPage.

The current tab changes when the user clicks a tab, when you call the DeselectTab or SelectTab method, or when you change the value of the SelectedIndex or SelectedTab property.

Applies to

See also