Επεξεργασία

Κοινή χρήση μέσω

TypeValidationEventArgs.Cancel Property

  • Reference

Definition

Namespace:
System.Windows.Forms
Assembly:
System.Windows.Forms.dll
Source:
TypeValidationEventArgs.cs
Source:
TypeValidationEventArgs.cs
Source:
TypeValidationEventArgs.cs

Gets or sets a value indicating whether the event should be canceled.

public:
 property bool Cancel { bool get(); void set(bool value); };
public bool Cancel { get; set; }
member this.Cancel : bool with get, set
Public Property Cancel As Boolean

Property Value

Boolean

true if the event should be canceled and focus retained by the MaskedTextBox control; otherwise, false to continue validation processing.

Examples

The following code example demonstrates the use of this member. In the example, an event handler reports on the occurrence of the MaskedTextBox.TypeValidationCompleted 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 MaskedTextBox named MaskedTextBox1. Then ensure that the event handler is associated with the MaskedTextBox.TypeValidationCompleted event.

private void MaskedTextBox1_TypeValidationCompleted(Object sender, TypeValidationEventArgs e) {

System.Text.StringBuilder messageBoxCS = new System.Text.StringBuilder();
messageBoxCS.AppendFormat("{0} = {1}", "Cancel", e.Cancel );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "IsValidInput", e.IsValidInput );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "Message", e.Message );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "ReturnValue", e.ReturnValue );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "ValidatingType", e.ValidatingType );
messageBoxCS.AppendLine();
MessageBox.Show(messageBoxCS.ToString(), "TypeValidationCompleted Event" );
}

Private Sub MaskedTextBox1_TypeValidationCompleted(sender as Object, e as TypeValidationEventArgs) _ 
     Handles MaskedTextBox1.TypeValidationCompleted

    Dim messageBoxVB as New System.Text.StringBuilder()
    messageBoxVB.AppendFormat("{0} = {1}", "Cancel", e.Cancel)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "IsValidInput", e.IsValidInput)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "Message", e.Message)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "ReturnValue", e.ReturnValue)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "ValidatingType", e.ValidatingType)
    messageBoxVB.AppendLine()
    MessageBox.Show(messageBoxVB.ToString(),"TypeValidationCompleted Event")

End Sub

Remarks

The TypeValidationCompleted event occurs just before the Validating event.

Setting the Cancel property to true in the TypeValidationCompleted event handler will cancel the event, causing the MaskedTextBox control to retain focus, unless the subsequent Validating event sets its version of the CancelEventArgs.Cancel property to false.

Applies to

See also