Occurs when the user's input or assigned character does not match the corresponding format element of the input mask.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
MaskedTextBox class.is the default event for the
An input character does not match the corresponding format element. For example, the user enters an alphabetic character when a digit is required. This is probably the most common reason why this event is raised.
The user is trying to input extraneous characters beyond the end of the mask either because the mask has already been filled or the current caret position has been moved to the very end of the displayed input mask string.
A paste operation either inserts a character that does not match its associated format element, or if the IsOverwriteMode property is false, it shifts existing characters into new positions where they do not match their format elements.
A cut operation shifts existing characters to the left, and one or more characters do not match their newly associated format elements.
An assignment was made to the Text property and the assigned string caused one or more mask violations.
If a string was assigned to the control that causes MaskedTextBox.to occur, no part of the string will appear in
The default handling for BeepOnError property is set to true. This event is often handled to implement custom error handling, for example, to move to the next user input control if the mask is full, or to display a custom error dialog box or ToolTip if the input character is invalid.will play a beep sound if the
The following code example demonstrates the use of this member. In the example, an event handler reports on the occurrence of the MessageBox::Show with Console::WriteLine or appending the message to a multiline TextBox.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
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 event.
Available since 2.0