MaskedTextBox.RejectInputOnFirstFailure MaskedTextBox.RejectInputOnFirstFailure MaskedTextBox.RejectInputOnFirstFailure MaskedTextBox.RejectInputOnFirstFailure Property


Gets or sets a value indicating whether the parsing of user input should stop after the first invalid character is reached.

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

Property Value

true if processing of the input string should be terminated at the first parsing error; otherwise, false if processing should ignore all errors. The default is false.


Sometimes the user will enter several characters into a MaskedTextBox in a single input operation, typically by copying and pasting a string. If the entire string only contains valid characters, according to their paste position in the input mask, then the entire operation will succeed. However, when a parsing error occurs, the behavior of MaskedTextBox depends on the value of RejectInputOnFirstFailure, as follows:

  • If this property is true, then processing of the input string stops at the invalid character. All subsequent characters are ignored. A single MaskInputRejected event is raised.

  • If this property is false, then the invalid character is rejected, but parsing continues with the next character in the input string. A MaskInputRejected event is raised for every invalid character in the input string.

The ResetOnPrompt, ResetOnSpace and SkipLiterals properties can also influence the interpretation of the user input.

If the IsOverwriteMode property is false, then any characters already in the input mask to the right of the insertion point will be displaced by the accepted number of characters. This shifting may cause additional parsing errors.

A pasting operation can be mimicked programmatically by setting the SelectedText property.

Applies to

See also