TypeValidationEventArgs Class
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TypeValidationEventArgs Class


Provides data for the TypeValidationCompleted event.

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


public class TypeValidationEventArgs : EventArgs

System_CAPS_pubmethodTypeValidationEventArgs(Type, Boolean, Object, String)

Initializes a new instance of the TypeValidationEventArgs class.


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


Gets a value indicating whether the formatted input string was successfully converted to the validating type.


Gets a text message describing the conversion process.


Gets the object that results from the conversion of the formatted input string.


Gets the type that the formatted input string is being validated against.


Determines whether the specified object is equal to the current object.(Inherited from Object.)


Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)


Serves as the default hash function. (Inherited from Object.)


Gets the Type of the current instance.(Inherited from Object.)


Creates a shallow copy of the current Object.(Inherited from Object.)


Returns a string that represents the current object.(Inherited from Object.)

The TypeValidationCompleted event occurs when a MaskedTextBox control performs optional type validation. Type validation occurs only when the MaskedTextBox.ValidatingType property is not null and a causal action occurs, such as the MaskedTextBox control losing focus. Type validation is the ability to convert the formatted input string to the type represented by the ValidatingType property. For more information about the type validation process, see the TypeValidationCompleted event.

If an event handler is implemented for TypeValidationCompleted, the handler receives a parameter of type TypeValidationEventArgs. This parameter contains information about the event, such as whether the type conversion process succeeded, the validating type, and so on.

The following code example demonstrates the use of this type. In the example, an event handler reports on the occurrence of the 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 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 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.AppendFormat("{0} = {1}", "IsValidInput", e.IsValidInput );
messageBoxCS.AppendFormat("{0} = {1}", "Message", e.Message );
messageBoxCS.AppendFormat("{0} = {1}", "ReturnValue", e.ReturnValue );
messageBoxCS.AppendFormat("{0} = {1}", "ValidatingType", e.ValidatingType );
MessageBox.Show(messageBoxCS.ToString(), "TypeValidationCompleted Event" );

.NET Framework
Available since 2.0

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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