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TextChangedEventArgs Class

Provides data for the TextChanged event.


Namespace:  System.Windows.Controls
Assembly:  PresentationFramework (in PresentationFramework.dll)

public class TextChangedEventArgs : RoutedEventArgs

The TextChangedEventArgs type exposes the following members.

Public methodTextChangedEventArgs(RoutedEvent, UndoAction)Initializes a new instance of the TextChangedEventArgs class, using the specified event ID and undo action.
Public methodTextChangedEventArgs(RoutedEvent, UndoAction, ICollection<TextChange>)Initializes a new instance of the TextChangedEventArgs class, using the specified event ID, undo action, and text changes.

Public propertyChangesGets a collection of objects that contains information about the changes that occurred.
Public propertyHandledGets or sets a value that indicates the present state of the event handling for a routed event as it travels the route. (Inherited from RoutedEventArgs.)
Public propertyOriginalSourceGets the original reporting source as determined by pure hit testing, before any possible Source adjustment by a parent class. (Inherited from RoutedEventArgs.)
Public propertyRoutedEventGets or sets the RoutedEvent associated with this RoutedEventArgs instance. (Inherited from RoutedEventArgs.)
Public propertySourceGets or sets a reference to the object that raised the event. (Inherited from RoutedEventArgs.)
Public propertyUndoActionGets how the undo stack is caused or affected by this text change

Public methodEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodInvokeEventHandlerPerforms the proper type casting to call the type-safe TextChangedEventHandler delegate for the TextChanged event. (Overrides RoutedEventArgs.InvokeEventHandler(Delegate, Object).)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Protected methodOnSetSourceWhen overridden in a derived class, provides a notification callback entry point whenever the value of the Source property of an instance changes. (Inherited from RoutedEventArgs.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)

The following example displays the number of times the text in a TextBox changes. Below is the XAML code for the example.

<Page xmlns=""
      Here is the initial text in the textbox.  Each time the contents of this box is changed, a change counter will
      be incremented and displayed in the TextBox below.  Note that the TextChanged event is called when the TextBox
      control is initially populated with text, so the changes counter starts of at 1.
    <TextBox Name="tbCounterText">0</TextBox>


Below is the code behind for the example.

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;

namespace SDKSample

    public partial class DetectChangedTextExample : Page

        // This is a counter for the number of times the TextChanged fires
        // for the tbCountingChanges TextBox.
        private int uiChanges = 0;

        // Event handler for TextChanged Event.
        private void textChangedEventHandler(object sender, TextChangedEventArgs args)

            if (tbCounterText != null)
                tbCounterText.Text = uiChanges.ToString();


.NET Framework

Supported in: 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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