Compartilhar via


Como: Detectar quando o texto em uma TextBox foi alterado

This example shows one way to use the TextChanged event to execute a method whenever the text in a TextBox control has changed.

In the code-behind class for the XAML that contains the TextBox control that you want to monitor for changes, insert a method to call whenever the TextChanged event fires. This method must have a signature that matches what is expected by the TextChangedEventHandler delegate.

The event handler is called whenever the contents of the TextBox control are changed, either by a user or programmatically.

Note: Este evento é acionado quando o TextBox controle é criado e inicialmente preenchida com texto.

Exemplo

In the Extensible Application Markup Language (XAML) that defines your TextBox control, specify the TextChanged attribute with a value that matches the event handler method name.

<TextBox  TextChanged="textChangedEventHandler">
  Here is the initial text in my TextBox.  Each time the contents of this TextBox are changed, 
  the TextChanged event  fires and textChangedEventHandler is called.
</TextBox>

In the code-behind class for the XAML that contains the TextBox control that you want to monitor for changes, insert a method to call whenever the TextChanged event fires. This method must have a signature that matches what is expected by the TextChangedEventHandler delegate.

' TextChangedEventHandler delegate method.
Private Sub textChangedEventHandler(ByVal sender As Object, ByVal args As TextChangedEventArgs)
    ' Omitted Code: Insert code that does something whenever
    ' the text changes...
End Sub
// TextChangedEventHandler delegate method.
private void textChangedEventHandler(object sender, TextChangedEventArgs args)
{    
    // Omitted Code: Insert code that does something whenever
    // the text changes...
} // end textChangedEventHandler

The event handler is called whenever the contents of the TextBox control are changed, either by a user or programmatically.

Note: Este evento é acionado quando o TextBox controle é criado e inicialmente preenchida com texto.

Comments

Consulte também

Referência

TextChangedEventArgs

Conceitos

Visão geral sobre TextBox

Visão geral de RichTextBox