Control.TextChanged Control.TextChanged Control.TextChanged Control.TextChanged Event

Definizione

Si verifica quando il valore della proprietà Text cambia.Occurs when the Text property value changes.

public:
 event EventHandler ^ TextChanged;
public event EventHandler TextChanged;
member this.TextChanged : EventHandler 
Public Custom Event TextChanged As EventHandler 

Esempi

Il codice seguente esempio modifica il ForeColor di un TextBox la visualizzazione dei dati di valuta.The following code example changes the ForeColor of a TextBox displaying currency data. L'esempio converte il testo in un numero decimale e delle modifiche la ForeColor al Color.Red se il numero è negativo e su Color.Black se il numero è positivo.The example converts the text to a decimal number and changes the ForeColor to Color.Red if the number is negative and to Color.Black if the number is positive. In questo esempio è necessario disporre una Form che contiene un TextBox.This example requires that you have a Form that contains a TextBox.

private:
   void currencyTextBox_TextChanged( Object^ /*sender*/, EventArgs^ /*e*/ )
   {
      try
      {
         // Convert the text to a Double and determine if it is a negative number.
         if ( Double::Parse( currencyTextBox->Text ) < 0 )
         {
            // If the number is negative, display it in Red.
            currencyTextBox->ForeColor = Color::Red;
         }
         else
         {
            // If the number is not negative, display it in Black.
            currencyTextBox->ForeColor = Color::Black;
         }
      }
      catch ( Exception^ ) 
      {
         // If there is an error, display the text using the system colors.
         currencyTextBox->ForeColor = SystemColors::ControlText;
      }
   }
private void currencyTextBox_TextChanged(object sender, EventArgs e)
{
   try
   {
      // Convert the text to a Double and determine if it is a negative number.
      if(double.Parse(currencyTextBox.Text) < 0)
      {
         // If the number is negative, display it in Red.
         currencyTextBox.ForeColor = Color.Red;
      }
      else
      {
         // If the number is not negative, display it in Black.
         currencyTextBox.ForeColor = Color.Black;
      }
   }
   catch
   {
      // If there is an error, display the text using the system colors.
      currencyTextBox.ForeColor = SystemColors.ControlText;
   }
}
Private Sub currencyTextBox_TextChanged(sender As Object, _ 
  e As EventArgs) Handles currencyTextBox.TextChanged
   Try
      ' Convert the text to a Double and determine if it is a negative number.
      If Double.Parse(currencyTextBox.Text) < 0 Then
         ' If the number is negative, display it in Red.
         currencyTextBox.ForeColor = Color.Red
      Else
         ' If the number is not negative, display it in Black.
         currencyTextBox.ForeColor = Color.Black
      End If
   Catch
      ' If there is an error, display the text using the system colors.
      currencyTextBox.ForeColor = SystemColors.ControlText
   End Try
End Sub 

Commenti

Questo evento viene generato se il Text proprietà viene modificata da una modifica a livello di codice o l'interazione dell'utente.This event is raised if the Text property is changed by either a programmatic modification or user interaction.

Per ulteriori informazioni sulla gestione degli eventi, consultare gestione e generazione di eventi.For more information about handling events, see Handling and Raising Events.

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