Control.BackColorChanged Control.BackColorChanged Control.BackColorChanged Control.BackColorChanged Event

Définition

Se produit quand la valeur de la propriété BackColor change.Occurs when the value of the BackColor property changes.

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

Exemples

L’exemple de code suivant est un gestionnaire d’événements qui est exécuté Text lorsque la valeur de la propriété change.The following code example is an event handler that is executed when the Text property value changes. La Control classe a plusieurs méthodes avec le modèle de nom PropertyName Changed qui sont déclenchées lorsque la valeur PropertyName correspondante est modifiée (PropertyName représente le nom de la propriété correspondante).The Control class has several methods with the name pattern PropertyNameChanged that are raised when the corresponding PropertyName value changes (PropertyName represents the name of the corresponding property).

L’exemple de code suivant modifie ForeColor le d' TextBox un qui affiche les données monétaires.The following code example changes the ForeColor of a TextBox displaying currency data. L’exemple convertit le texte en nombre décimal et modifie le ForeColor en Color.Red si le Color.Black nombre est négatif et si le nombre est positif.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. Cet exemple nécessite que vous disposiez Form d’un qui TextBoxcontient un.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 

Remarques

Cet événement est déclenché si la BackColor propriété est modifiée par une modification de programmation ou une interaction utilisateur.This event is raised if the BackColor property is changed by either a programmatic modification or user interaction.

Pour plus d'informations sur la gestion des événements, voir gestion et déclenchement d’événements.For more information about handling events, see Handling and Raising Events.

S’applique à

Voir aussi