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Control.EnabledChanged Event

Occurs when the Enabled property value has changed.

[Visual Basic]
Public Event EnabledChanged As EventHandler
[C#]
public event EventHandler EnabledChanged;
[C++]
public: __event EventHandler* EnabledChanged;

[JScript] In JScript, you can handle the events defined by a class, but you cannot define your own.

Event Data

The event handler receives an argument of type EventArgs.

Remarks

This event is raised if the Enabled property is changed by either a programmatic modification or user interaction.

For more information about handling events, see Consuming Events.

Example

[Visual Basic, C#, C++] The example below is an event handling method that is executed when the Text property value changes. The Control class has several methods with the name pattern PropertyName Changed that are raised when the corresponding PropertyName value changes(PropertyName represents the name of the corresponding property).

[Visual Basic, C#, C++] The following example changes the ForeColor of a TextBox displaying currency data. 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. This example assumes you have a Form that contains a TextBox.

[Visual Basic] 
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 

[C#] 
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;
   }
}

[C++] 
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;
        }
    }

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

See Also

Control Class | Control Members | System.Windows.Forms Namespace | OnEnabledChanged | Enabled

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