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Control.TextChanged Event

Occurs when the Text property value changes.

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

[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 Text 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 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 | OnTextChanged | Text

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