Control.BackgroundImageChanged Event
Definition
Important
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Occurs when the value of the BackgroundImage property changes.
public:
event EventHandler ^ BackgroundImageChanged;public event EventHandler BackgroundImageChanged;public event EventHandler? BackgroundImageChanged;member this.BackgroundImageChanged : EventHandler Public Custom Event BackgroundImageChanged As EventHandler Event Type
Examples
The following code example is an event handler that is executed when the Text property value changes. 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).
The following code 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 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
Remarks
This event is raised if the BackgroundImage property is changed by either a programmatic modification or user interaction.
For more information about handling events, see Handling and Raising Events.
Applies to
See also
.NET