Control.ForeColorChanged イベント
定義
public:
event EventHandler ^ ForeColorChanged;
public event EventHandler ForeColorChanged;
member this.ForeColorChanged : EventHandler
Public Custom Event ForeColorChanged As EventHandler
イベントの種類
例
次のコード例は、プロパティ値が変更されたときに実行されるイベントハンドラーです Text 。The following code example is an event handler that is executed when the Text property value changes. Controlクラスには、対応する propertyname 値が変更されたときに発生する名前パターンPropertyNameを持ついくつかのメソッドがあり Changed
ます (propertynameは対応するプロパティの名前を表します)。 PropertyNameThe 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).
次のコード例では、 ForeColor 表示通貨データのを変更し TextBox ます。The following code example changes the ForeColor of a TextBox displaying currency data. この例では、テキストを10進数に変換し、数値が負の場合はに、 ForeColor 数値が正の場合はに変更し Color.Red Color.Black ます。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. この例では、を含むが必要です Form 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
注釈
このイベントは、 ForeColor プロパティがプログラムの変更または対話によって変更された場合に発生します。This event is raised if the ForeColor property is changed by either a programmatic modification or through interaction.
イベントの処理の詳細については、「処理とイベントの発生」を参照してください。For more information about handling events, see Handling and Raising Events.