Control.BackgroundImageChanged Control.BackgroundImageChanged Control.BackgroundImageChanged Control.BackgroundImageChanged Event

定義

BackgroundImage プロパティの値が変更された場合に発生します。Occurs when the value of the BackgroundImage property changes.

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

次のコード例は、イベント ハンドラーを実行すると実行、Textプロパティ値が変更されます。The following code example is an event handler that is executed when the Text property value changes. Controlクラスがいくつかのメソッド名のパターンを持つPropertyName Changedにある場合に発生します、対応するPropertyName値の変更 (PropertyName対応するプロパティの名前を表します)。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).

次のコード例の変更、ForeColorTextBox通貨データを表示します。The following code example changes the ForeColor of a TextBox displaying currency data. 例では、文字列に変換する 10 進数と変更、ForeColorColor.Red数が負の値とするColor.Black数が正の場合。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. この例が必要です、Formを格納している、TextBoxします。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

場合、このイベントが発生した、BackgroundImageプログラムの変更またはユーザーの操作のいずれかによってプロパティを変更します。This event is raised if the BackgroundImage property is changed by either a programmatic modification or user 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.

適用対象

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