ControlEventArgs Classe

Definizione

Spazio dei nomi:

System.Windows.Forms

Assembly:

System.Windows.Forms.dll

Origine:

ControlEventArgs.cs

Fornisce i dati per gli eventi ControlAdded e ControlRemoved.

C#

public class ControlEventArgs : EventArgs

Ereditarietà

Object

EventArgs

ControlEventArgs

Esempio

Nell'esempio di codice seguente viene illustrato l'uso degli ControlAdded eventi e ControlRemoved . L'esempio richiede l'aggiunta di due Button controlli al form e la connessione ai metodi di gestione degli addControl_Click eventi e removeControl_Click .

C#

// This example demonstrates the use of the ControlAdded and
// ControlRemoved events. This example assumes that two Button controls
// are added to the form and connected to the addControl_Click and
// removeControl_Click event-handler methods.
private void Form1_Load(object sender, System.EventArgs e)
{
    // Connect the ControlRemoved and ControlAdded event handlers
    // to the event-handler methods.
    // ControlRemoved and ControlAdded are not available at design time.
    this.ControlRemoved += new System.Windows.Forms.ControlEventHandler(this.Control_Removed);
    this.ControlAdded += new System.Windows.Forms.ControlEventHandler(this.Control_Added);
}

private void Control_Added(object sender, System.Windows.Forms.ControlEventArgs e)
{
    MessageBox.Show("The control named " + e.Control.Name + " has been added to the form.");
}

private void Control_Removed(object sender, System.Windows.Forms.ControlEventArgs e)
{
    MessageBox.Show("The control named " + e.Control.Name + " has been removed from the form.");
}

// Click event handler for a Button control. Adds a TextBox to the form.
private void addControl_Click(object sender, System.EventArgs e)
{
    // Create a new TextBox control and add it to the form.
    TextBox textBox1 = new TextBox();
    textBox1.Size = new Size(100,10);
    textBox1.Location = new Point(10,10);
    // Name the control in order to remove it later. The name must be specified
    // if a control is added at run time.
    textBox1.Name = "textBox1";

    // Add the control to the form's control collection.
    this.Controls.Add(textBox1);
}

// Click event handler for a Button control.
// Removes the previously added TextBox from the form.
private void removeControl_Click(object sender, System.EventArgs e)
{
    // Loop through all controls in the form's control collection.
    foreach (Control tempCtrl in this.Controls)
    {
        // Determine whether the control is textBox1,
        // and if it is, remove it.
        if (tempCtrl.Name == "textBox1")
        {
            this.Controls.Remove(tempCtrl);
        }
    }
}

Commenti

Per ulteriori informazioni sulla gestione degli eventi, consultare gestione e generazione di eventi.

Costruttori

ControlEventArgs(Control)

Inizializza una nuova istanza della classe ControlEventArgs per il controllo specificato.

Proprietà

Control

Ottiene l'oggetto controllo usato da questo evento.

Si applica a

Vedi anche

• ControlEventHandler
• ControlAdded
• ControlRemoved