remove all event handlers from a control
5323 ワード
The sample code below will remove all
or
or
Click
events from button1
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
button1.Click += button1_Click;
button1.Click += button1_Click2;
button2.Click += button2_Click;
}
private void button1_Click(object sender, EventArgs e)
{
MessageBox.Show("Hello");
}
private void button1_Click2(object sender, EventArgs e)
{
MessageBox.Show("World");
}
private void button2_Click(object sender, EventArgs e)
{
RemoveClickEvent(button1);
}
private void RemoveClickEvent(Button b)
{
FieldInfo f1 = typeof(Control).GetField("EventClick",
BindingFlags.Static | BindingFlags.NonPublic);
object obj = f1.GetValue(b);
PropertyInfo pi = b.GetType().GetProperty("Events",
BindingFlags.NonPublic | BindingFlags.Instance);
EventHandlerList list = (EventHandlerList)pi.GetValue(b, null);
list.RemoveHandler(obj, list[obj]);
}
}
}
or
void OnFormClosing(object sender, FormClosingEventArgs e)
{
foreach(Delegate d in FindClicked.GetInvocationList())
{
FindClicked -= (FindClickedHandler)d;
}
}
or
Directly no, in large part because you cannot simply set the event to null.
Indirectly, you could make the actual event private and create a property around it that tracks all of the delegates being added/subtracted to it.
Take the following:
List<EventHandler> delegates = new List<EventHandler>();
private event EventHandler MyRealEvent;
public event EventHandler MyEvent
{
add
{
MyRealEvent += value;
delegates.Add(value);
}
remove
{
MyRealEvent -= value;
delegates.Remove(value);
}
}
public void RemoveAllEvents()
{
foreach(EventHandler eh in delegates)
{
MyRealEvent -= eh;
}
delegates.Clear();
}