extender callback

How did you do the extension? Did you derive from ListView? Did you derive from UserControl and encapsulated the ListView?
If you did one of those options then any event you add to your control should be visible in the Designer.

Still can't work it out. If I set delegate as an extender prop it is greyed in IDE.
And events don't show in the component.

I think you've lost me. At the moment, everything works. However I have to add the delegate code by hand instead of using the designer.this is not very good because the user of the extender component will see all these properties in the designer but it will not be clear that they need to add another line in code to add the delegate.

I have extended the list into accept drop files. When a group of files are dropped, I want to fire off an event for each individual file.

Since I'm only extending the list view, the documentation says that it is better to d an extender rather than to derive from list view. So I have set up all the properties, except that there is no way to add new events with an extender that I can find.

here's an example:

using System;
using System.Windows.Forms;
using System.ComponentModel;
using System.Collections.Generic;
using System.Drawing;

namespace WindowsApplication1 {
public delegate void ListViewClickedHandler(object sender, ListViewClickedEventArgs e);
public class ListViewClickedEventArgs : EventArgs {
int column = -1;
public int Column{ get { return column; } }
public ListViewClickedEventArgs(int col) { column = col; }
}
[ProvideProperty("ListViewClickFeedback", typeof(ListView))]
public class MyExtender : Component, IExtenderProvider {
Dictionary<ListView, bool> listviews = new Dictionary<ListView, bool>();

ColumnClickEventHandler extendedClicked;
public event ListViewClickedHandler ListViewClick;
protected virtual void OnListViewClick(ListViewClickedEventArgs e) {
if(ListViewClick != null) ListViewClick(this, e);
}
public MyExtender() {
extendedClicked = new ColumnClickEventHandler(lv_Click);
}
public MyExtender(IContainer parent) : this() { parent.Add(this); }
public bool CanExtend(object extendee) {
return extendee is ListView;
}
public bool GetListViewClickFeedback(ListView lv) {
if(listviews.ContainsKey(lv)) {
return listviews[lv];
}
return false;
}
public void SetListViewClickFeedback(ListView lv, bool implement) {
if(!listviews.ContainsKey(lv)) {
listviews.Add(lv, implement);
}
if(implement) {
lv.ColumnClick += extendedClicked;
listviews[lv] = true;
} else {
lv.ColumnClick -= extendedClicked;
listviews[lv] = false;
}
}
void lv_Click(object sender, ColumnClickEventArgs e) {
OnListViewClick(new ListViewClickedEventArgs(e.Column));
}
}
}

now when you drag the extender on the form, you need to wire up the ListViewClick in the form (this will be sent when you click), I suppose you could implicitly set this up in the SetListViewClickFeedback method as well using one of the designer services, but this is just a quick sample.

not sure if this helps, but hopefully it gets you in the right direction.

I'm sure there is, I've never tried having an extender that provided an event to in the property grid of the designed object though.