Events And User Controls

Hi,

I've got a user control inheriting from System.Windows.Forms.TextBox and I've added a ListBox as a child. I would like to expose an event when the ListBox changes visibility. Any help would be greatly appreciated.

Code Snippet Follows====================================

public class TextBoxLookup : System.Windows.Forms.TextBox

{

private System.Windows.Forms.ListBox listBox1;

private void OpenListBox()

{

Control ctlParent = this.Parent;

ctlParent.Controls.Add(this.listBox1);

this.Text = "";

this.BackColor = Color.GhostWhite;

this.listBox1.Location = new System.Drawing.Point(this.Location.X, this.Location.Y + 20);

this.listBox1.Width = this.Width;

this.listBox1.BringToFront();

this.listBox1.Visible = true;

}

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Events And User Controls

Mattias Svensson

Hi Rich.

When cgraus says "expose your delegate", he means creating a public event on your class, which you raise in your event handler. This documentation should help: http://msdn.microsoft.com/library/default.asp url=/library/en-us/csref/html/vclrfEventPG.asp

Hope this helps!

Scott Nonnenberg
Vince15
Your control should have an event handler that subscribes to the list boxes 'OnVisibleChanged', then expose a delegate that is called in this event handler.
JPlenert

I've setup an event for the ListBox such as shown below but I'm vague on using a delegate to expose the event Again any help woud be greatly appreciated.

this.listBox1.VisibleChanged +=new EventHandler(listBox1_VisibleChanged);

private void listBox1_VisibleChanged(object sender, EventArgs e)

{

}
Events And User Controls

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