Adding a control to a custom web control

  • Thread starter Thread starter Web Team @ Borough of Poole
  • Start date Start date
W

Web Team @ Borough of Poole

Hi All,

Can someone please explain how I go about adding a control (Say for
example a panel) to a custom web control.

I've tried this:
Protected Overrides Sub Render(ByVal output As
System.Web.UI.HtmlTextWriter)
Dim EditPanel As New System.Web.UI.webcontrols.Panel
EditPanel.Attributes.Add("contenteditable", "")
EditPanel.BorderColor = System.Drawing.Color.AliceBlue
Me.Controls.Add(EditPanel)
End Sub

The panel doesnt seem to get written to the page.

I'm trying to get to the point where my user can enter some text into
the panel, which I can then get out of the control when they click
save/update/whatever.

Thanks!

Simon.
 
I'd suggest moving that code into the Init event for the control, or
perhaps the Load event. The Render event is a bit late in the process
to be adding controls, and you'd need to call the base class Render or
RenderChildren method to get any HTML spit out.
 
This whole idea isn't going to work as easy as you want. Just by
setting the panels "ContentEditable" attribute to true will not cause
the data entered to be posted back the server. To make this work you
will need to load the content that someone is entering into the
contenteditable div into a hidden variable (using javascript) on the
page and then get the value from there. You would be better searching
and downloading a control that already does this like:

http://www.freetextbox.com
 
aa7im - I understand that adding ContentEditable is not going to write
my code for me. It simply says to the browser that the client can
change the innerHTML of the control.

I hear what you say about moving the editied HTML into a hidden
variable, which is exactly how our current ASP based editor works. I
can easily write the javascript to do this, but the hidden form field
still needs to be accessible as a server side control, so that I can
get my control to return the value of the editied text.

Scott - I'll try what you suggest, any ideas how I control where the
panel is out put to on the page?

Thanks,
Simon.
 
Scott - I'll try what you suggest, any ideas how I control where the
panel is out put to on the page?
Click to expand...


If you want to inject the panel into the page dynamically and control
the position precisely, then the best solution is to put an
<asp:PlaceHolder> control on the page.

During the Load or Init event use the code you have in the Render
method to create the Panel and add it to the PlaceHolder object's
Controls collection.

Scott Mitchell has some example in this article:
http://aspnet.4guysfromrolla.com/articles/081402-1.aspx
 
Ok...

So are trying to create a custom web control?

You can just inherit from the WebControl class

public class MyControl:WebControl
{
protected override HtmlTextWriterTag TagKey
{
get
{
return HtmlTextWriterTag.Span;
}
}

protected override void Render(HtmlTextWriter writer)
{
writer.AddAttribute("contenteditable","on");
}
}
 
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