| Groups | Blog | Home |
asp.net building controls : No events are fired in child control
I have developed a custom web control that may contain any child controls.
Now I have a problem that even though I register an event handler on a child control, the event handler does not fire when it should. Do I need to handle event registrations of child controls specially? Casper
hi casper,
Your going to have to override your onBubbleEvent method for your control and take action here or bubble it up futher to the container(the page). providing a common event handler for all events fired. To differeniate btw controls and who is posting back your end users will have to supply a name to the buttons commandName property which is exposed by controls that postback and then let them use this to handle handle events in one common handler. [quoted text, click to view] "Casper Hornstrup" <msdn@csite.com> wrote in message news:O45w3Zm5DHA.2764@TK2MSFTNGP09.phx.gbl... > I have developed a custom web control that may contain any child controls. > Now I have a problem that even though I register an event handler on a child > control, > the event handler does not fire when it should. Do I need to handle event > registrations > of child controls specially? > > Casper > >
Hi Casper, Thank you for posting in the community! Based on my understanding, you are building a custom control, in which you created several child controls. Althrough you have added event handler for your child control, this event handle does not take effect. =================================================== Where do you create your child controls? Do you create your child control through override Control.CreateChildControls? Acutally, in Composite Control, if you want to hook the child controls' event, you must implement the System.Web.UI.INamingContainer interface. It will provide you the unique names in the hierarchical tree of controls. If you do not implement this interface, asp.net model will not associate the event handler well. For example, this code will work well: using System; using System.Web.UI; using System.Web.UI.WebControls; using System.ComponentModel; namespace CustomControls { public class EventBubbler : System.Web.UI.WebControls.WebControl, INamingContainer { protected override void CreateChildControls() { Button button1 = new Button(); button1.Text = "Click"; button1.Click+=new EventHandler(button1_Click); Controls.Add(button1); } private void button1_Click(object sender, EventArgs e) { this.Page.Response.Write("Child button event fires"); } } } But this will not fire your event: using System; using System.Web.UI; using System.Web.UI.WebControls; using System.ComponentModel; namespace CustomControls { public class EventBubbler : System.Web.UI.WebControls.WebControl { protected override void CreateChildControls() { Button button1 = new Button(); button1.Text = "Click"; button1.Click+=new EventHandler(button1_Click); Controls.Add(button1); } private void button1_Click(object sender, EventArgs e) { this.Page.Response.Write("Child button event fires"); } } } For more information, please refer to "Developing a Composite Control" at: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/htm l/cpcondevelopingcompositecontrols.asp ================================================================ Please apply my suggestion above and let me know if it helps resolve your problem. Thank you for your patience and cooperation. If you have any questions or concerns, please feel free to post it in the group. I am standing by to be of assistance. Have a nice day!! Best regards, Jeffrey Tan Microsoft Online Partner Support Get Secure! - www.microsoft.com/security This posting is provided "as is" with no warranties and confers no rights.
Hi Casper, Thanks for your feedback. I am glad it works. If you have any further concern, please feel free to tell me, I will work with you. Best regards, Jeffrey Tan Microsoft Online Partner Support Get Secure! - www.microsoft.com/security This posting is provided "as is" with no warranties and confers no rights.
Hi Alessandro, Yes, I also through INamingContainer is useless in the past, but not now. :-) You are welcome. Best regards, Jeffrey Tan Microsoft Online Partner Support Get Secure! - www.microsoft.com/security This posting is provided "as is" with no warranties and confers no rights.
Hi Jeffrey.
I implemented INamingContainer in the control and events now work. Thanks, Casper [quoted text, click to view] ""Jeffrey Tan[MSFT]"" <v-jetan@online.microsoft.com> wrote in message news:bxHHiov5DHA.1992@cpmsftngxa07.phx.gbl... > > Hi Casper, > > Thank you for posting in the community! > > Based on my understanding, you are building a custom control, in which you > created several child controls. Althrough you have added event handler for > your child control, this event handle does not take effect. > > =================================================== > Where do you create your child controls? Do you create your child control > through override Control.CreateChildControls? > > Acutally, in Composite Control, if you want to hook the child controls' > event, you must implement the System.Web.UI.INamingContainer interface. It > will provide you the unique names in the hierarchical tree of controls. If > you do not implement this interface, asp.net model will not associate the > event handler well. > > For example, this code will work well: > using System; > using System.Web.UI; > using System.Web.UI.WebControls; > using System.ComponentModel; > > namespace CustomControls > { > public class EventBubbler : System.Web.UI.WebControls.WebControl, > INamingContainer > { > protected override void CreateChildControls() > { > Button button1 = new Button(); > button1.Text = "Click"; > button1.Click+=new EventHandler(button1_Click); > Controls.Add(button1); > } > > private void button1_Click(object sender, EventArgs e) > { > this.Page.Response.Write("Child button event fires"); > } > } > } > > But this will not fire your event: > using System; > using System.Web.UI; > using System.Web.UI.WebControls; > using System.ComponentModel; > > namespace CustomControls > { > public class EventBubbler : System.Web.UI.WebControls.WebControl > { > protected override void CreateChildControls() > { > Button button1 = new Button(); > button1.Text = "Click"; > button1.Click+=new EventHandler(button1_Click); > Controls.Add(button1); > } > > private void button1_Click(object sender, EventArgs e) > { > this.Page.Response.Write("Child button event fires"); > } > } > } > > For more information, please refer to "Developing a Composite Control" at: > http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/htm > l/cpcondevelopingcompositecontrols.asp > > ================================================================ > Please apply my suggestion above and let me know if it helps resolve your > problem. > > Thank you for your patience and cooperation. If you have any questions or > concerns, please feel free to post it in the group. I am standing by to be > of assistance. > Have a nice day!! > > Best regards, > Jeffrey Tan > Microsoft Online Partner Support > Get Secure! - www.microsoft.com/security > This posting is provided "as is" with no warranties and confers no rights. >
hi Jeffery, thanks for pointing this out. Somehow I had always missed that
part on the docs where it says that implementing the INamingContainer interface is important also when you need to route events to its child controls. I was always under the impression that when inheriting from webControls this interface was useless the reason being that I started facing naming problems for child controls when trying to pass an explicit ID whereas to the generic uniqueID supplied by asp.net However now i see that supplying "clientID" & "_name" or me.ID & "_name" to a child controls ID is wrong. This has just fixed a bug a bug for me in my control. Thanks again ;) [quoted text, click to view] ""Jeffrey Tan[MSFT]"" <v-jetan@online.microsoft.com> wrote in message news:bxHHiov5DHA.1992@cpmsftngxa07.phx.gbl... > > Hi Casper, > > Thank you for posting in the community! > > Based on my understanding, you are building a custom control, in which you > created several child controls. Althrough you have added event handler for > your child control, this event handle does not take effect. > > =================================================== > Where do you create your child controls? Do you create your child control > through override Control.CreateChildControls? > > Acutally, in Composite Control, if you want to hook the child controls' > event, you must implement the System.Web.UI.INamingContainer interface. It > will provide you the unique names in the hierarchical tree of controls. If > you do not implement this interface, asp.net model will not associate the > event handler well. > > For example, this code will work well: > using System; > using System.Web.UI; > using System.Web.UI.WebControls; > using System.ComponentModel; > > namespace CustomControls > { > public class EventBubbler : System.Web.UI.WebControls.WebControl, > INamingContainer > { > protected override void CreateChildControls() > { > Button button1 = new Button(); > button1.Text = "Click"; > button1.Click+=new EventHandler(button1_Click); > Controls.Add(button1); > } > > private void button1_Click(object sender, EventArgs e) > { > this.Page.Response.Write("Child button event fires"); > } > } > } > > But this will not fire your event: > using System; > using System.Web.UI; > using System.Web.UI.WebControls; > using System.ComponentModel; > > namespace CustomControls > { > public class EventBubbler : System.Web.UI.WebControls.WebControl > { > protected override void CreateChildControls() > { > Button button1 = new Button(); > button1.Text = "Click"; > button1.Click+=new EventHandler(button1_Click); > Controls.Add(button1); > } > > private void button1_Click(object sender, EventArgs e) > { > this.Page.Response.Write("Child button event fires"); > } > } > } > > For more information, please refer to "Developing a Composite Control" at: > http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/htm > l/cpcondevelopingcompositecontrols.asp > > ================================================================ > Please apply my suggestion above and let me know if it helps resolve your > problem. > > Thank you for your patience and cooperation. If you have any questions or > concerns, please feel free to post it in the group. I am standing by to be > of assistance. > Have a nice day!! > > Best regards, > Jeffrey Tan > Microsoft Online Partner Support > Get Secure! - www.microsoft.com/security > This posting is provided "as is" with no warranties and confers no rights. >
Don't see what you're looking for? Try a search.
|
June 2003
July 2003
August 2003
September 2003
October 2003
November 2003
December 2003
January 2004
February 2004
March 2004
April 2004
May 2004
June 2004
July 2004
August 2004
September 2004
October 2004
November 2004
December 2004
January 2005
February 2005
March 2005
April 2005
May 2005
June 2005
July 2005
August 2005
September 2005
October 2005
November 2005
December 2005
January 2006
February 2006
March 2006
April 2006
May 2006
June 2006
July 2006
August 2006
September 2006
October 2006
November 2006
December 2006
January 2007
February 2007
March 2007
April 2007
May 2007
June 2007
July 2007
August 2007
September 2007
October 2007
November 2007
December 2007
January 2008
February 2008
March 2008
April 2008
May 2008
June 2008
| home · blog · groups | Questions? Comments? Contact the dn |