Re: ASP.NET C# Custom Control with Postback. - C# Discussion Boards

14-Aug-13 3:29

Hi All,

First time posting here, long time programmer..

So, I have a need for custom controls that I am using to dynamically render a list with call backs..

So, far I had no problem doing simple inherited based controls and hooking their callbacks...
IE CusControl : TextBox...
Then its fairly easy to hook the TextChanged event and add the controls a dynamic list and catch the post backs.

Now, the hard part is when I am no longer inheriting the TextBox base control.. but instead I want to create my own control (combo of many controls) and expose my own events to the page that contains my custom control.

For example..
I have a class, and inside the class I create my own controls.

example of the idea..

public class CusParamTextBox : BaseParam
{
    public TextBox ParamTxtBox;

    protected override void OnInit(EventArgs e)
    {
        base.OnInit(e);

        CreateCustomChildControls();
    }

    private void CreateCustomChildControls()
    {
        ParamTxtBox = new TextBox();
        ParamTxtBox.AutoPostBack = true;
        ParamTxtBox.TextChanged += new EventHandler(ParamTxtBox_TextChanged);

        base.Controls.Add(ParamTxtBox);
    }

    public void ParamTxtBox_TextChanged(object sender, EventArgs e)
    {
        TextBox cuscontrol = (TextBox)sender;
        ParamTxtBox.Text = "fired!";
        //this works.. so maybe it could be used to fire the local update event that then
        //could be exposed outside of the class.
    }

 //need to add some sort of event code for update event to expose outside of local class...
 //example ExposedUpdate()
}

Ok, so now I want to expose another event ExposedUpdate() outside of this class..
kind of like a universal update event that I want to be able to hook to the page that loads this control.

So.. inside my ASP.NET Page that contains the custom control I want to hook my own event somehow.. something like this...

//example of adding the event..

// protected override void OnInit(EventArgs e)
CusParamTextBox tmpctrlx = new CusParamTextBox();
tmpctrlx.ExposedUpdate() += new EventHandler(this.Update);

    protected void UpdateText(object sender, EventArgs e)
    {
        CusParamTextBox cuscontrol = (CusParamTextBox)sender;
        DosomethingOnPage(cuscontrol.name,cusontrol.value);
        upMain.Update();
    }

The idea would be, that the local event fires off on TextChanged then fires off the other ExposedEvent that would then be hooked into the main page to fire off more code on the main page.

Any idea or am i off the rocker and there is a better way to do this ?

OriginalGriff14-Aug-13 3:41

OriginalGriff

14-Aug-13 3:41

In future, please edit you existing question to provide info instead of creating a new one... Sigh | :sigh:

This message is manufactured from fully recyclable noughts and ones. To recycle this message, please separate into two tidy piles, and take them to your nearest local recycling centre.
Please note that in some areas noughts are always replaced with zeros by law, and many facilities cannot recycle zeroes - in this case, please bury them in your back garden and water frequently.

Richard MacCutchan14-Aug-13 3:43

Richard MacCutchan

14-Aug-13 3:43

I think between you, me and Pete, the point has been made. Smile | :)

Use the best guess

Richard MacCutchan14-Aug-13 3:42

Richard MacCutchan

14-Aug-13 3:42

He said "Edit", not Repost. For future reference, there is an Edit link at the bottom of each of your messages.

Use the best guess

Forbiddenx14-Aug-13 3:51

14-Aug-13 3:51

The site let me post twice during the process of writing a single post.

There was no confirm, and when I hit a hotkey and my work posted instantly..
Then I clicked back and it let me edit the text I was working on and then when I clicked post again it created a new post and posted again instantly.

Ultimately the problem is both user error on mypart and also software error on the forums part.
I am new, so I did not realize what just happened.. and the software did not detect that I posted twice from the same exact page...... I quick guid check or confirm could of taken place to prevent me from double posting.. And I could of stopped it if I realized it.

So, I apologize for my mistake, but I cant take all the credit!

Richard MacCutchan14-Aug-13 4:29

Richard MacCutchan

14-Aug-13 4:29

Thank you, I have posted a note at http://www.codeproject.com/Messages/4636599/Dulicate-posts.aspx[^], so the site administrators can investigate.

Use the best guess

Chris Maunder14-Aug-13 4:40

Chris Maunder

14-Aug-13 4:40

Member 4632726 wrote:
Then I clicked back and it let me edit the text I was working on and

If you had hit "Post Message" without editing, our system would have rejected the duplicate post. As it stands, you edited the text and hit send so our system thinks you simply posted a new, different message.

When you posted the original message you would have seen, just under your message, links to edit or delete your message.

We will be making changes that will make it even harder to repost accidentally.

cheers,
Chris Maunder

The Code Project | Co-founder
Microsoft C++ MVP

Richard Deeming14-Aug-13 3:47

14-Aug-13 3:47

So you just want to expose an event from your custom control?

public class CusParamTextBox : BaseParam
{
   public event EventHandler ExposedUpdate;
   
   protected virtual void OnExposedUpdate(EventArgs e)
   {
      var handler = ExposedUpdate;
      if (handler != null) handler(this, e);
   }
   
   ...
   
   private void ParamTxtBox_TextChanged(object sender, EventArgs e)
   {
      ...
      OnExposedUpdate(e);
   }
}

...

var tmpctrlx = new CusParamTextBox();
tmpctrlx.ExposedUpdate += Update;

...

protected void Update(object sender, EventArgs e)
{
   var cuscontrol = (CusParamTextBox)sender;
   DoSomethingOnPage(cuscontrol.name, cuscontrol.value);
   upMain.Update();
}

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

modified 14-Aug-13 10:02am.

Forbiddenx14-Aug-13 3:57

14-Aug-13 3:57

Yes, I want to expose a event that I can hook too.
So, I can tell it to fire in the local control... but pretty much do nothing locally... but then hook it to a page event that will do the heavy lifting.

Richard Deeming14-Aug-13 4:01

14-Aug-13 4:01

So, pretty much exactly the example I posted then? Smile | :)

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Forbiddenx14-Aug-13 5:18

14-Aug-13 5:18

Yes, Thank you so much!

That is working like a charm!

Forbiddenx14-Aug-13 7:35

14-Aug-13 7:35

Ok, I do have a new problem now..

It seems when I put this code into my update panel...
It continues to do a full post back all the time...

Any idea how how to solve this any one ?
Thanks!

Richard Deeming14-Aug-13 7:55

14-Aug-13 7:55

Have you added an AsyncPostBackTrigger[^] for the control?

ASP.NET

<asp:UpdatePanel runat="server" UpdateMode="Conditional">
  <ContentTemplate>
     <uc:CusParamTextBox ID="CusParamTextBox1" runat="server" OnExposedUpdate="Update" />
  </ContentTemplate>
  <Triggers>
    <asp:AsyncPostBackTrigger ControlID="CusParamTextBox1" EventName="ExposedUpdate" />
  </Triggers>
</asp:UpdatePanel>

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Forbiddenx14-Aug-13 8:03

14-Aug-13 8:03

I did try something like that, but a little different because I am adding the controls dynamically to a existing update panel.

I did try but with no luck..

SQL

CusParamTextBox tmpctrlx = new CusParamTextBox();
tmpctrlx.ExposedUpdate += new EventHandler(UpdateText);
ScriptManager1.RegisterAsyncPostBackControl(tmpctrlx);
CusParamControls.Controls.Add(tmpctrlx);

and on the page that contains the dyn control

<asp:UpdatePanel runat="server" ID="upMain" Visible="true" ChildrenAsTriggers="true" UpdateMode="Conditional">
    <ContentTemplate>
        <asp:Panel runat="server" ID="CusParamControls"></asp:Panel>
    </ContentTemplate>
</asp:UpdatePanel>

Richard Deeming14-Aug-13 8:14

14-Aug-13 8:14

Sorry, I'm not overly familiar with the UpdatePanel. You might be better off posting this new issue in its own thread.

NB: It would be better to post the question in the ASP.NET forum[^].

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

modified 14-Aug-13 14:30pm.

Forbiddenx16-Aug-13 7:59

ASP.NET C# Custom Control with Postback.

16-Aug-13 7:59

Hi Rich,

Its ok, I manged to figure it out..
I wanted to add the solution to the post too so other may do the same.

Right after your add your control, and then your event via the init...
If you want to put your control inside a update panel and stop a full page post back then you must register your control with the parent page and do it inside the actually control code itself... outside dont seem to work via the main page containing the control.

protected override void OnInit(EventArgs e)
{
base.OnInit(e);

ScriptManager script = ScriptManager.GetCurrent(Page);
TxtParamValue = new TextBox();
TxtParamValue.TextChanged += new EventHandler(TxtParamValue_TextChanged);
if (script != null) { script.RegisterAsyncPostBackControl(TxtParamValue);}
base.Controls.Add(TxtParamValue);
}

Thanks, and enjoy all!

Forbiddenx14-Aug-13 3:04

14-Aug-13 3:04

Pete O'Hanlon14-Aug-13 3:12

Pete O'Hanlon

14-Aug-13 3:12

Hi, you might want to edit your post. Your post finishes at "Now, the hard part is" - and we can't guess what the hard part is.

Chill _Maxxx_

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

Pete O'Hanlon14-Aug-13 3:41

Pete O'Hanlon

14-Aug-13 3:41

For future reference. If you need to update a post, don't create a new one, simply hit the edit button and fix your original post.

Chill _Maxxx_

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

Forbiddenx14-Aug-13 3:44

14-Aug-13 3:44

I actually double posted by accident..

I guess I hit the wrong hotkey and it posed it.. then I clicked the back button and edit the post not realizing it actually posted it.

please refer too the complete post below and feel free to delete this one.

http://www.codeproject.com/Messages/4636495/ASP-NET-Csharp-Custom-Control-with-Postback.aspx[^]