Showing posts with label populated. Show all posts
Showing posts with label populated. Show all posts

Wednesday, March 28, 2012

UpdateProgress with DropDownList Controls (or others)

I have a UpdateProgress control that works with the submit button; how do I get it to work with a dropdown list that gets populated from a web service? Thanks.

Dan

I am not sure, if i had understood your problem correctly. An UpdateProgress control is attached to an update panel. So it doesnt matter if the post back is caused by a button or a dropdownlist. Make sure you have the dropdownlist in the updatepanel for which the updateprogress is attached.

Thanks

Monday, March 26, 2012

Updating a Tree Control with Ajax

I'm new to Ajax so forgive me if this is an obvious question. I have a Tree control that's populated when a form loads. It has 4 levels of nodes. When one clicks on the lowest level (the leaves) then associated data populates controls to the right of the tree view.

There has to be the ability to delete a leaf. When this is done, might the Ajax update control be used to remove the leaf from the tree, yet keep the tree positioned in the same place?

An unrelated question: Is there an ASP.Net 2.0 web control that acts like a resizable panel similar to what's available with WinForms? This sort of thing exists on MSDN: http://msdn2.microsoft.com/en-us/library/ms229335.aspx (ie. the panel on the left)

Robert W.


Hi,rmdw

What you meant "keep the tree positioned in the same place"?

I'm sorry for that I cann't understand your question.Can you provide more information?


Suppose you had a tree that looked like this:

+ A

+ B

+ C


Now suppose you open up the "B" node to reveal this:

+ A

- B

- B1

- B2

- B3

+ C

Now suppose the user wants to delete leaf "B2". What I would like is for the tree to be redrawn (refreshed) with B2 gone but still showing the user the same portion of the tree. Obviously for such a small example it probably always will be shown but imagine there were 100 parent nodes and multiple levels.

Robert


Ha Ha, I see, you wanna keep the tree like this:

+ A

- B

- B1

- B3

+ C

after you deleted leaf "B2".

But it show you this:

+ A

+ B

+ C

because the updatepanel refreshed.

I advise you using webservice or webmathod to achieve it instead using updatepanel.

Sample:

Default.aspx:

<%@. Page Language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title>Untitled Page</title>

<script type="text/javascript">
// This function calls the Web Service method.
function EchoUserInput()
{
var echoElem = document.getElementById("WhichLeafToDelete");
WebService.DeletedLeaf(echoElem.value,SucceededCallback);
}
// This is the callback function that processes the Web Service return value.
function SucceededCallback(result)
{
//Do something to change the html of the tree to delete the leaf.
}
</script>
</head>
<body>
<form id="form1" runat="server">
<asp:ScriptManager ID="ScriptManager1" runat="server">
<Services>
<asp:ServiceReference Path="WebService.asmx" />
</Services>
</asp:ScriptManager>
<div>
<h2>
Simple Web Service</h2>
<p>
Calling a simple service that echoes the user's input and returns the current server
time.</p>
<input id="WhichLeafToDelete" type="text" />
<input id="EchoButton" type="button" value="Echo" onclick="EchoUserInput()" />
</div>
</form>
<hr />
<div>
<span id="Results"></span>
</div>
</body>
</html>

WebService.asmx:

<%@. WebService Language="C#" Class="WebService" %>

using System;
using System.Web;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Web.Script.Services;

[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
[ScriptService]
public class WebService : System.Web.Services.WebService
{
[WebMethod]
public string DeletedLeaf (String input)
{
//Do something to delete the leaf in the database.
}
}

For more help, You can see thesetutorials:
http://ajax.asp.net/docs/tutorials/ExposingWebServicesToAJAXTutorial.aspx.
http://ajax.asp.net/docs/tutorials/ConsumingWebServicesWithAJAXTutorial.aspx

Let me know if you need more info.


Jin-Yu Yin:

I'm a bit confused. The actual display of the tree is a local matter, isn't it? As such, isn't it superfluous about whether to use a web service or code on the page?

What about the Ajax Update Panel wouldn't solve the problem I'm trying to solve?

Robert



Hi, Robert

If you don't need to do something at the server-side, e.g. deleting the leaf in the database, I mean that, If you just delete something at the client-side,you don't need to use a web service or code on the page, just use JavaScript to delete it. it's ok.

If you use an updatepanel to do this, it'll show you this:

+ A

+ B

+ C

because the updatepanel refreshed. It cann't remember what you had did before the postback

Updating multiple controls

I have an asp.net web site. I have many text boxes, drop downs and check boxes that need to be populated based on user input. I have a main text box for them to put in an ID number and a button to run my code. The problem is that the text boxes and check boxes are all over the form so I can't group them in one update panel.

Also, some of the check boxes, drop downs and text boxes can change the data in other controls based on user input. This causes so many post backs under normal conditions. If I put everything in an update panel, isn't that still going to cause just as many post backs?

Putting the whole page in one UpdatePanel will cause pretty much the same amount of data to be sent back to the server (the whole viewstate is always sent) and by the sounds of it pretty much the same amount of data comin back. It would reduce network traffic a bit and get rid of the screen flicker though.

You really need to put just the bits that update in multiple UpdatePanels, they will all get updated when one does. However, I'd go one step further and set all of them to UpdateMode="Conditional" so you can only update the panels you need to when you need to.


Thank you. I looked into that a bit further and also watched a video on multiple update panels. I will try this, conditional updates and add triggers to the update panels. Thanks again.