473,695 Members | 2,810 Online
Bytes | Software Development & Data Engineering Community
+ Post

Home Posts Topics Members FAQ

What is the difference between PostBack & Callback? Please give sample code?

24 New Member
Folks!

What is the difference between PostBack and Callback ( !IsPostBack and if(!IsCallback) )

Like in the following Code Snippet:
Expand|Select|Wrap|Line Numbers
  1.         protected void Page_Load(object sender, EventArgs e)
  2.         {           
  3.             if (!IsPostBack)
  4.             {
  5.  
  6.             }
  7.  
  8.             if(!IsCallback)
  9.             {
  10.  
  11.             }
  12.         }


As far as I know, when I 1) refresh the page or 2) revert back to the page after round trip, the behavior is such that IsPostBack = !IsCallback. I don't find any difference.

Can you please explain with example code?

Just want a sample code (for Page_Load event) that will demonstrate the difference in the Page_Load event so that I can toggle breakpoint and understand it for myself.

Thanks.
Oct 24 '09 #1
2 4108
PRR
750 Recognized Expert Contributor
A Postback occurs when the data (the whole page) on the page is posted from the client to the server.During a page postback, the Web page and controls are recreated and a new version of the entire Web page is rendered on the client.

Callback is also a special kind of postback, but it is just a quick round-trip to the server to get a small set of data.
Link

Determine How ASP.NET Web Pages Were Invoked
Page.IsPostBack
Page.IsCallback
Oct 27 '09 #2
qwedster
24 New Member
Thanks for the reply!
Nov 3 '09 #3

Sign in to post your reply or Sign up for a free account.

Similar topics

1
11573
by: Earl Teigrob | last post by:
I did a ton of searching to try and find a simple solution to this issue and finally wrote my own, which I am sharing with everyone. In my searching, I did find a very complete and robust solution at http://weblogs.asp.net/asmith/archive/2003/09/15/27684.aspx but it was far more complex then I needed. (I got lost trying to figure it all out). Therefore, here goes my simple "web dialog box with parent event handler fireing" solution. ...
12
17399
by: Nathan Sokalski | last post by:
What is the difference between the Page_Init and Page_Load events? When I was debugging my code, they both seemed to get triggered on every postback. I am assuming that there is some difference, and I would like to know what it is so that I can take advantage of it in my code. Thanks. -- Nathan Sokalski njsokalski@hotmail.com http://www.nathansokalski.com/
4
3406
by: Jim Hammond | last post by:
It would be udeful to be able to get the current on-screen values from a FormView that is databound to an ObjectDataSource by using a callback instead of a postback. For example: public void RaiseCallbackEvent(string eventArgs) { // update the data object with the values currently on screen FormView1.UpdateItem(true); }
2
620
by: Wizzard | last post by:
I have a repeater with and imagebutton on a page useing VS2005 ASP.Net 2.0 <asp:Repeater ID="Repeater1" runat="server" > <ItemTemplate> <div> <asp:ImageButton ImageUrl="button.gif" ID="ImageButton1" runat="server" /> <p><%# Eval("Name") %></p> </div> </ItemTemplate>
3
1589
by: Angel Of Death | last post by:
A postback and a callback. Does a callback always avoid a page being re-sent in it's entirety back to the client and does a post-back always force a browser to reload an entire page? Is this my right understanding? If so, why is it that people say that a callback is a postback.
3
2752
by: teo | last post by:
Mozilla error on postback and validation ----------- A Button causes a Listbox to desappear. If no item has been selected on the Listbox, all is OK. If one or more items are selected,
2
2173
by: Nathan Sokalski | last post by:
I have a DataList in which the ItemTemplate contains two Button controls that use EventBubbling. When I click either of them I receive the following error: Server Error in '/' Application. -------------------------------------------------------------------------------- Invalid postback or callback argument. Event validation is enabled using <pages enableEventValidation="true"/in configuration or <%@ Page EnableEventValidation="true"...
3
5141
by: pearcewg | last post by:
All: I have a page with a form and fields on the form (checkboxes, grids, etc). This form contains a usercontrol which has a dynamic navigational menu of buttons. When a user clicks on one of the buttons in the usercontrol, it is intended to save the updates information on the parent form. This is done using a delegate/callback function to save the data. The callback works great, and the save method is called on the parent
9
4556
by: 200dogz | last post by:
Hi guys, I want to have a button which opens up a new window when pressed. <asp:Button ID="Button1" runat="server" Text="Open new window" /> ... Button1.Attributes.Add("OnClick",
0
8647
marktang
by: marktang | last post by:
ONU (Optical Network Unit) is one of the key components for providing high-speed Internet services. Its primary function is to act as an endpoint device located at the user's premises. However, people are often confused as to whether an ONU can Work As a Router. In this blog post, we’ll explore What is ONU, What Is Router, ONU & Router’s main usage, and What is the difference between ONU and Router. Let’s take a closer look ! Part I. Meaning of...
0
8585
by: Hystou | last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can effortlessly switch the default language on Windows 10 without reinstalling. I'll walk you through it. First, let's disable language synchronization. With a Microsoft account, language settings sync across devices. To prevent any complications,...
0
8835
tracyyun
by: tracyyun | last post by:
Dear forum friends, With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each protocol has its own unique characteristics and advantages, but as a user who is planning to build a smart home system, I am a bit confused by the choice of these technologies. I'm particularly interested in Zigbee because I've heard it does some...
0
7681
agi2029
by: agi2029 | last post by:
Let's talk about the concept of autonomous AI software engineers and no-code agents. These AIs are designed to manage the entire lifecycle of a software development project—planning, coding, testing, and deployment—without human intervention. Imagine an AI that can take a project description, break it down, write the code, debug it, and then launch it, all on its own.... Now, this would greatly impact the work of software developers. The idea...
1
6504
isladogs
by: isladogs | last post by:
The next Access Europe User Group meeting will be on Wednesday 1 May 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM). In this session, we are pleased to welcome a new presenter, Adolph Dupré who will be discussing some powerful techniques for using class modules. He will explain when you may want to use classes instead of User Defined Types (UDT). For example, to manage the data in unbound forms. Adolph will...
0
5842
by: conductexam | last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and then checking html paragraph one by one. At the time of converting from word file to html my equations which are in the word document file was convert into image. Globals.ThisAddIn.Application.ActiveDocument.Select();...
1
3023
by: 6302768590 | last post by:
Hai team i want code for transfer the data from one system to another through IP address by using C# our system has to for every 5mins then we have to update the data what the data is updated we have to send another system
2
2285
muto222
by: muto222 | last post by:
How can i add a mobile payment intergratation into php mysql website.
3
1986
bsmnconsultancy
by: bsmnconsultancy | last post by:
In today's digital era, a well-designed website is crucial for businesses looking to succeed. Whether you're a small business owner or a large corporation in Toronto, having a strong online presence can significantly impact your brand's success. BSMN Consultancy, a leader in Website Development in Toronto offers valuable insights into creating effective websites that not only look great but also perform exceptionally well. In this comprehensive...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.