How to call codebehind function without postback with ajax - c#

I have a controller:
<asp:Button OnClick="MyFunction" runat="server" />
I want to be able to call MyFunction without the page reloading. Is this possible with ajax or something? If so how would I do it?

Checkout the ASP.Net instructional videos. Should cover most, if not all, of your questions.
AJAX Videos: The Official Microsoft ASP.NET Site

You have to download Ajax Extensions and install it.
After you do this place instead <asp:Button OnClick="MyFunction" runat="server" /> the following
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:Button ID="Button1" runat="server" Text="Your Text" OnClick="MyFunction" />
</ContentTemplate>
</asp:UpdatePanel>
MyFunction would be a c#/vb function written in your page behind code, not a javascript function. I specified this because i've seen many mistakes that people make regarding this one. OnClick attribute is for c#/vb function and OnClientClick is for javascript function.
For more information regarding how to add ajax functionality to an ASP .NET Page go here

One option is to use page methods.
Add a static method to your page, decorated with the WebMethod attribute:
[WebMethod]
public static void MyMethod(string someParam)
{
}
Enable page methods in your ScriptManager:
<asp:ScriptManager EnablePageMethods="True" ... />
And then you can call it from the client side, using JavaScript (that you can wire to the OnClientClick event of your button):
PageMethods.MyMethod("some value", successCallback, errorCallback);
For more details read the "Calling Static Methods in an ASP.NET Web Page" section on this page:
http://msdn.microsoft.com/en-us/library/bb398998.aspx

Yes you can use Make Client-Side Network Callbacks with Asp.net Ajax using this function you can call your code behind methods without reloading your page. To use this methods you should write your methods as static type.
You can refer this video
http://www.asp.net/ajax/videos/how-do-i-make-client-side-network-callbacks-with-aspnet-ajax
You have one more option using the jQuery Ajax.

The simplest way is to warp your code with an UpdatePanel
There are many examples if you google it.

<asp:Button runat="server" ID="btnShowModal" Text="Show"
OnClick="btnShowModal_Click" />
<asp:Button runat="server" ID="HiddenForModal" style="display: none" />
<ajaxToolKit:ModalPopupExtender ID="Modal1" runat="server"
TargetControlID="HiddenForModal" PopupControlID="PopupPanel" />......it may help u

Related

Need to click button twice to get search results

I'm just starting with ASP.NET in college, and I'm stuck on this one:
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:Button ID="searchGmapButton" runat="server" Text="Search" OnClientClick="SetMap();" />
when I click this button it calls JavaScript, that gets value from textbox and uses google maps api to show map and return longitude and latitude. Then I'm putting those into two hidden textboxes,
$("#MainContent_latBox").val(Marker.getPosition().lat().toString());
$("#MainContent_lngBox").val(Marker.getPosition().lng().toString());
so I can use them in aspx.cs code, that displays closest locations using db search. I'm using for this OnTextChanged="lngBox_TextChanged" on one of those hidden textboxes. Problem is that when I click searchGmapButton it displays map location, and lngBox_TextChanged is working on second click.
I tried to use OnClientClick to run JavaScript and OnClick to run asp code,
<asp:Button ID="searchGmapButton" runat="server" Text="Search" OnClientClick="SetMap();" onclick="Button1_Click"/><br />
but then OnClick code is not working at all. Same happens with first example when I move searchGmapButton outside AJAX UpdatePanel.
Did I missed something silly, or did I got it completely wrong?
Write your java script Function
<asp:UpdatePanel>
<ContentTemplate>
<script type="text/javascript">
// Your Java Scrip Code Here
</script>
</ContentTemplate>
</asp:UpdatePanel>

UpdatePanel, Placeholder, User Control loaded by Ajax post

I can successfully add a user control dynamically using the following code.
ASPX:
<asp:PlaceHolder ID="PlaceHolder1" runat="server" />
Code Behind:
UserControl uc = (UserControl)Page.LoadControl
("~/App_Controls/Site/Player/PlayerProfile2.ascx");
PlaceHolder1.Controls.Add(uc);
Now I want to load the user in response to a button click. I have code that submits a form by doing an ajax post.
$(document).ready(function () {
var options =
{
success: showResponse,
url: "/Default.aspx",
type: "post"
};
$('#btnClick').click(function () {
$("form").ajaxSubmit(options);
return false;
});
});
function showResponse(responseText, statusText, xhr, $form)
{
alert(responseText);
}
<asp:Button ID="btnClick" ClientIDMode="Static" runat="server" Text="Click" />
<asp:ScriptManager ID="ScriptManager1" runat="server"></asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
<ContentTemplate>
<asp:PlaceHolder ID="PlaceHolder1" runat="server" />
<asp:Literal ID="litText" runat="server" />
</ContentTemplate>
</asp:UpdatePanel>
I am a newbie to C#. When the placeholder or the literal are changed I w
Instead of using jQuery AJAX, I would use the built in ASP.NET AJAX; it will provide a simpler experience for you. http://weblogs.asp.net/sanjeevagarwal/archive/2008/07/22/Dynamically-create-ASP.NET-user-control-using-ASP.NET-Ajax-and-Web-Service.aspx. By moving the button inside the UpdatePanel, any PostBack that the button generates will be intercepted by the .NET framework and submitted as a partial postback (using AJAX). This should give you a solid starting point for how to achieve what you're after using the .NET AJAX style.
<asp:ScriptManager ID="ScriptManager1" runat="server"></asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
<ContentTemplate>
<asp:Button ID="btnClick" ClientIDMode="Static" runat="server" Text="Click" />
<asp:PlaceHolder ID="PlaceHolder1" runat="server" />
<asp:Literal ID="litText" runat="server" />
</ContentTemplate>
</asp:UpdatePanel>
In the CodeBehind file, you can use IsPostBack to conditionally show or hide your user control.
However, if you'd prefer to stick with your current approach, this blog has a good example that's more complete than what I could type here: http://www.aspsnippets.com/Articles/Dynamically-load-and-display-ASPNet-UserControl-using-jQuery-AJAX-and-WebMethod.aspx
UserControls (ASCX) get attached to the page during server-side rendering and cannot be created with Javascript the way standard HTML elements can. I would suggest using a div containing standard HTML elements as opposed to a user control and using a Javascript library such as Jquery to create copies of this div when applicable.

how to refresh a portion of a page in intervals

I have a page that above it I want to have a panel that automatically refresh every 5 minutes, and if a user has a message in his inbox show to him. What is the best solution for this?
Should I usel AJAX, jQuery, or JavaScript? My preferred solution is server side solution.
Since you are working with ASP.Net, you can also achieve this behavior by using a combination of the following:
ScriptManager or ScriptManagerProxy (if you have nested pages):
Manages the ajax calls
UpdatePanel: Determines what gets updated. Controls nested within <ContentTemplate> are subject to partial
updates
Triggers: Controls when the content is updated.
For your purpose, a Timer control can be used as a trigger to ensure that partial postbacks are triggered every 5 seconds:
<asp:ScriptManager ID="scriptManagerMain" runat="server"/>
<asp:Timer ID="timer" Interval="5000" runat="server"/>
<asp:UpdatePanel runat="server">
<ContentTemplate>
<asp:Panel ID="panelToBeUpdated" runat="server">
<asp:Label ID="lblContent" runat="server" ></asp:Label>
</asp:Panel>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="timer" />
</Triggers>
</asp:UpdatePanel>
I would use Jquery to send an AJax request to the server to fetch the updated content. Upon receiving the content I would use JQuery again to update the markup.
You can set this up to trigger every 5 min using setInterval in Javascript
Hard to give a specific example without code. But you basically need to load the new content with an ajax request that is triggered by a timer.
setInterval(function(){
$.ajax({
url: "someUrlThatServesUpdatedContent.aspx",
cache: false
}).done(function( html ) {
$("#results").html(html);
});
}, 300000);
The above is just a simple example to point you in the right direction.
Edit: Here is an example of how to do the ajax call without JQuery
https://stackoverflow.com/a/2792721/1059001
It's possible to do that with AJAX using method described by previous answers, but if you wish to have a server side solution I would recommend loading that part of the page in an iframe, with meta refresh:
<meta http-equiv="refresh" content="300">
This method however would make it difficult to communicate any events or user actions back to main page.

How to call server-side function from client-side in ASP.NET?

I have a web page having asp.net button control and textbox. I want a confirm message box, when someone changes the content of textbox and click on button. If user click on yes then event of button should fire other wise nothing should happen. All I want is to implement AJAX call back, but it is not working with ASP.NET button control.
Just add the following code to your aspx code
<asp:Button ID="btn1" OnClientClick="return confirm('sure?');" runat="server" Text="Button" />
You can use the ConfirmButtonExtender of the AjaxControlToolkit for this purpose,
http://www.asp.net/ajax/ajaxcontroltoolkit/Samples/ConfirmButton/ConfirmButton.aspx
You can also do using Client Callback in ASP.Net, It is really nice feature in ASP.Net
Please refer to http://msdn.microsoft.com/en-us/library/ms178208.aspx. Hope it helps :)
Combining the use of OnClientClick with javascript's confirm as suggested by Pilgerstorfer Franz, with an update panel for the ajax request you mentioned...
<asp:UpdatePanel runat="server">
<ContentTemplate>
<asp:TextBox ID="txtInput" runat="server"/>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="btnSubmit" />
</Triggers>
</asp:UpdatePanel>
<asp:Button ID="btnSubmit" OnClientClick="return confirm('Are you sure you want to submit?');" runat="server" Text="Submit" />
Should give you want you need.

Is it possible to re-execute javascript in an UpdatePanel?

I have the following:
<asp:UpdatePanel ID="upd" runat="server">
<ContentTemplate>
<script> alert("execute again"); </script>
<asp:LinkButton ID="go" runat="server" Text="Exec JS" />
</ContentTemplate>
</asp:UpdatePanel>
The first time the page renders the script is executed. If I click the button to cause a postback it doesn't execute again.
Is there a way to make it execute the scripts again?
Yo! There's an easy way to get the JavaScript to run again. Put the javascript on the HeadContent portion of your page:
<script>
function BindIt()
{
alert("execute again");
}
</script>
then on your page inside the update panel add portion with a call up to the function that you created for your javascript:
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<script type="text/javascript">
Sys.Application.add_load(BindIt);
</script>
...
In a project that I was working on, I wanted all of the javascript on the page to run again, so I just put it all into a massive BindIt style function. It took me a while to figure it out and I tried many methods to get this to work but this was the only way I was ever able to get jquery to work with updatepanels
Since ASP is just pushing the raw data, not actually executing it you'll need to probably use the RegisterStartupScript method of the ScriptManager to programmatically inject the script to load after a partial postback.
EDIT
More directly, try looking in to ScriptManager.RegisterStartupScript() for UpdatePanels. e.g.
If the JavaScript is jQuery related, following link would definitely help:
http://weblogs.asp.net/hajan/archive/2010/10/07/make-them-to-love-each-other-asp-net-ajax-updatepanels-amp-javascript-jquery-functions.aspx
I have personally used the 2nd method mentioned in this article, and it worked for me properly.

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