I am getting an error on javascript when doing post back. The code is as follows:
<%# Page Language="C#" AutoEventWireup="true" CodeFile="test.aspx.cs" Inherits="test" %>
<!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 language="javascript" type="text/javascript">
function DoPostBack()
{
__doPostBack('Button2','My Argument');
}
</script>
</head>
<body>
<form id="form1" runat="server">
<input type="button" id="Button2" value="Press me" onclick="DoPostBack()" />
</form>
</body>
</html>
I am getting the following error:
Line: 13
Error: Object expected
I can't understand why this error is coming. Kindly help...
you can use a hidden button to do this task
Button1.Attributes.CssAttributes.Add("Display","None");
after hiding the button
you can call its click function from javascript
document.getElementById('<%=Button1.ClientID%>').click();
this will call Button1_Click on server
** remember to set UseSubmitBehaviour=false to make this work on non-IE browsers
hope that helps :)
__doPostBack is not created by default. If the page does not have a control that causes a postback then ASP.NET does not create/generate this method.
In your case you can force ASP.NET to generate __doPostBack by adding the following line in you Page_Load event:
ClientScript.GetPostBackEventReference(this, string.Empty);
This line will force the creation of this method.
_doPostBack isn't created by default. It appears when you are adding control with autoPostBack=true or adding some grid with buttons in it.
So there is no _doPostBack javascript generated in your code.
If you add
<asp:DropDownList ID="list" runat="server" AutoPostBack="true">
<asp:ListItem Text="first"></asp:ListItem>
<asp:ListItem Text="second"></asp:ListItem>
</asp:DropDownList>
for instance your code will work.
Don't know if it is really useful code :) however.
Related
I am using the OnClick of the asp:Button tag to compute a report which I would like to display as an innerHTML of a div tag. I would like to use the Response.WriteLine method to return this html file. Does ASP.NET webforms provide a way of capturing this response?
Am I forced to use JavaScript instead? I am using C# on the Server side.
The Web Forms way of doing this is to use a control and set its InnerHTML from the code behind. Here's a self contained example:
<%#Page Language="C#" AutoEventWireup="true" %>
<script runat="server">
protected void GenerateReport(object sender, EventArgs e)
{
var reportHTML = "<p>This is a <span style='font-weight: bold;'>report!</span></p>";
ReportDiv.InnerHtml = reportHTML;
}
</script>
<!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>
<title>Test</title>
</head>
<body>
<form runat="server">
<asp:Button runat="server" OnClick="GenerateReport" Text="Generate Report" />
<div runat="server" id="ReportDiv"></div>
</form>
</body>
</html>
How to fix this problem ?... I am not understanding that !... I have given my HTML code and the error pic ! and it is occouring after adding this line
plz help
<%# Page Language="C#" AutoEventWireup="true" CodeFile="Signin.aspx.cs" Inherits="Signin" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<h1>ESbook</h1>
<asp:Login ID="Login1" runat="server" OnAuthenticate="Login1_Authenticate">
</asp:Login>
</div>
</form>
</body>
</html>
]1
Your codes requires a reference to jQuery libraries.
Before donwloading and referencing the jQuery place this line of code
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
agter <title>tag in your <head> block.
<%# Page Language="C#" MasterPageFile="~/MasterPage.master" AutoEventWireup="true" CodeFile="Default2.aspx.cs" Inherits="Default2" ClientIDMode="AutoID" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="server">
<%
foreach (var item in AllSales)
{
//Here i have just set a breakpoint to see if it loops the AllSales list when I press the update button
}
%>
<asp:UpdatePanel runat="server" ID="UpdatePanel1">
<ContentTemplate>
<p>Update Panel: DateTime.Now: <%= DateTime.Now.ToString() %></p>
<asp:Button runat="server" ID="Submit" Text="Update" />
</ContentTemplate>
</asp:UpdatePanel>
</asp:Content>
The script manager code is in the masterpage :
<asp:ScriptManager ID="ScriptManager1" runat="server" />
<asp:ContentPlaceHolder id="ContentPlaceHolder1" runat="server">
</asp:ContentPlaceHolder>
Problem here is that everytime i click the Update button it loads the page again and loops the "AllSales" list , i want to only update a section and not have to do unnecessary loops.
Here is the fun part : If i remove the masterpage, it works ! But with the masterpage, it dont , why?!
You need to use a server control to initiate the update rather than a normal html input button. Try using:
<asp:Button ID="ActivitySubmit" Text="Submit" runat="server" />
The reason for such behavior is that you use plain html submit button instead of ASP.NET server button. Thus page submitted to server without involving ASP.NET Ajax functionality. Replace ActivitySubmit button with asp:Button control
Set the UpdateMode mode property to Conditional. The default value for UpdateMode is Always, If the UpdateMode property is set to Always, the UpdatePanel control's content is updated on every postback that originates from anywhere on the page, reference
Edit: You are using input type="submit" which probably causing the post back replace it with asp:Button to get the ajax call to work.
I have tested the same code with only change in the button type, and it refreshes only the update panel content. The problem is your site is targeting .NET 3.0 but you need to target at least to 3.5. I have tested on 3.0, it does not work but on 3.5 and 4.0, it works fine. So the easier and safer solution is to target 3.5 onwards. But If you want to use .NET 3.0, I will try to find a workaround. Please let me know.
I tried to recreate your problem but it is working fine in my case. Try creating a new .aspx file and paste the following:
<!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 runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<p>Outside UpdatePanel</p>
<asp:ScriptManager runat="server" ID="ScriptManager1">
</asp:ScriptManager>
<asp:UpdatePanel runat="server" ID="UpdatePanel1">
<ContentTemplate>
<p>DateTime.Now: <%= DateTime.Now.ToString() %></p>
<asp:Button runat="server" ID="SubmitButton" Text="Go" />
</ContentTemplate>
</asp:UpdatePanel>
</div>
</form>
</body>
</html>
This was tested in VS2010 using .NET 4.0 in an Empty Web Application. Does this work for you as well? I tried the same example using a Master page with a content placeholder. This yields the same (properly working) results. From this I gather there is something else going on on your page that we're missing. Is there?
[Edit]
I made another simple example, this time with a Master page and a Content page.
Master page:
<!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 runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:ScriptManager runat="server" ID="ScriptManager1"></asp:ScriptManager>
<p>Master Page: DateTime.Now: <%= DateTime.Now.ToString() %></p>
<asp:ContentPlaceHolder ID="ContentPlaceHolder1" runat="server"></asp:ContentPlaceHolder>
</div>
</form>
</body>
</html>
Aspx page:
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
<asp:UpdatePanel runat="server" ID="UpdatePanel1">
<ContentTemplate>
<p>Update Panel: DateTime.Now: <%= DateTime.Now.ToString() %></p>
<asp:Button runat="server" ID="Submit" Text="Update" />
</ContentTemplate>
</asp:UpdatePanel>
</asp:Content>
Again this works without a problem in the same environment as the other example. It looks like you'll have to tell me about the .NET framework you're targeting and what else you've got set up in your master page and aspx page, because:
In .Net 3.5 and up this will work. In lower versions however, it won't. I'm afraid I've been unable to figure out how to fix it in lower versions though. :(
In your Page tag just add
ClientIDMode="AutoID"
I think you can try and put the form inside the updatepanel, or you can try and change children as triggers property of the updatepanel like this :
<asp:UpdatePanel runat="server" ID="UpdatePanel1" ChildrenAsTriggers="False">
and then add the button as trigger like this
ScriptManager.GetCurrent(Page).RegisterAsyncPostBackControl(SubmitButton);
try addind this part to your UpdatePanel:
<Triggers>
<asp:AsyncPostBackTrigger ControlID="Submit" />
</Triggers>
I'm sure this is RTFM, but I just can't figure out which FM I'm supposed to R.
I'm trying to serve a JNLP (Java Web Start) file (which is an XML format), and ASP.Net insists on appending HTML code to the response body.
More detail: I have a .aspx file and an accompanying .aspx.cs file. These were generated with the "new page" wizard. In Page_Load() in the .aspx.cs file, I generate some XML, do Response.ContentType = "application/x-java-jnlp-file", you know the drill.
The .aspx file, however, contains:
<%# Page Language="C#" CodeBehind="MyPage.aspx.cs" Inherits="MyProj.MyPage" EnableSessionState="False" %>
<!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 runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
</div>
</form>
</body>
</html>
This code is appended to the output.
How do I avoid this? I tried calling Response.End() from Page_Load() but it's reportedly Evil and it throws nasty exceptions. Response.Close() is even worse, and breaks HTTP. I also tried simply removing all the HTML from the body, but ASP then complains about the fact that it needs a <head runat="server"> for something called "Themed CSS" (I'm not sure what that means).
Any leads?
Thanks!
Obligatory Use a Handler.
This gives you all the control necessary over the direct-output of information. The article included even gives an example of outputting an image.
You can turn off themes by adding EnableTheming="false" and Theme="" to Page directive
So your page would become
<%# Page Language="C#" CodeBehind="MyPage.aspx.cs"
Inherits="MyProj.MyPage" EnableSessionState="False"
EnableTheming="false" Theme=""%>
Adding a Response.Clear() before any output should then work as expected. However Brad's comment is spot on, this is perfect for an HTTP Handler
Just have the page as :
<%# Page Language="C#" CodeBehind="MyPage.aspx.cs" Inherits="MyProj.MyPage" EnableSessionState="False" %>
Delete the rest of the HTML in the page and as the poster suggested and do a Response.Clear()..
It is important you delete everything after the end of the
<%# Page Language="C#" CodeBehind="MyPage.aspx.cs" Inherits="MyProj.MyPage" EnableSessionState="False" %> declaration.
With a Response.Clear() or just remove it from the page!
How can I display an html textbox with value obtained from code behinh?
As long as your string value is not private, you should be able to do something like this
<input type="text" value="<%= YourStringValue %>" />
You could use an actual <asp:Textbox /> and set it's "text" value directly from the code behind. If you want to directly inject text into a "normal" html textbox (or anywhere else for that matter), you can use <%= SomeValue %>. Yet another way is to include the "runat=server" attribute on standard html elements, allowing you to manipulate them from the codebehind.
Normally I'd just go for the built-in ASP textbox control so I don't have to worry about persisting values/wiring up viewstate/etc. Injecting dynamic content into plain html elements tends to be an edge case requirement...
<%# Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
//assign text value here
txt1.Value = "hello world!";
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<input id="txt1" runat="server" type="text" />
</div>
</form>
</body>
</html>