I am working on a project in C# .NET that allows me only one form in the .aspx file.
<form id="form1" runat="server" action="#1">
How can I change the form action through the C# code in a method?
I have tried this:
protected void Button1_Click(object sender, EventArgs e)
{
form1.Action = "#2";
}
but it didn't work. Thanks in advance...
Based on the comments to you question. asp:Panel Controls could help you out.
A very rough example
ASPX:
<form id="form1" runat="server">
<asp:Panel id="Form1" runat="server">
<!-- Form 1 Stuff -- >
<asp:Button ID="Button1" runat="server" Text="Submit"
OnClick="Button1_Click" />
</panel>
<asp:Panel id="Form2" runat="server" Visible="false">
<!-- Form 2 Stuff -- >
<asp:Button ID="Button2" runat="server" Text="Submit"
OnClick="Button2_Click" />
</panel>
</form>
C#
protected void Button1_Click(object sender, EventArgs e)
{
//HIde "Form"1
Form1.Visible = false;
//Show "Form"2
Form2.Visible = true;
//Do other stuff
}
protected void Button2_Click(object sender, EventArgs e)
{
//Do Final Processig
}
Also look at the DefaultButton property of the Panel
(Moving this to the top because it's an answer to the newly understood question. It's not how to change the form action, but how to have multiple forms.)
If you want a server form on a page that already has a server form then perhaps that second "form" should be a User Control. That way it sits inside the host page's server form but doesn't require its own form. And it's self-contained, able to contain whatever logic it needs when handling a postback.
Here's an example of a simple User Control. You can create one from Add > New Item > Web > Web Forms User Control.
<%# Control Language="C#" AutoEventWireup="true"
CodeBehind="OtherForm.ascx.cs" Inherits="WebApplication1.OtherForm" %>
<label for="<% = OtherFormTextInput.ClientID %>">
This is some other form on the same page
</label>
<asp:TextBox runat="server" ID="OtherFormTextInput"></asp:TextBox>
<asp:Button runat="server" ID="Submit" Text="Submit this other form"/>
It looks like an .aspx page but it has no form. It can still have its own code behind which can interact with with the other server controls it contains, just like an .aspx page would.
Then you add that control to your "main" page:
<%# Page Language="C#" AutoEventWireup="true"
CodeBehind="WebForm1.aspx.cs" Inherits="WebApplication1.WebForm1" %>
<!-- Register the user control -->
<%# Register TagPrefix="uc" TagName="other" Src="~/OtherForm.ascx" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<!-- This form has its own stuff, but also contains the "other" form. -->
<uc:other runat="server" ID="TheOtherForm"></uc:other>
</form>
</body>
</html>
I recommend this over using panels (which still works) because if you're putting two forms on one page, it's likely that you might at some point want to move the secondary form to another page or re-use it. This approach keeps it completely self-contained. Its code-behind isn't in the same file as the the .aspx page. You can place this on as many pages as you want.
Original "literal" answer which addresses the question as originally understood.
The runat="server" form exists entirely for the purpose of allowing ASP.NET to interact with the page and its server controls during postbacks. It's central to the way webforms works. If you change the action then technically what you have isn't a webforms page any more.
That's fine (I don't even like webforms) but it can lead to some weird behavior. If you have controls that trigger postbacks then normally they'd be handled on the same page and your user would just see a (hopefully) fast refresh. Now they might get sent to another page.
What if you just removed that form entirely and added your own form instead? Then your .aspx page will just behave more like an .html page.
Having added all the disclaimers about why not to do it, you can change the action using JavaScript. Here's a sample:
<%# Page Language="C#" AutoEventWireup="true"
CodeBehind="WebForm1.aspx.cs" Inherits="WebApplication1.WebForm1" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server" ClientIDMode="Static">
<asp:Button runat="server" text="Causes postback"/>
<asp:CheckBox runat="server" AutoPostBack="True"/>
</form>
<script>
document.getElementById("form1").action = "http://stackoverflow.com";
</script>
</body>
</html>
Some browsers might not allow changing the form's action.
I put the checkbox there just for fun (I must be really bored) to show the odd side effects it could have, that you might click on a checkbox and get redirected to a different page.
You can write a response.write() in your Asp.net side that print some javascript or jQuery code! As #Scott Hannen wrote some javascript like this :
Response.Write("<script>document.getElementById('YOURFORMID').action = 'YOUR URL';</script>");
or with jQuery
Response.Write("<script>$('#YOUR FORM ID').attr('action', 'YOUR URL');</script>");
btw if you have access to .html or .js files u can directly put this jQuery code without any C# code!
Related
I have a Default page (initial landing page) with a bunch of asp controls and everything works great. I also have an Admin page with one asp button control (I simplified for the post). Both are wrapped in form element on a Site.Master page. The button click event does not fire on my Admin page. Here is my button event and page code/code behind:
Page code
<%# Page Title="Admin1" Language="C#" MasterPageFile="~/Site.Master"
AutoEventWireup="true" CodeBehind="Admin1.aspx.cs"
Inherits="HPRMWebClientReporting.Admin1" %>
<asp:Content runat="server" ID="AdminContent"
ContentPlaceHolderID="AdminContent">
<asp:Button ID="ButtonGo" runat="server" Text="Button" Width="111px"
OnClick="ButtonGo_Click" />
</asp:Content>
Code Behind
public partial class Admin1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
}
}
protected void ButtonGo_Click(object sender, EventArgs e)
{
this.Context.Items["Msg"] = "It worked!!!.";
Server.Transfer("MessagePage.aspx");
}
}
Here is what happens:
Goes through Page_Load of Default page
Goes through Page_Load of Site.Master page
Refreshes my site and shows the Default page
At no point does it go my click event or Page_Load of my Admin page when the button is clicked? The button click should be taking it to the MessagePage page.
This is driving me crazy. I did try turning Causes Validation to false on the button with no luck. Any ideas?
Note: Also, maybe this will help someone determine what I'm doing wrong. I changed the Page Code so it does not use the MasterPageFile Site.Master and I just wrapped the button in its own form element and it worked fine but I don't want it to work that way as I want to use the Master page.
I found something that worked although I am not entirely sure why without further research. In my Site.Master page and in the form element I mentioned in the post I pulled out the action="/" and now my controls work on Admin page as I expected them too.
<form id="Form1" action="/" method="post" runat="server">
<asp:ContentPlaceHolder ID="HomeContent" runat="server">
</asp:ContentPlaceHolder>
<asp:ContentPlaceHolder ID="ContactContent" runat="server">
</asp:ContentPlaceHolder>
<asp:ContentPlaceHolder ID="AboutContent" runat="server">
</asp:ContentPlaceHolder>
<asp:ContentPlaceHolder ID="AdminContent" runat="server">
</asp:ContentPlaceHolder>
</form>
i want to convert my html file to pdf in that process i took all html tags and elements into an asp textfield on button click its giving the above error
code is
code.aspx
<asp:TextBox ID="TxtHtmlCode" CausesValidation="false" runat="server" Width="90%" Text="" TextMode="MultiLine" Height="150px"></asp:TextBox>
<asp:Button ID="BtnCreatePdf" runat="server" Text="Create PDF" OnClick="BtnCreatePdf_Click" CssClass="mybutton" />
code.aspx.cs
protected void BtnCreatePdf_Click(object sender, EventArgs e)
{
htmlString = TxtHtmlCode.Text;
HtmlToPdf converter = new HtmlToPdf();
PdfDocument doc = converter.ConvertHtmlString(htmlString);
doc.Save(Response, false, "Sample.pdf");
doc.Close();
}
i check with breakpoints even its not going to button click function.
please help me..
You want to use HTML editor like opensource ckeditor.
It'll basically encode and decode html elements when you post the page back to server.
<%# Register Assembly="CKEditor.NET" Namespace="CKEditor.NET" TagPrefix="CKEditor" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<CKEditor:CKEditorControl ID="CKEditor1" BasePath="/ckeditor/" runat="server">
</CKEditor:CKEditorControl>
<asp:Button ID="BtnCreatePdf" runat="server" Text="Create PDF"
OnClick="BtnCreatePdf_Click" CssClass="mybutton" />
</form>
</body>
</html>
FYI: I personally do not like to use validateRequest="false"; it'll end up creating security hole.
Inside of your web.config you'll want to do:
<HttpRuntime requestValidationMode="2.0" />
Your other option, is to also append to your page directive at the top of your .aspx and apply:
<#Page ... validateRequest="false" %>
Keep in mind, by adding to web.config it will affect your entire site, compared to the page directive. However, by adding this to your application, you obviate some built in security that Microsoft utilizes in the Web-Forms Framework.
How to implement two forms one in header and other in body of an ASP.net page with one master page, or how can I display the same form at both the places with only one form?
As to your question:
How to implement two forms one in header and other in body of an ASP.net page with one master page, or how can I display the same form at both the places with only one form?
If you need to choose: Concentrate on the second part.
The general method in Web Forms is to have only one <form> in your page, which is .NET's default <form> that surrounds all the content of your .aspx/.master page.
As the rules of HTML state: You cannot have two nested forms in an HTML page.
It means that if you want to have multiple <form> tags in your page, you will have to use it outside of .NET's default <form>.
Basically it means that all of the forms outside of .NET's one will not be part of the View State and you will not be able to use ASP.NET web controls.
However, if you are still considering the first method, you can read some more about it here:
Can we use multiple forms in a web page?
And you can see a really good example implementing it here:
Using multiple forms on an ASP.NET web forms page
Display the same form at two places
Basically, it is an essential part of Web Forms and is used many times.
You can create as many forms as you like by associating as many <asp:Button> elements as you like to different Click events.
To make two forms in the master, one in the header and one in the body:
Put the form contents in the two sections and use two different submit button handlers in the code behind (See example below)
Put in your MasterPage multiple ContentPlaceHolder elements. Use one for each place you would like to load content from your .aspx file.
In your .aspx refer to the ContentPlaceHolder elements with the corresponding ContentPlaceHolderIDs
In this example you can see one form in the Header section and another in the Body section like you wanted:
MasterPageTwoSections.master
<%# Master Language="C#" AutoEventWireup="true" CodeFile="MasterPageTwoSections.master.cs" Inherits="MasterPageTwoSections" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<asp:ContentPlaceHolder id="head" runat="server">
</asp:ContentPlaceHolder>
<style>
header {
background-color:red;
}
.body {
background-color:green;
}
</style>
</head>
<body>
<form id="form1" runat="server">
<div>
<header>
<asp:ContentPlaceHolder id="HeaderPlaceHolder" runat="server">
<%--Placeholder for the pages--%>
</asp:ContentPlaceHolder>
<h5>
This is form #1 from the master
</h5>
<asp:TextBox runat="server" ID="txtFirstForm"></asp:TextBox>
<asp:Button runat="server" ID="btnFirstFormSubmit" OnClick="btnFirstFormSubmit_Click"
Text="Submit first form" />
</header>
<section class="body">
<asp:ContentPlaceHolder id="BodyPlaceHolderBeforeForm" runat="server">
<%--Placeholder for the pages--%>
</asp:ContentPlaceHolder>
<h5>
This is form #2 from the master
</h5>
<asp:TextBox runat="server" ID="txtSecondForm"></asp:TextBox>
<asp:Button runat="server" ID="btnSecondFormSubmit" OnClick="btnSecondFormSubmit_Click"
Text="Submit first form" />
<asp:ContentPlaceHolder id="BodyPlaceHolderAfterForm" runat="server">
<%--Placeholder for the pages--%>
</asp:ContentPlaceHolder>
</section>
</div>
</form>
</body>
</html>
MaterPageTwoSections.master.cs
Notice the two submit handlers:
using System;
public partial class MasterPageTwoSections : System.Web.UI.MasterPage
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void btnFirstFormSubmit_Click(object sender, EventArgs e)
{
}
protected void btnSecondFormSubmit_Click(object sender, EventArgs e)
{
}
}
FirstPage.aspx
Notice Content2 refers to HeaderPlaceHolder in the MasterPage.Content3 and Content4 refer to BodyPlaceHolderBeforeForm and BodyPlaceHolderAfterForm
<%# Page Title="" Language="C#" MasterPageFile="~/MasterPageTwoSections.master"
AutoEventWireup="true" CodeFile="FirstPage.aspx.cs" Inherits="FirstPage" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="HeaderPlaceHolder" Runat="Server">
<p>
This header content is from the FirstPage.aspx
</p>
</asp:Content>
<asp:Content ID="Content3" ContentPlaceHolderID="BodyPlaceHolderBeforeForm" Runat="Server">
<p>
This body content is from the FirstPage.aspx
</p>
</asp:Content>
<asp:Content ID="Content4" ContentPlaceHolderID="BodyPlaceHolderAfterForm" Runat="Server">
<p>
This body content is from the FirstPage.aspx
</p>
</asp:Content>
I have a simple web page that contains a Literal, now I want to create a form tag in code behind.
This is an example:
if (IsPostBack)
{
Literal1.Text = "form submit";
}
else
{
Literal1.Text = "<form id='myFrom' runat='server' action='default.aspx'
method='POST'><input type='submit' value='click here'/></form>";
}
This code create the form, but when I click the submit button, it doesn't go through IsPostBack path. Why?
Note that I need it to be created and sent as an string, because I want to use it in ajax for example.
IsPostBack is only enabled when the POST request originates from ASP.NET's __doPostBack() function. See How to use __doPostBack() for how to create an async postback request with JavaScript.
An ASP.NET web form is already an HTML form and encompasses all of your controls. You are nesting a form within a form which is not legal HTML.
I'd suggest you replace your nested form with a simple button. In the click handler for the button, redirect to default.aspx.
As indicated by John Wu, you don't want to implement your code this way. Nested forms -- while browsers forgive them -- are just not the way to go, especially with ASP.Net WebForms. Sure, I was able to get your code to work, BUT if you need to ajaxify your page so that it works with the WebForms postback model, then it would be much better to use the UpdatePanel control (in conjunction with the ScriptManager control).
ASP.Net WebForms is predicated on only having a single Form element used on a page, as it relates to its postback model, so you'll want to work within that constraint.
Here's some code to demonstrate the use of the UpdatePanel to ajaxify a WebForm (and take advantage of PostBack):
...the .ASPX page:
<%# Page Language="C#" AutoEventWireup="true" CodeBehind="NestedForm_Question.aspx.cs" Inherits="StackOverflowAspNetQuestionAnswers.NestedForm_Question" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:ScriptManager ID="ScriptManager" runat="server" />
<asp:UpdatePanel runat="server">
<ContentTemplate>
<asp:Literal ID="Literal1" runat="server" />
<asp:Button ID="SubmitButton" Text="Submit" runat="server" />
</ContentTemplate>
</asp:UpdatePanel>
</div>
</form>
</body>
</html>
...the associated code-behind class:
public partial class NestedForm_Question : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
SubmitButton.Click += SubmitButton_Click;
}
void SubmitButton_Click(object sender, EventArgs e)
{
Literal1.Text = "form submit";
}
}
You can see that in the code-behind class, the code that would need to be written to set the value of the literal control after the Button is clicked is the same whether the page is ajaxified or not.
I've changed my code to this:
if (Context.Request.Form.HasKeys()) // instead of if(IsPostBack)
{
Literal1.Text = "isPostBack";
}
else
{
Literal1.Text = "<form id='myFrom' runat='server' action='default.aspx' method='POST'><input type='submit' name='submitbtn' value='click here'/></form>";
}
Using different examples, I didn't find any exception to this. and it works well.
Any idea about this solution?
Note that in this way at least one of our elements in the form should have the name property.
I am building an ASP.NET application and would like to use a master page to display branding and navigation info and move through several content pages. However, every time I try to load new content the entire page flickers. Is there anyway to avoid this?
Master page:
<%# Master Language="C#" AutoEventWireup="true" CodeBehind="Site.master.cs" Inherits="Interface.Site" %>
<%# Register TagPrefix="customControl" TagName="NavigationBar" Src="NavigationControl/NavigationControl.ascx" %>
<!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>Registration</title>
<asp:ContentPlaceHolder ID="head" runat="server">
</asp:ContentPlaceHolder>
<link href="Stylesheet.css" rel="stylesheet" type="text/css" />
</head>
<body>
<form id="RegistrationMasterForm" runat="server">
<div>
<asp:ScriptManager ID="ScriptManager" runat="server" EnablePartialRendering="true">
</asp:ScriptManager>
<%-- Contents of this div span the top of the page for branding --%>
<div id="BrandingBanner">
<asp:Image ID="Banner" runat="server"
ImageUrl="Images/BrandingBanner.png"/>
</div>
<%-- Navigation Bar, the contents of this div should remain unchanged --%>
<div id="NavigationBar">
<customControl:NavigationBar ID="navBar" runat="server"/>
</div>
<%-- Contains any forms or controls that may be uniquie to the page --%>
<div id="FormControls">
<div id="FormContent">
<asp:ContentPlaceHolder ID="ContentPlaceHolder1" runat="server">
</asp:ContentPlaceHolder>
</div>
</div>
</div>
</form>
</body>
</html>
Content:
<%# Page Language="C#" MasterPageFile="~/Site.Master" AutoEventWireup="true" CodeBehind="WebForm2.aspx.cs" Inherits="Interface.WebForm2" Title="Untitled Page" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
Check me out! I am content for the master page!
<asp:Button ID="Button1" runat="server" Text="Next" onclick="Button1_Click" />
</ContentTemplate>
</asp:UpdatePanel>
</asp:Content>
content code behind:
public partial class WebForm2 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click(object sender, EventArgs e)
{
Response.Redirect("WebForm3.aspx");
}
}
The control event triggers a post back to your page, which typically creates the "blanking" effect that you see. To mitigate this, you may want to consider using some sort of Ajax solution to cause a partial postback or async postback to prevent the "blanking".
However in the particular case of your button click, if all you are trying to do is bring the use to another page, you really should just use an <a href="WebForm3.aspx"> tag and avoid using Response.Redirect.
You are redirecting the page in your codebehind.
This causes the browser to change pages, and redraw the whole thing, at least IIRC. I haven't used updatepanels in ages.
Isnt this only possible if you're using frames? As far as I'm aware the master page and content pages bind together on the serverside and push down the the client as a whole.
Where what you want sounds like using an page for branding and navigation with an inline frame to serve up your convent. This would prevent the outer page from "flickering" on the client side.
Edit: Though it is not the new way to do things. You'd want to look at something using maybe an UpdatePannel or other AJAX style design.
You don't need to move the updatepanel, your redirect is causing the browser to load a new page.