<form> action when using Server.Transfer() - c#

I am using Server.Transfer() to transfer processing from one page to another. The problem is that the form action in the source of the page, having been transferred, refers to the destination page and not the original page as per the URL in the browser.
Is there a way to make the action of the form reflect the URL in the browser, rather than the actual destination page?
Thanks in advance!
Mark

Not to worry, I've rewritten my routing code using the System.Web.Routing namespace so all the logic is centralised in my global.asax. Works a treat!
Thanks for your help.
Mark

if you give the form an id you might be able to change the action in the attributes property.
<form runat="server" id="form1" action="">
</form>
and then in the code refer to the form like this:
form1.Attributes["action"] = "new action";
changing the action will probably cause postback events intended for the new page to work incorrectly. Your other alternative if your design permits would be to use the Response.Redirect.
Also, you might want to look into PostBackUrl for the buttons on the new page, which will change the page that they post to.

You should investigate if HttpContext.RewritePath might be useful here. Typically in cases like this you would use rewrite path on the PreRender event of the destination page using the URL of the original page. This causes controls that use the current internal path to generate URLs and such to "think" they are still on the original URL at the time they render themselves.

Related

Getting hidden control of parent from iFramed code-behind

In my parent page I have a hidden control:
<input type="hidden" id="CaseID" value="" runat="server" />
I need for my page in the iFrame to be able to get this value from C# code-behind. I have so far been unsuccessful.
In the child page's code-behind I have tried variations of this:
var theParent = this.Page.Parent;
But I always get null back.
Any assistance would be greatly appreciated.
From the server's perspective, there is no relationship at all between a page which launches an iframe, and the page which is contained within that iframe. They are two completely distinct and unrelated HTTP Requests. In your code-behind, they have nothing in common and there is no way to refer to one from the other.
Thus, you'll need to use the same approach as you would if you needed to "move" data from one page to another. Two common ways (though by no means are these the only ways or even the best ways) are:
The Session object. PageABC can store a piece of data in the session, and PageXYZ can read that data from the session.
URL Parameter on the request. PageABC can call a URL (maybe even use it as the SRC of an iFrame, hint-hint) something like this: PageXYZ.aspx?someKey=someValue. PageXYZ can access URL params from the Request object (Request["someKey"])
Something else to consider: if PageABC and PageXYZ operate in conjunction with each other, maybe having them be separate pages isn't the best approach. It may make more sense for PageXYZ to actually be ControlXYZ and be contained on PageABC. It can still be presented to the user as a popup using jQuery dialogs (or using UpdatePanels and ModalPopupExtenders, if you're masochistic ;).

How do I redirect to a website using MVC?

I am having a hard time figuring out how to redirect to an outside source.
in my code, I have
<%= Html.ActionLink("New Name Search", "Index") %>
which will allow me to navigate within the code.
how do I redirect to ...google for example?
google
The purpose of the ActionLink helper is to generate links that will direct the user to a controller action that you've defined.
If you want to navigate the user to an outside source you should just use a regular anchor tag.
Response.Redirect("http://google.com/");
(It's not really MVC-specific, by the way)
If you are redirecting from your controller (or action filter, etc.) you can use the RedirectResult as your ActionResult type:
RedirectResult("http://www.google.com");
This is essentially doing a Response.Redirect, but is the preferred way of sticking with ASP.NET MVC conventions.
If you are just creating a link inside a View, just use Click to go to Google.
"Redirecting" means many things.
If you just want to show a link that redirects the user to another URL you can use the anchor tag normally in you templates.
google
Now, if you want to redirect the user within the controller, call the Redirect Method.
Result("http://www.google.com");

Context rewritepath problem with form C#

i have a problem when i RewritePath in HttpContext,
context.RewritePath(Utility.WebRoot + "List/Add.aspx", false);
It work fine to rewrite the url: http://localhost/List/Add
But when i hit the button it redirect me to http://localhost/List/Add.aspx
Is there a good way to "stop" the redirection to the .aspx page and just leave it on http://localhost/List/Add ?
Thanks for help
There is an issue with the From tag. You have to use a Control Adapter like this one:
http://weblogs.asp.net/scottgu/archive/2007/02/26/tip-trick-url-rewriting-with-asp-net.aspx
Go to the "Handling ASP.NET PostBacks with URL Rewriting" section.
This will help:
http://www.codeproject.com/KB/aspnet/SmartFormControl.aspx
Basically the idea is to create a new Form control (I called my "ActionlessFormControl") that derives from the .Net Form control. The gist of it is that you override the rendering of the attributes and set your own value for the "action" attribute. What I do in mine is I remove the "action" attribute altogether which will post back to the same URL. Meaning, your page will post back to "/List/Add".
The benefit from using the inherited control is that you don't have to "register" each page. This will allow you to have dynamic content/URLS post back correctly.

How do I HTTP POST from an ASP.NET button?

Sorry, another super basic ASP.NET question. this so embarrassing.
I am reading the article on How to: Pass values between ASP.NET pages
In the second approach, they suggest hooking up a button and directing the user to another page using POST. I don't know how to do this. How do I HTTP POST?
"When the source page uses the HTTP POST action to navigate to the target page, you can retrieve posted values from the Form collection in the target page."
This is how I am sending the user to the new page:
protected void btnSubmitForPost_Click(object sender, EventArgs e)
{
Response.Redirect("GetViaPost.aspx");
}
EDIT
The final solution:
You can use ASP.NET webforms. Do the following: On the first page, create your controls and a button that sends the user to a new page. Handle the click event from this button. As stated below, use Server.Transfer with endResponse=false, instead of Response.Redirect(). When you use Response.Redirect, your post data is cleared out. I did not need to specify action in the form or anything else.
In ASP.NET when you click a button, you're posting the entire page's fields by default (as it's contained within a gigantic <form /> tag last time I checked. You can access these values after clicking the button like this:
string MyPostedValue = Request.Form["MyFormField"];
*Edit as per your update in your question, change Response.Redirect() to Server.Transfer() like this:
protected void btnSubmitForPost_Click(object sender, EventArgs e)
{
Server.Transfer("GetViaPost.aspx", true);
}
Then in your GetViaPost.aspx's page you can get any form/query string variable you passed from your sending page like this:
string MyPostedValue = Request.Form["MyFormField"];
If I'm reading this right, all of these answers are missing the question...
You're looking at posting from one Asp.Net form to another, and one of the methods is what you want to figure out - doing a normal http post. The book or article probably is already telling you about the Server.Transfer as another option if I'm guessing right.
If I'm getting the question right, then the simplest answer is to not use a standard ASP.Net form (with the runat = server attribute) as the starting point, but to use a simple standard html form to post to an asp.net page
<form action = "targetpage.aspx" method="post">
...some form fields here
<input type = "submit">
</form>
If in the codebehind you wire up to the button click event, then click the button. It's a POSTback that happens.
Any controls that you have runat="server" will be accessible by their id (and any values set on them) in the codebehind.
In terms of posting data to other pages, you have a number of options available to you.
The querystring, sessions, cookies and viewstate.
A basic example (with no error handling) given your updated Response.Redirect might be:
int someId = int.Parse(txtBoxOnThePage.Text);
Response.Redirect(string.Format("GetViaPost.aspx?myId={0}", someId));
Then on the GetViaPost page you could pull that out by:
HttpContext.Current.Request.QueryString["myId"]
http://www.asp.net/learn/ is a surprisingly good source of information and tutorials for this kind of learning.
ASP.NET buttons always perform a POST. You can set which page the button posts to using the PostBackUrl property of the button. If you leave this blank, the button will post back to the same page that is resides on.
Check out this article for more information.

Passing master page form data to another webform

I have a master page with one form on it. It is a search form which must always be visible. When the button of that form is clicked I want the form data to be sent to search.aspx. The problem is, I don't know how. I cannot set the form action to search.aspx, because all my other pages which use the master form will go to search.aspx. This I don't want.
Hope someone can help me out :)
Thnx.
In order to pass the values of the control "txtSearch", when Server.Transfer is executed, you could do many things, including passing it via a querystring variable or setting up a session variable, and then check either of those in the Page_Load event of Search.aspx, and if it's populated, call the event that is fired when the user would hit the submit button on the Search.aspx page.
Also, if the Search.aspx file is using the same masterpage, then you can use this.Master.FindControl("txtSearch") to get the control (it you look a the source of the file after it is generated in the browser, you'll notice that controls in the master page aren't really called by their ID, rather that have something appended to them (i.e. it would now possibly be called "ctl00_txtSearch")
You could create your search form in a separate form, and get it to use GET instead of POST.
Either that, or have the master form handle the search button click and use Server.Transfer to go to the search form.
You can have multiple forms in one page I believe. So one form (your search form) would have its action set to search.aspx and the other would be set for the page itself.
ASP.NET webform pages only have one form (which would generally be included on the master page). You can set the postback url for the search button to your search page..
<asp:Button ID="btnSearch" runat="server" Text="Search" PostBackUrl="~/search.aspx" />
..or just redirect to it from the handler in your master page like this:
protected void btnSearch_Click(object sender, EventArgs e)
{
Response.Redirect(#"~/search.aspx?q=" + Server.UrlEncode(txtSearch.Text));
}
..or use Server.Transfer as suggested by David Kemp.
Note: If you use Request.Query[#"q"] on your search page to get your query, you don't need to use Server.UrlDecode() - it's done for you.
I would:
Add some code to the master page code-behind to detect the source of the POST.
Once I have the source of the POST (e.g. the Search box). I would then pass its query to the Search form.
I used a similar process with having a HTML login form on the master page.
I posted a question and subsequent solution here - check it out:
Form Elements in ASP.NET Master Pages and Content Pages
Once I got my head round it, it seemed a pretty simple and reasonably elegant solution.
The benefit of this is that you have complete control over how the data is sent to the search form. And you don't need to enable transfer of form data to the search form and all that nasty stuff, just create a new GET request to the search page and let it do what it is supposed to do :)
Hope this helps.
NOTE:
You can only have one form with runat="server" on an ASPX page. Additional forms MUST be HTML FORMS.
Because your search form is in the master page, you can probably structure it to contain 2 forms. Place the search form tags with the action set to "search.aspx" outside of the tag that is used by the rest of the site.
<body>
<form action="search.aspx>
<!--search box and submit button-->
</form>
<form runat="server">
<!--rest of page inc placeholder-->
</form>
</body>
If the structure of the page will not enable this, you can set the submit button's PosbackUrl to point to "search.aspx". In this case, "search.aspx" would need to be coded to look in the PreviousPage property for the form data, or use Request.Form to access the input.

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