Server controls like Image.ImageUrl make this very easy, but trying to achieve the same thing in code behind to an IMG html control is not that straightforward.
For example using an Asp:Image server control and setting ImageUrl property to "~/Images/Test.jpg" works fine no matter what directory i place the code in. (asp.net transforms tilde directory to relative)
How can i do the same in code behind? when i am trying to create an HTML IMG control?
Use Page.ResolveUrl("~/.....");
In the template:
<img id="imgTest" runat="server" />
In the codebehind:
imgTest.Attributes["src"] = this.ResolveUrl("~/yourimage.gif");
Does this solve your problem? Not really sure why you're not using an asp:image control...
Related
I need to display dynamic created html in aspx(server side html);
I tried to use Iframe but it will not displaying anything ; it will not work because of security reasons ;
Is there is any controls that will display html page? Dynamic html have its on css and javascripts so I can’t use html text box controls.
If anyone have solution please help
Thanks
Since your dynamic page has its own CSS & Javascript, I'm assuming it's not written to coexist with its host page. I'm also assuming that when you tried to use the iFrame you just tried to write straight to it from the containing page.
I would suggest moving your code that generates the HTML to a separate ASPX page and referencing that page as the source of your iFrame or rewriting your CSS & Javascript so it will coexist and using a DIV.
Also, it's sort of hard to come up with a workable solution without you showing some of the code you have currently.
Have a look at the
<asp:Literal>
control. There's an example here: Set ASP Literal text with Javascript
-- EDITED 03/05/2012 --
Simple example of an asp.net literal control in action:
.aspx code
<asp:Literal ID="MyLiteral" runat="server" />
.vb code behind
Dim k As String
k = "<table style=""border: 1px solid red;""><tr><td>Cell 1</td></tr><tr><td>Cell 2</td></tr></table>"
MyLiteral.Text = k
If I compile this in VS2008 I get a two row table with a red border in IE.
I found the answer!! Use UFRAME!! It's simple and easy!! uframe.codeplex.com
I have a div element in my HTML. I added a id and runat attributes to the element:
<div id="footer" runat="server">
After rendering, viewing the HTML shows:
<div id="ctl00_footer">
However, I cannot access it from the page's .aspx.cs code:
footer.InnerHtml += "test";
How do I access that element from the C# code?
you can use FindControl("footer"), and cast it to HtmlGenericControl.
HtmlGenericControl footer = (HtmlGenericControl)FindControl("footer")
One of the reasons can be that you don't have designer file for that page. So you can't access element by it's ID.
Just add class with name [your page name].aspx.designer.cs, open it, remove all code, save it, go to your view and click save - designer must generate code of all elements from your view. After this you can access element by ID.
There should be no problem accessing <div id="footer" runat="server"></div> the way you are doing. Strange though, my generated markup keeps the div id unchanged as footer.
Make sure you don't have any compile errors, and that you can access other elements running server-side in the same scope you are trying to access this div.
You need to set the ClientIDMode property of the page or control to Static:
http://msdn.microsoft.com/en-us/library/system.web.ui.control.clientidmode.aspx
This will prevent the "ctl00_" from being appended to the ID which is what is causing you the problem.
I have encountered this problem before. You may have the target div inside another div that does not have the runat="server" attribute. All nested divs should have the runat attribute in order to be able to access the inner elements.
<div id="divContainer" runat="Server">
<div id="yourDiv" runat="Server">
</div>
If you're going to code ASP.NET and you want to access the control from the server-side, you may as well use the provided controls.
Use a Panel instead of a Div. The ASP:Panel control renders as a div in the generated html anyway. The Panel doesn't have a .Text property, but you can add controls to it from code-behind (such as a Label or a LiteralControl.
Is there possibly a chance that the page was copy/pasted when being created? If so, make absolutely sure that all references to the old page are changed to the name of the new page. I've done this before within the code at the top of the ASPX page, as well as the namespace of the designer page.
I had the same problem and found out that due to a "copy" and "paste" my function had a "static" declaration.
Removed it since static functions can't access non-static identifiers and it was fixed.
I have the same issue.
My solution was to have 'ID' instead of 'id' for the div element (i.e. the casing was the reason).
What is the correct way to reference an image in ASP.NET for live deployment on IIS?
The following works in dev and production:
<asp:ImageButton ID="ibnEdit" runat="server" OnClick="ibnEdit_Click" ImageUrl="~/App_Themes/Default/images/one.png" Visible="false" ToolTip="Edit" />
The following doesn't work in either: (why not?)
<img src="~/App_Themes/Default/images/two.gif" />
The following works in dev but not in production:
<img src="../App_Themes/Default/images/two.gif" />
If you want to use a regular img tag with the ~ path, you can just add runat="server" into the tag as an attribute (like regular server controls) and the path will be resolved. e.g:
<img src="~/App_Themes/Default/images/two.gif" runat="server" />
For your second part, is the ../ image reference appearing on more than one page, for example a user control or master page (etc) such that you might be using it at different folder levels...
I use this syntax for access images from master pages
<img src="<%=ResolveUrl("~/Content/Images/error_img.jp")%>" width="350" style="padding-right: 15px; padding-top: 20px;"/>
The ~ will only work on a server control such as <asp:Image> or <asp:ImageButton>. This tells ASP.Net to insert the application path. Sometime that's just "/" but if your application is not the root directory of the website it will include the path it is in. The img tag is just html and it will not be altered by ASP.Net, so the browser gets the path "~/App_Themes/Default/images/two.gif" and doesn't know how to read it.
I don't know why the last example works in dev but not in production. It might has something to do with having the application in the root directory in dev but in a sub directory in production.
This worked for me
$(".selector").attr('src', "Content/themes/base/images/img.png");
The important is that you do not have "/" at the beginning of your new src.
byte[] imageArray = System.IO.File.ReadAllBytes(Server.MapPath("~/Images/Upload_Image.png"));
string base64ImageRepresentation = Convert.ToBase64String(imageArray);
You can look into my answer . I have resolved the issue using C# language.
Why can't I do <img src="C:/localfile.jpg">?
I have a hyperlink that in certain cases I want to change to show a jquery popup, but I'm having a strange problem when doing it on a master page. The following works in a regular page:
hyp1.NavigateUrl = "#notificationPopup";
Which renders as:
<a id="ctl00_hyp1" href="#notificationPopup">Example</a>
This is exactly what I want. The problem is with the exact same code on a hyperlink on the master page it renders as:
<a id="ctl00_hyp1" href="../MasterPages/#notificationPopup">Example</a>
It looks like it might be running the navigateUrl through ResolveClientUrl() or something when I'm setting it on the master page. I've tried swapping the <asp:hyperlink for a <a href runat=server, but the same thing happens.
Any ideas?
There is a note on MSDN Control.ResolveClientUrl method description.
The URL returned by this method is
relative to the folder containing the
source file in which the control is
instantiated. Controls that inherit
this property, such as UserControl and
MasterPage, will return a fully
qualified URL relative to the control.
So the behavior of master page in your exampe is fully predictable (although this is not a very comfortable to work with). So what are the alternatives?
The best one is to set the <a> as a client control (remove runat="server"); should work like a charm even in a master page:
Example
In the case if this control should be server side only: you could just build an URL from your code behind by using UriBuilder class:
UriBuilder newPath = new UriBuilder(Request.Url);
// this will add a #notificationPopup fragment to the current URL
newPath.Fragment = "notificationPopup";
hyp1.HRef = newPath.Uri.ToString();
Create a hidden field on your form and set the value to where you want to navigate / the url of the hyperlink instead of the hyperlinks navigate url. Then call the onclick method of the hyperlink in javascript and set the hyperlink there before the browser does the actual navigation.
<html><head><title></title></head>
<script type="text/javascript">
function navHyperlink(field)
{
field.href = document.getElementById('ctl00_hdnHypNav').value;
return true;
}
</script>
<input type="hidden" id="hdnHypNav" value="test2.html" runat="server"/>
<a href="" onclick="navHyperlink(this);" >click here</a>
</html>
Code behind would be:
hdnHypNav.value = "#notificationPopup";
You could also just try setting the url after the postback with below code, i.e. replace your code behind line with this one but I am not sure if it will work...
ScriptManager.RegisterStartupScript(this,this.GetType(),"SetHyp","$('ctl00_hyp1').href = '#notificationPopup';",True)
I found another way to solve the problem.
hyp1.Attributes.Add("href", "#notificationPopup");
Seeing as the whole reason I replaced my static hyperlink with a runat="server" one was to benefit from automatic resource-based localization, none of these answers served my needs.
My fix was to enclose the hyperlink in a literal:
<asp:Literal ID="lit1" runat="server" meta:resourcekey="lit1">
Example
</asp:Literal>
The downside is if you need to programmatically manipulate the link, it's a bit more annoying:
lit1.Text = String.Format("Example", HttpUtility.HtmlAttributeEncode(url));
I have my UserControls in a ~/Controls folder in my solution:
/Controls/TheControl.ascx
If specify the following:
<a id="theId" runat="server" href="./?pg=1">link text</a>
ASP.Net seems to want to rewrite the path to point to the absolute location. For example, If the control is on site.com/products/fish/cans.aspx the link href will be rewritten to read
<a id="munged_theId" href="../../Controls/?pg=1>link text</a>
Why does Asp.Net rewrite these control paths, and is there an elegant way to fix it?
I just want the anchor control to spit out exactly what I tell it to!!! Is that so hard?
EDIT:
I've basically done what Kelsey suggested. I knew I could do it this way, but I don't like adding markup in my code when I want something relatively simple. At least it solves the problem:
Aspx page:
<asp:PlaceHolder ID="ph" runat="server"></asp:PlaceHolder>
Code-behind:
var anchor = new HtmlGenericControl("a") { InnerText = "Previous" + " " + PageSize) };
anchor.Attributes["href"] = "?pg=" + (CurrentPage - 1);
anchor.Attributes["class"] = "prev button";
ph.Controls.Clear();
ph.Controls.Add(anchor);
As you can see by the amount of code needed for what is essentially supposed to be be a simple and light-weight anchor, it's not the most optimal solution. I know I could use a Literal but I figured this was cleaner as I'm adding more than one anchor.
I would be interesting in knowing WHY ASP.Net takes over and tries to fix my URL, though.
Why do you have runat="server" and no ID defined? Do you need to access it server side? If you remove the runat="server" everything will work as expected.
For more information regardinging how ASP.NET handles paths check out this MSDN article.
Edit: You can get around the problem then by using a Literal control and then outputing the raw <a href... to it.
Eg:
<asp:Literal ID="myLiteral" runat="server" />
myLiteral.Text = "link text";
Then you can set the visible property on the Literal however you want.
I know this is a bit of an old topic, but I was running into this problem as well and in the end went with a similar solution, but was able to save a few lines of code by doing this in the ascx:
<anchor id="myAnchor" runat="server" href="xxx">link text</anchor>
Then in the code behind, I referenced it using an HtmlGenericControl and can then do this:
myAnchor.TagName = "a";
// other properties set as needed
Anyway, I thought I'd post in case anyone else stumbles in here with the same issue.
Best bet is to make everything app root relative using the magic ~/ lead-in to the url. That tends to keep stuff straight.
There isn't a great answer to your question. ASP.NET is going to treat a relative path in a UserControl as relative to the path of the user control.
What you can do is in the code behind for your user control, set the HRef property of your anchor tag based on the Request.Path property. Then you can create URLs relative to the page.
Alternative is to use a literal like Kelsey was suggestion, or I would just try and map everything app relative with ~/ like Wyatt suggested.
Even a literal doesn't work using ICallBackEventHandler and RenderControl at least... I ended up hacking the tag back client-side :/ e.g in JQuery:
$('#munged_theId').attr('href', './?pg=1');