Recently I came across a problem with an Image Button in an ASP.Net application.
The image file was replaced with the same name in the server when user uploads a new Image,but The image button still showed the old Image even after the page was refreshed.
Did Overcome this issue by adding a query string to the ImageButtom url
Image1.ImageUrl="images/ID102.jpg?"+DateTime.Now.ToString("ddmmyy");
Would like to know if this is the only solution to this??
You should include hours, minutes and seconds to resolve caching problem (also you can add random number but not current datetime))
Your browser was likely caching the old image since it had the same url.
Refresh the page with ctrl+f5 or open up your developer tools and turn off caching in the options.
You can also detect caching by hitting F12 in your browser and looking at the network tab and watching the requests. If you see a "304 Not Modified" it means it's using a cached version.
I always use Google Chrome's Incognito mode to discard any stored cookies/cache while testing my apps.
Related
I have this weird problem my website won't cache the mainsite!
Here is a little overview about what I am trying to do
The first page that is being loaded is the
[DidTheUserLoggedInBefore?.html]
which checks if the user already has logged in or not depending on that result the user will be redirected to
either [LOGIN.html] or [MAINPAGE.HTML]
pretty simple!
But here comes the problem when the user restarts the app in Offline mode the App should redirect immediately to the mainpage (assuming the previous login was a success).
But that doesnt happen at all.
Instead the [DidTheUserLoggedInBefore?.html] from cache was called (which is correct) and starts loading the mainpage which isnt in cache which results in a whitescreen aka my error.
So how do I get my App to cache the Mainpage?
I've tried setting CacheSize to 100, but that didn't changed a thing :(
You can't check if the user has logged in with a .html file... You need some sort of server side language to set a cookie... Anyway this isn't much clear, is your "app" just a webview?
I couldn't let the webview cache more than 2 (simple) webpages...
WebView ignores he offline.manifest.php file too ...
To begin, I should mention that I'm quite new to C# and ASP.NET 4.0. The solution to this problem may be elementary so don't hesitate to ask fundamental questions.
I've inherited an ASP.NET 4.0 application that failed our automated security test because of <page enableViewStateMac="false"> (not my fault). Of course, I turned it on. At that point a very specific pattern of behavior emerged:
1) I can navigate to the application landing page
2) attempting to click on any link leaving the landing page results in a "Validation of viewstate MAC failed..." error.
2a) the exception to this is that clicking on the link that takes me to the landing page (the page I'm already on) works just fine
I should mention that navigation to other ASPs occurs by way of Response.Redirect(...). I can successfully navigate to a page if I enter the url directly into the nav bar (http://dummyhost.com:12345/Enroll.aspx as opposed to http://dummyhost.com:12345/LandingPage.aspx and then clicking on enroll).
In the Page_Init() method of the master page, I'm setting:
Page.ViewStateUserKey = Session.SessionID;
If I comment out this line, I can turn on MAC and the application is perfectly happy. Can anyone illuminate what's going on?
The most likely cause is that some landing-page-specific data is being submitted to the server and persisting through the call to Response.Redirect, so the enrollment page tries to read the landing-page-specific data and fails the request since the data cannot be interpreted correctly.
Instead of using Response.Redirect, consider using ... directly in your markup when you want to generate a simple link. This will cause the browser to make a vanilla HTTP GET request to the specified resource, free of any current-page-specific date.
Alright, I'm using form.target to open content in a new window. However, when I do this and then hit the back button on my browser, I find any entry resulting from a GET is doing another round trip to the server. This is a problem because session variables may have been changed in the interim, so the new GET no longer matches the old one.
I'm using C# and javascript for this web application, if it helps any.
This behavior occurs on IE8, but not on Firefox 10. Is there any way to prevent it in IE?
I solved this problem by adding a semi-random ID as a querystring on the URL.
I also added this to my OnInit event. For some reason explicitly setting the cache settings helps.
Response.AppendHeader("Cache-Control", "private, max-age=600");
Combined, this gave the page uniqueness and enforced the browser caching. This prevented the browser from always retrieving the most recent version of the page when encountering a GET operation in the browsing history.
I'm trying to download file from FTP using javascript, for which I created the following topic:
Is it possible to download file from FTP using Javascript?
From there I learned that I can use window.open('ftp://xyz.org/file.zip'); to download the file. It opens a browser new window, but the window closes immediately.
How I can I force it to stay open?
Actually I do all these in Silverlight application:
Here is the code:
HtmlPage.Window.Eval("window.open('" + url+ "', 'Download', 'height=500,width=800,top=10,left=10');");
I also tried this,
string targetFeatures = "height=500,width=800,top=10,left=10";
HtmlPage.Window.Navigate(new Uri(url), "_blank", targetFeatures);
But both results in same : it opens a window, and closes it immediately. I see it just for fraction of second!
I know this doesn't answer your question, and I'm sure you know all of this. I'm answering more because I don't see this point brought up often. :)
Silverlight has very limited support for client interactions. Javascript is a shim that in my opinion gets overused to try and bypass things that Silverlight was architectured against. It would have been very easy for Microsoft to include FTP support in Silverlight but it was excluded for a reason.
However, Silverlight has great support for webservice interactions. So the recommended way of getting a file would be to call a webservice that would do the FTP transfer for you and then send the contents down to the Silverlight application via the webservice. Possibly even processing it on the webservice side for any business logic etc.
Like I said, I suspect your requirement is to not use a webservice (to pass the bandwith cost onto the user most likely). But it'd be interesting to know more about your business problem instead of your technical problem for the solution you've chosen.
It closes because it triggers file download. You can open two windows - one for message and one to download file, but I thiunk user will know it is downloading...
If I were you, I'd open up a page that has whatever visual/UI stuff you'd want to show the user, and either have a META tag that redirects to the download URL, or has a javascript blurb to fire off said download. That way, your window will stay open, but the download will still start automatically.
to keep it open use
var test = window.open();
test.location = 'ftp://openbsd.org.ar/pub/OpenBSD/2.0/arc/kernels/bsd.ecoff';
and to not open any window use
window.location = 'ftp://openbsd.org.ar/pub/OpenBSD/2.0/arc/kernels/bsd.ecoff';
or make a normal link
Remember that a browser is not meant to "display" (visually anyway) the FTP protocol, and not all browsers will suport it. If you want to allow the user to download something, consider using a normal http:// protocol, and opening a window normally as others have suggested.
If you really need the download to be hosted via FTP, consider your backend ingesting (and caching) the file and return it to the user via http
There is nothing to be parsed on the browser's side, hence it closes. If you want to have the page open, you'll have todo something dirty. Like creating a html (or php) page and serve the content you want the user to see, then with a hidden i-frame which will call the FTP contents.
This way your user will see the content you want them to see, and the file is being downloaded.
I had the exact same problem, Silverlight opening a new window for downloading a file would flash a blank window up briefly and it would disappear again without the file download occurring.
This seemed to happen in IE 8 (not 9 and up) and could be fixed by going into Tools->Internet Options->Security then click Custom level... (for whatever zone your site would be in) and go to Downloads->Automatic prompting for file downloads and make sure this is Enabled (I also have File download enabled below that). This Automatic prompting for file downloads setting seems to be absent from IE 9+.
Another workaround is to not open in a new window, if the target url immediately downloads a file it won't change the current window so there's no difference in UX:
HtmlPage.Window.Navigate(new Uri("\download.ashx?fileid=12345"));
I need to launch a browser, do some work and then make the browser navigate to a URL (in that order).
The first part is of course simple and I have a Process object. I am at a loss as to how to later direct it to the target page?
How do I treat the Process as a browser and make it navigate to the desired page?
Any help, pointers, code snippets appreciated.
Instead of launching the browser & then navigating to the page, just tell the OS that you want to run the URL. Windows will pick the correct browser, and navigate the user to the given URL.
System.Diagnostics.Process.Start("http://www.StackOverflow.com");
If you don't need to do this in production, you could use a testing library such as WatiN to do this:
using WatiN.Core;
//Placeholder page to launch initial browser
IE ie = new IE("http://www.google.com");
DoSomeWork();
//Now navigate to the page you want
ie.GoTo("http://stackoverflow.com");
My first instinct for this question was DDE, but it appears that has been decommissioned in Windows Vista so that is no good. Shame, as it was the only consistent mechanism in Windows for Interprocess Communication (IPC)...oh how I miss Arexx on the Amiga.
Anyhow, I believe the following will work but unfortunately, due to the way it works, it launches Internet Explorer irrespective of the configured browser.
If your application has a Form, then create a WebBrowser control on it. Set this to non-visible as we are only making use of its as a launching device rather than to display the web page.
In code, at the point where you want to show a web page, use the following code:
webBrowser1.DocumentText = "window.open('How to launch a browser and later direct it to a page?', 'BananasAreOhSoYummy');";
What this does is to tell the WebBrowser control, which is just the IE in disguise, to open a new window called 'BananasAreOhSoYummy'. Because we have given the window a name, we can use that line repeatedly, with different URLs, to change the page in that particular browser window. (A new window will be opened if the user has happened to close it.)
I will have a think about an approach that honours the user's default browser choice.
If you don't need the actual instance of IE, you can use the System.Windows.Forms.WebBrowser control.
I think instead of sending the browser a url you could send it javascript that would run and direct the browser to a site.
Not sure if this would work but I see no reason why it wouldn't