I've something that I can't get myself understand. I'm making an app with databound template. I put a textbox on mainpage and a button. when i type something in textbox and press on button it navigates to the listing page and that content comes from web and then if i press on back button and make a new search the results from previous search stays there. how can i reset/clear or disable cache of that page?
It would be helpful if you could post your XAML and code-behind, but I will attempt to make a jab at an answer. Where are you referencing the call to get the data from the web? If it is in the constructor of the page, then that is why the previous search stays there. What is probably happening is the first search constructs the secondary page, does your web call, and binds your data to the page. Then when you press the back button, and click it again, the page is already constructed, so it uses the same data.
It is probably wise to call your web service in the OnNavigatedTo override method. From the first page, you can pass parameters to your secondary page (i.e., pass the search term, then pass the search term into your web service).
Here is an example of passing parameters between pages: http://developer.nokia.com/Community/Wiki/Passing_parameters_while_navigating_between_pages_on_Windows_Phone
Also, make sure your Data Context for the second page is appropriately set each time the page is navigated to, since you have a data bound application.
Without code, I can't really help other than giving these things to think about.
Related
Currently I'm in say Page A. The URL is http://localhost:22507/PageA.aspx. From there select a dropdown value. Now the same page shows some extra data and an edit button along with the dropdown. Page URL is still http://localhost:22507/PageA.aspx. When I click the Edit button its redirected to another page Page B. And the present URL is http://localhost:22507/PageB.aspx?qstr=6EysKHDt1+a/m8SQcruQOCVgWF+9+PCfmydyeX5wbKU=
While clicking the Back button in the Page B, it directly goes to the first state. ie, I've to again select the drop down, click edit etc.
How can I go back to the just previous state(Page A with data and Edit button) after clicking Back button?
Now I use Response.Redirect("PageA.aspx", false); for redirecting
When changing the selected list item, use pushState to update the browser address bar and history to record the change of state. E.g instead of the address bar still displaying /PageA.aspx, it could instead show /PageA.aspx?selected=1.
If you then use the back button from PageB.aspx?qstr=6EysKHDt1+a/m8SQcruQOCVgWF+9+PCfmydyeX5wbKU=, pressing back will return you to PageA.aspx?selected=1. You can then parse the query string to determine the correct state to display.
Mozilla provides documentation on pushState here: https://developer.mozilla.org/en-US/docs/Web/API/History_API.
Note that for older browsers there are some compatibility issues. A clunky old method that would work would be to reload the page with a query string when the dropdown is changed, allowing the back button to work in much the same way. An alternative that avoids reloading the page may be to update a cookie with a flag indicating the state. On loading the page, check for the cookie and flag. However, then you would need to consider expiry of the cookie (ie what if they didn't press back but instead navigated to pageA again through some other means, would loading the saved state still be acceptable?).
I am migrating my Windows Phone 8 App to Windows 8.1 App and I have created a Page with blank page template. In that there are some Items like TextBlock,ComboBox and TextBox. Now, there is an item LocationTextBlock with border around it. When I click on it, it navigates to a new Page LocationPage, where I need to select location and save that object and navigate using Frame.GoBack() method. Now the issue, when I navigate back, I get the object of LocationData but the LocationTextBlock which was created previously is showing null, so I can't populate Location in that TextBlock.
Questions
Is this issue occurring due to Blank Page Template ?
Can it be solved using NavigationHelper Class?
Will using Basic Page Template resolve this issue?
Please suggest with some code or description, whether it can be done using Blank Page template as I have added many lines of code inside it.
It can be done with Blank Page template (although using NavigationHelper would be the prefered way).
What you have to do is set NavigationCacheMode to Enabled in your Page's Constructor:
this.NavigationCacheMode = NavigationCacheMode.Enabled;
This way the Page with all the properties in it is cached. So when you navigate back you get back the state in which the Page was when you navigated from it. However, if you navigate to this page not through backnavigation, you'll still get back the saved state, which you don't want. The solution is to clean up all the resources (initializing the needed variables, setting UI elements to default value etc.) in the OnNavigatedTo(NavigationEventArgs e) method if (e.NavigationMode != NavigationMode.Back). Don't know if it's the best approach, but it'll work.
EDIT:
You could even use a Flyout or a ContentDialog instead of your LocationPage, so you don't need to navigate from the page, thus not needing to cache/save the page.
I'm very very new to asp.net, and in my tour of its features I found that if you use Server.Transfer instead of Response.Redirect then, among other things, you could preserve the URL of the original page. I created two test pages.
The first has a textbox and a button. When you click the button, the contents of the textbox are saved in the Session variable and Server.Transfer is used to load the second page. On this page there's a button and a label. When you click the button, the label gets populated with what was saved in the session variable.
The issue is, when I click the button on the second page and the label is altered, the URL changes to that of the second page. This seems a bit to defeat the purpose, so how do I go about preserving the URL?
Clicking the button on the second page is causing a postback and the server is showing the URL of the page you are posting back to (the second page). In effect, you have done a Response.Redirect to yourself.
I am curious as to why you want to have two separate .aspx pages behave as if they are only one. One of the major drawbacks of using Server.Transfer is the confusion it causes the user when they think they are on a new page, but the browser says otherwise; especially in bookmarking scenarios.
If you want the logic to reside in a single .aspx page, but act as two separate logical units, then I suggest you use ASP.NET Panel controls that show/hide the logic as needed and the page's code-behind can react to the necessary events (i.e. button clicks) all in one page and the URL will be the same the entire time.
So, I have a page that looks like the following:
alt text http://img704.imageshack.us/img704/5973/croppercapture3.png
This is my basic messaging inbox. I have 2 pages right now, Inbox and Sent (there will eventually be others). These both share the same View, and just have 2 different actions to populate the appropriate data.
The elements on the right-hand side (the message list) is a partial view which has its data populated based on my two controller actions Inbox(int? page) and Sent(int? Page).
So, I have one view "MessageView" and one partial view "MessageList" shared between Inbox/Sent.
However, I now have to get those arrow buttons ("<" ">") working using Ajax. I know how to use jQueries ajax calls well enough, and I know how to render the result of the action call (which returns a partial view).
The problem comes from the fact that the javascript that makes these pagination ajax calls needs to know two things:
What the current page is (whether it be /messages/inbox or /messages/sent)
What the current page is (specified in the query string, ie /messages/inbox?page=2).
Without knowing which page I'm on (Inbox or Sent), it wont know which url to make the ajax call on. Should it make the postback to /messages/inbox or to /messages/sent?
If I wasn't making these messages load with Ajax it would be as simple as loading the appropriate url into the link tags for the "<" and the ">" buttons. But I can't, because part of my requirements states that it must load the messages below without visibly refreshing to a new page.
In JavaScript you can check window.location.pathname to see the pathname section of the current’s page’s URL.
window.location.search gives you the query string.
When the user clicks the Inbox or Sent buttons, you need to rewrite the URLs in your arrows so that they point to the right place.
Ok so while back I asked question Beginner ASP.net question handling url link
I wanted to handle case like this www.blah.com/blah.aspx?day=12&flow=true
I got my answer string r_flag = Request.QueryString["day"];
Then what I did is placed a code in Page_Load()
that basically takes these parameters and if they are not NULL, meaning that they were part of URL.
I filter results based on these parameters.
It works GREAT, happy times.... Except it does not work anymore once you try to go to the link using some other filter.
I have drop down box that allows you to select filters.
I have a button that once clicked should update these selections.
The problem is that Page_Load is called prior to Button_Clicked function and therefore I stay on the same page.
Any ideas how to handle this case.
Once again in case above was confusing.
So I can control behavior of my website by using URL, which I parse in Page_Load()
and using controls that are on the page.
If there is no query in URL it works great (controls) if there is it overrides controls.
Essentially I am trying to find a way how to ignore parsing of url when requests comes from clicking Generate button on the page.
Maybe you can put your querystring parsing code into IsPostBack control if Generate button is the control that only postbacks at your page.
if (!IsPostBack)
{
string r_flag = Request.QueryString["day"];
}
As an alternative way, at client side you can set a hidden field whenever user clicks the Generate button, then you can get it's value to determine if the user clicked the Generate button and then put your logic there.