I am developing a Xamarin Forms app using App Shell.
I found that I had to handle android hardware back button in AppShell.xaml.cs for a ShellContent Page, instead of ShellContent Page.
protected override bool OnBackButtonPressed()
{
//Get currernt shell content and call its method
//like (Shell.Current.Content as MyContentPage).MyMethod();
}
1) How can I obtain current Shell Content Page reference in AppShell.xaml.cs?
2) How can I change current Shell Content Page programmatically without routing ?
Best regards.
It took quite a bit of digging, but I found a public Shell interface that meets this need. If you cast your ShellSection as an IShellSectionController you can use the PresentedPage property get the current Page object. Below is a code snippet, YMMV.
(Shell.Current?.CurrentItem?.CurrentItem as IShellSectionController)?.PresentedPage
I know this is a bit of a late answer, but I noticed that now there is a simpler solution than the solutions presented at the moment:
Shell.Current?.CurrentPage;
In my case,I had bottom tabs with shell and wanted to get values from a tab when on a different tab, I modified #Nick W answer to achieve that using:
(Shell.Current.CurrentItem.Items[0] as IShellSectionController).PresentedPage
where index 0 refers to the first page in the Tabbar collection.
I have a requirement to show a warning popup while navigating from a page to another page . The warning popup should be displayed when the second page is rendered based on the value of a binding(whether the binding has any value (rendered=true)
or is null(rendered=false)).How can i implement it such a way that the popup would be displayed when the second page is rendered itself?
Assuming few things:
1) By page you mean fragment.
2) You are on JDev 12c +.
This is something you may refer to:
execute code on fragment load
This tells you how to register a ControllerClass for your fragment page definition, and get hold of your phase Id.
You may also directly work with regionContext.getRefreshFlag().
However, please note that this code will fire for every request you make from that fragment. So once you close the warning popup, you should set a page-flow parameter which would prevent the popup from opening further.
For 11g releases, this functionality can be achieved by using the invokeAction binding to call a managed bean method, and setting the refresh condition as prepareRender.
Just add a showPopupBehaviour in the Form and make the TrigerType="load"
follow the follow this link : http://prabhat-java.blogspot.ae/2015/10/displaying-popup-on-page-load.html
I have a question about WP8 coding. I have a TextBox for numbers. I want calculate with the number (who has been typed in the box) on another Page. This means, that I don t want to show the number on the next Page, I want to get access to the typed value.
So what is the best way to do this?
Thanks to all answers!
Your question not seemed very clear to me. But if you are asking how to pass data between pages, you can do:
NavigationService.Navigate(new Uri("/destinationPage.xaml?dataName=",value));
In the destination page you can access the data this way:
string targetValue;
If(NavigationContext.QueryString.TryGetValue("dataName", out targetValue))
{
//targetValue will contain value, you can do anything with it
}
DataBinding to controls is different thing:
<TextBox Binding={tBoxValue, Mode = TwoWay} x:name="tbox"/>
Now in code consider presenter is an object, which contains a property tBoxValue:
If you do:
tBox.DataContext = presenter;
You can access the data entered in the TextBox via presenter.tBoxValue;
I am trying to select a link/button inside of a form, that is in a div. the way it was made is that there are two links/buttons of the same id, name etc. however they are in different forms, so the code i wanted to use is:
_myTest.Form(Find.ById("PermissionsForm")).Child(Find.ByClass("saveBtn")).Child(Find.ByText("SAVE"));
any help would be appreciated
I think this is what you need:
var button = _myTest.Form("PermissionsForm").Button(Find.ByClass("saveBtn"));
This will lookup the button having the class 'saveBtn' inside the form 'permissionsform' in your browser instance _myTest.
Have a look at this page to decide if you need to have .Button(..) or .Link(...) based on the html tag that is used in your html.
How about building a regex for the element?
Regex could something like this
Regex elementRe = new Regex("id=LnkOk href="http://stackoverflow.com");
Then you can use your code to Click this link. The Click method can be extended to accept Regex if it is not already doing that.
Let me know how this goes or if you need more info.
Cheers,
DM
I'm looking for the best practice on how to pass data from page to page.
In Page A I have a button that fires off Page B.
On Page B I have 6 textboxes that allow the user to enter information.
When the user is done, the click on a button that brings them back to Page A.
I want to pass that data back to Page A.
I've seen suggestions to:
build XML documents and save to Isolated Storage
use the App class to store information in properties
pass it like a query string
I'm looking for the Best practice. Is there one that Microsoft recommends or one that is generally accepted as the best way?
Thanks
PhoneApplicationService.Current.State["yourparam"] = param
NavigationService.Navigate(new Uri("/view/Page.xaml", UriKind.Relative));
then in other page simply
var k = PhoneApplicationService.Current.State["yourparam"];
Personally I'd store the values entered on Page B in a model(object) that is also accessible to Page A.
Depending on how you're navigating to Page A the second time, one or more of the following may be usful to help understand passing values between pages:
How to pass the image value in one xaml page to another xaml page in windows phone 7?
Passing a complex object to a page while navigating in a WP7 Silverlight application
How to pass an object from a xaml page to another?
How to pass a value between Silverlight pages for WP7?
How do I navigate from one xaml page to another, and pass values?
One thing you can consider is to use MVC: let your App be the controller, store all data in the model, and the pages are just views that contains pure UI logic. In this case your pages are painters and you pass your model object around. This gives nice isolation of business logic and the UI so that you can rev them easily.
BTW, Silverlight and XAML are great tools for MVC so it's a natural match.
There's a couple of things at play here. First of all, if/when the user uses the Back button to return to page A instead of your button, is the information in the text boxes exchanged or not (is Back = Cancel, or is Back = OK?)
That said, if you're using NavigationService.GoBack (which you should be instead of NavigationService.Navigate, because if you use the Navigate call, repeated hits of the back key will cause all kinds of bad UX for your users), then QueryStrings are not an option. Because pages really have no way to reference each other in the WP7 Silverlight nav system, you need to use a 3rd party to hold your data. For that, you can turn to (a) Isolated Storage (slow & heavy, but fail-safe), (b) Use the PhoneApplicationService.State dictionary, or (c) use Global properties of some kind, either hung off of the application object, or using Statics/Singletons...
Remember to watch for Tombstoning behavior when you do this - your page will process the OnNavigatedTo method when (a) you navigate into it in your application (b) you navigate back to it when you complete your work on Page B, or (c) you tombstone your app from that page and return to your application using the Back key.
Sorry I didn't give a more direct answer there - a lot depends on your specific circumstances. In the most general case, I'd strongly consider using the App State Dictionary on the PhoneApplicationService...it is lightweight, easy to use, and survives tombstoning. Just be sure that your keys are as unique as they need to be.
If you create a new Windows Phone project and use the Windows Phone Databound Template you will have most of the work done for you.
What you will want to do is set up the ViewModel to contain all the data for your app. You can serialize and deserialize this data using IsolatedStorage so that it's saved across application sessions and when Tombstoning.
In the template you will notice MailViewModel and ItemViewModel. MainViewModel stores all the data your application needs including an ObservableCollection of ItemViewModel, and ItemViewModel represents the individual data type for your application.
On the DetailsPage.xaml page you'll want to DataBind each textbox to the App.MainViewModel Items. Set the binding to TwoWay if you want the ViewModel to get updated as soon as the user manipulates the data on DetailsPage.xaml. You can optionally set the Binding to OneWay and then have an OK button that writes the changes back to the ViewModel and saves to IsolatedStorage.
Here is an example of what a Binding looks like:
<TextBlock x:Name="ListTitle" Text="{Binding LineOne}" Margin="9,-7,0,0" Style="{StaticResource PhoneTextTitle1Style}"/>
In this case LineOne is a property in ItemViewModel and the page gets this data from the query string when the user selects an item from the MainPage.xaml. The DataContext for the page determs where the databound information comes from.
Here is the snippet where the MainPage passes the selected item from the ViewModel to the DetailsPage.
// Handle selection changed on ListBox
private void MainListBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
// If selected index is -1 (no selection) do nothing
if (MainListBox.SelectedIndex == -1)
return;
// Navigate to the new page
NavigationService.Navigate(new Uri("/DetailsPage.xaml?selectedItem=" + MainListBox.SelectedIndex, UriKind.Relative));
// Reset selected index to -1 (no selection)
MainListBox.SelectedIndex = -1;
}
Here is how the DetailsPage gets the selected item.
protected override void OnNavigatedTo(NavigationEventArgs e)
{
string selectedIndex = "";
if (NavigationContext.QueryString.TryGetValue("selectedItem", out selectedIndex))
{
int index = int.Parse(selectedIndex);
DataContext = App.ViewModel.Items[index];
}
}
Play around with the default template above and ask any additional questions.
The beauty of databinding and the ObservableCollection is that you can just update the data and the UX will reflect those changes immediatley. This is because any changes to the data fires off an event:
public string LineOne
{
get
{
return _lineOne;
}
set
{
if (value != _lineOne)
{
_lineOne = value;
NotifyPropertyChanged("LineOne");
}
}
}
NotifyPropertyChanged() that broadcasts this information to the View.
You can also keep it simple and use PhoneApplicationService.Current.State which is basically a hashtable. You will need to implement your own marshalling to and from isolated storage if you want anything to outlive the app.
Omar's suggestion to use the Windows Phone Databound Template is probably the best idea on this page. It amounts to the same as my suggestion but you will get a better result (more maintainable code) at the cost of a longer steeper learning curve.
I suggest you do it my way and then do it again Omar's way.
as i implemented like this.. Whether its correct or not i dont know..
When u click news list page it should open the news detail page.
I want to pass the selected news item contents from news List-Page to news-details Page.
the News list page contains following method.
protected override void OnNavigatedFrom(System.Windows.Navigation.NavigationEventArgs e)
{
NewsDetailsPage newsDetailPage = (e.Content as NewsDetailsPage);
if (newsDetailPage != null)
newsDetailPage.SelectedNewsItem = SelectedNewsItem; //Contains the news details
base.OnNavigatedFrom(e);
}
In the News details Page. U can access that(SelectedNewsItem) object.
This may or may not be correct.
One option is to use Application.Resources:
Store data:
Application.Current.Resources.Add("NavigationParam", customers);
NavigationService.Navigate(new Uri("/Page2.xaml", UriKind.Relative));
Retrieve data:
var customers = (List<Customer>) Application.Current.Resources["NavigationParam"];
Here's a blog post with describes this in more detail: http://mikaelkoskinen.net/windows-phone-pass-data-between-pages-application-resources/ (author: me)