I am developing a UWP windows 10 application and I want to have a page that is only shown at the start of launching application first time. It should not be shown when the app is opened second time in a system.
I have searched online about it but couldn't find any thing about it.
I know that my answer can be refined more, but i have done with spending 2 minutes and its working for me. I have added a page loaded event in my StartPage.xaml.cs file and added the following code inside it.
if (localSettings.Values["IsFirstTime"] == null)
{
localSettings.Values["IsFirstTime"] = true;
}
if ((bool)localSettings.Values["IsFirstTime"])
{
localSettings.Values["IsFirstTime"] = false;
this.Frame.Navigate(typeof(MainPage));
}
Make sure you make a localSettings object at class level (of type ApplicationDataContainer). Now inside App.xaml.cs, I have added global variable for local settings as follow.
Windows.Storage.ApplicationDataContainer localSettings = Windows.Storage.ApplicationData.Current.LocalSettings;
Inside app.xaml.cs file come to the if condition showing rootFrame.Content == null and replace every thing inside it with the following code.
object value = localSettings.Values["IsFirstTime"];
if (localSettings.Values["IsFirstTime"] != null)
{
if ((bool)value)
{
rootFrame.Navigate(typeof(StartPage), e.Arguments);
localSettings.Values["IsFirstTime"] = false;
}
else
{
rootFrame.Navigate(typeof(MainPage), e.Arguments);
}
}
else
{
rootFrame.Navigate(typeof(StartPage), e.Arguments);
localSettings.Values["IsFirstTime"] = false;
}
I have tried it by uninstalling my app and run again to see if start page is shown (and it shows up). Second time when i open, MainPage is shown).
In App.xaml.cs look for the OnLaunched handler. There are these lines of code for "switching" pages:
if (rootFrame.Content == null)
{
rootFrame.Navigate(typeof(MainPage), e.Arguments);
}
As #Romasz suggested in comments, you can add here additional logic with local (or better - roaming) storage to check whether app is launched for the first time:
var roamingSettings = ApplicationData.Current.RoamingSettings;
if (roamingSettings.Values.ContainsKey("NotFirstTimeLaunch"))
{
rootFrame.Navigate(typeof(MainPage), e.Arguments);
} else
{
roamingSettings.Values["NotFirstTimeLaunch"] = true;
rootFrame.Navigate(typeof(FirstLaunchPage), e.Arguments);
}
Related
I am trying to develop an app using Xamarin.Forms. At a certain point I am trying to have multiple switches that are grouped. This is to say that when one switch is toggled, every other switch needs to be untoggled and, at the same time, there needs to be at least one switch always toggled. This is to say that tapping on a switch that is already toggled should not change anything.T
Now my problem is that Xamarin.forms Toggled event for switches can be fired from the UI, but is also fired programmatically. I thought I had found a way around this problem, but still by doing:
-If the switch was turned on, turn off all others and do application stuff.
-else if a switch was turned off, check if there are any others that are on. If not, turn the switch back on. If yes, do nothing.
A sample code for two switches could be:
private void OnFirstToggled(object sender, EventArgs args)
{
if(FirstSwitch.isToggled)
{
//Application stuff.
SecondSwitch.isToggled = false;
}
else if (!SecondSwitch.isToggled)
{
FirstSwitch.isToggled = true;
}
}
private void OnSecondToggled(object sender, EventArgs args)
{
if(SecondSwitch.isToggled)
{
//Application stuff.
FirstSwitch.isToggled = false;
}
else if (!FirstSwitch.isToggled)
{
SecondSwitch.isToggled = true;
}
}
This solution results in an infinite loop when an already toggled switch is tapped. In fact, the isToggled property of the switch alternates between true and false infinitely. However when debugging the other event never seems to be fired (or at least my debugger does not see it). This is why I don't understand where the isToggled property is changed after that first tap.
I know this is probably a very simple issue, but I cannot seem to find the solution somewhere online. Can anyone see the problem or recommend a better, common way to implement this?
I write a simple solution to you to always keep one Switch open from a Switch group.
Let's first add three switch for test, make sure these Switch will fire the same event of Toggled:
<StackLayout>
<!-- Place new controls here -->
<Switch Toggled="Switch_Toggled" x:Name="FirstSwitch"/>
<Switch Toggled="Switch_Toggled" x:Name="SecondSwitch"/>
<Switch Toggled="Switch_Toggled" x:Name="ThirdSwitch"/>
</StackLayout>
In the code behind, I add those Switches into a list, and loop them in Switch_Toggled event to open/close the Switches:
public partial class MainPage : ContentPage
{
List<Switch> switchList;// To store all your Switches
bool isLooping; //To make sure the Switch_Toggled metod not fired a second time during one toogle event
public MainPage()
{
InitializeComponent();
switchList = new List<Switch>();
switchList.Add(FirstSwitch);
switchList.Add(SecondSwitch);
switchList.Add(ThirdSwitch);
isLooping = false;
}
private void Switch_Toggled(object sender, ToggledEventArgs e)
{
//To make sure the Switch_Toggled metod not fired a second time during one toogle event
if (isLooping == true)
{
return;
}
isLooping = true;
Switch clickSwitch = sender as Switch;
clickSwitch.IsToggled = true;
foreach (var tempSwitch in switchList)
{
if (tempSwitch != clickSwitch)
{
if (tempSwitch.IsToggled == true)
{
tempSwitch.IsToggled = false;
}
}
}
isLooping = false;
}
}
You can try this solution and feel free to ask me any question if you don't understand.
Your problem are the two else blocks. Take in account that you're toggling it on anyway.
I'm developing a Visual Studio extension in which one of the implemented commands needs to be available only when the active document is a text document (like e.g. the Visual Studio's "Toggle Bookmark" does). The problem is that I can't figure out how to tell when that's the case.
Right now I have a half working solution. In the package's Initialize method I subscribe to DTE's WindowActivated event, and then whenever a window is activated I check if the window DocumentData property is of type TextDocument:
protected override void Initialize()
{
base.Initialize();
var dte = Package.GetGlobalService(typeof(EnvDTE.DTE)) as EnvDTE.DTE;
dte.Events.WindowEvents.WindowActivated += WindowEventsOnWindowActivated;
//More initialization here...
}
//This is checked from command's BeforeQueryStatus
public bool ActiveDocumentIsText { get; private set; } = false;
private void WindowEventsOnWindowActivated(Window gotFocus, Window lostFocus)
{
if (gotFocus.Kind != "Document")
return; //It's not a document (e.g. it's a tool window)
TextDocument textDoc = gotFocus.DocumentData as TextDocument;
ActiveDocumentIsText = textDoc != null;
}
The problem with this approach is that 1) Window.DocumentData is documented as ".NET Framework internal use only", and 2) this gives a false positive when a document that has both a code view and a design view (e.g. a .visxmanifest file) is open in design mode.
I have tried to use IVsTextManager.GetActiveView as well, but this is returning the last active text view opened - so if I open a .txt file and then a .png file, it returns data for the .txt file even if it's not the active document anymore.
So, how do I check if the active document is a text document, or the code view of a document that can have a designer... and if possible, not using "undocumented" classes/members?
UPDATE: I found a slightly better solution. Inside the window activated handler:
ActiveDocumentIsText = gotFocus.Document.Object("TextDocument") != null;
At least this one is properly documented, but I still have the problem of false positives with designers.
I finally got it. It's somewhat tricky, but it works and is 100% "legal". Here's the recipe:
1- Make the package class implement IVsRunningDocTableEvents. Make all the methods just return VSConstants.S_OK;
2- Add the following field and the following auxiliary method to the package class:
private IVsRunningDocumentTable runningDocumentTable;
private bool DocIsOpenInLogicalView(string path, Guid logicalView, out IVsWindowFrame windowFrame)
{
return VsShellUtilities.IsDocumentOpen(
this,
path,
VSConstants.LOGVIEWID_TextView,
out var dummyHierarchy2, out var dummyItemId2,
out windowFrame);
}
3- Add the following to the Initialize method of the package class:
runningDocumentTable = GetService(typeof(SVsRunningDocumentTable)) as IVsRunningDocumentTable;
runningDocumentTable.AdviseRunningDocTableEvents(this, out var dummyCookie);
4- Don't blink, here comes the magic! Implement the IVsRunningDocTableEvents.OnBeforeDocumentWindowShow method as follows:
public int OnBeforeDocumentWindowShow(uint docCookie, int fFirstShow, IVsWindowFrame pFrame)
{
runningDocumentTable.GetDocumentInfo(docCookie,
out var dummyFlags, out var dummyReadLocks, out var dummyEditLocks,
out string path,
out var dummyHierarchy, out var dummyItemId, out var dummyData);
IVsWindowFrame windowFrameForTextView;
var docIsOpenInTextView =
DocIsOpenInLogicalView(path, VSConstants.LOGVIEWID_Code, out windowFrameForTextView) ||
DocIsOpenInLogicalView(path, VSConstants.LOGVIEWID_TextView, out windowFrameForTextView);
//Is the document open in the code/text view,
//AND the window for that view is the one that has been just activated?
ActiveDocumentIsText = docIsOpenInTextView && pFrame == logicalViewWindowFrame;
return VSConstants.S_OK;
}
I am trying to get dataView.collapseAllGroups() to work with SlickGrid.
The post In SlickGrid, how do I collapse grouping via javascript says to just use collapseAllGroups() but it doesn't seem to work.
Even when going to the current demo page http://mleibman.github.io/SlickGrid/examples/example5-collapsing.html and typing dataView.collapseAllGroups() into the console, it doesn't seem to do anything. Is there something else that I need to do to refresh the grid?
Edit
I was trying to get the Grid to display a tree where the groups are collapsed by default. Although I cannot get CollapseAllGroups() to work, I was able to do a hack by adding "if (item._collapsed == null) item._collapsed = true;" to myFilter function that is in the example above.
This is a rough worksound but it does the job for now until I find the real solution:
function myFilter(item) {
// Added this line:
if (item._collapsed == null) item._collapsed = true;
if (item.parent != null) {
var parent = gridData[item.parent];
while (parent) {
if (parent._collapsed) {
return false;
}
parent = gridData[parent.parent];
}
}
return true;
}
That particular example demonstrates how to implement hierarchies using custom formatters and a filter. It does NOT use the DataView's grouping feature, so the collapseAllGroups() call has no effect.
I'm making a windows phone app which displays where the closest campus shuttles are (among other things). Windows Phone requires apps to allow the users to turn off location services within the app.
So, I added a toggle for it on a settings page, but it doesn't seem to do anything.
Here's the viewmodel where I declared the geocoordinatewatcher.
public MainViewModel()
{
geoWatcher = new GeoCoordinateWatcher();
if (geoWatcher.TryStart(false, TimeSpan.FromSeconds(30) )==false )
{ MessageBox.Show("The location services are disabled for this app. We can't detect the nearby stops. To turn location services back on, go to the settings page.", "Warning", MessageBoxButton.OK); }
}
private GeoCoordinateWatcher geoWatcher;
public GeoCoordinateWatcher GeoWatcher
{
get
{
return geoWatcher;
}
set
{
if (geoWatcher != value)
{
geoWatcher = value;
NotifyPropertyChanged("GeoWatcher");
}
if(geoWatcher.Status== GeoPositionStatus.Disabled)
{
geoWatcher.Stop();
}
}
}
and here's the bulk of the settings page
public SettingsPage()
{
InitializeComponent();
if (App.ViewModel.GeoWatcher.Status == GeoPositionStatus.Ready)
{
locToggle.IsChecked = true;
locToggle.Content = "On";
}
else
{
locToggle.IsChecked = false;
locToggle.Content = "Off";
}
}
private void toggleChecked(object sender, RoutedEventArgs e)
{
locToggle.Content = "On";
App.ViewModel.GeoWatcher.Start();
MessageBox.Show("this is the status " + App.ViewModel.GeoWatcher.Status.ToString(), "Info", MessageBoxButton.OK); //for debugging
}
private void toggleUnchecked(object sender, RoutedEventArgs e)
{
locToggle.Content = "Off";
App.ViewModel.GeoWatcher.Stop();
MessageBox.Show("this is the status " + App.ViewModel.GeoWatcher.Status.ToString(), "Info", MessageBoxButton.OK); //for debugging
}
When i turn the toggle off and click away from the Settings page, and go back to it, the toggle is re-enabled again.
I tried putting in a message box on the functions to debug but the status always says "Ready" and my app still uses the location services, even when I turn the toggle to "off".
Is there something I should be adding to the code so that the toggle will properly make my app stop using location services across my app if it's disabled on the settings page? Or should I be checking something else besides GeoPositionStatus? I couldn't figure out a way to make my app actually change the location services permissions or PositionStatus.
I looked at this page here, but am still confused since I followed the example at the bottom of the page, to no avail. I searched StackOverflow but I couldn't seem to find a similar question with WP. I also posted this on the AppHub forums though.
Thanks!
In your MainViewModel you need to check if they have allowed location services before you use the geocoordinatewatcher.
if(settings.LocationAllowed)
{all your code for using location}
You should probably take into account a few factors/points, most of which, you have. Anyway, you might find these helpful.
Your application settings toggle should only show when the location service is switched on on the device
GeoPositionStatus is just an Enum which contains the types of statuses.
StatusChanged is the event which is to be handled to check for changes in the device settings. See this.
You cannot change the device settings from the application.
Add event handlers before you call start on the watcher.
I need to navigate to a certain page the first time my app is run, to gather login details etc. I'm using IsloatedStorageSettings to save a value to determine if this is the first run of the app or not, which works fine.
My problem is actually navigating to my 'first run' page when the app is run for the first time, using NavigationService, it seems NavigationService is not created at this point so is still null. When is NavigationService created or how can I work around this?
My code (in the constructor of my main page:
if ((bool)settings["firstRun"])
{
if (NavigationService != null)
{
NavigationService.Navigate(new Uri("/FirstRun.xaml", UriKind.Relative));
}
else
{
MessageBox.Show("Navigation service must be null?"); //always prompts
}
}
else
{
InitializeComponent();
}
Peter Torr has a great blog post on the ins and outs of redirecting for the initial navigation, though for user login I'd suggest that you either use a full screen popup or have a login control on your "normal" start page and toggle visibility based on your first run condition.
Add in class
private bool m_onNavigatedToCalled = false;
In ctor
this.LayoutUpdated += new EventHandler(MainPage_LayoutUpdated);
Then in code
void MainPage_LayoutUpdated(object sender, EventArgs e)
{
if (m_onNavigatedToCalled)
{
m_onNavigatedToCalled = false;
Dispatcher.BeginInvoke(() =>
{
if (NavigationService != null)
{
MessageBox.Show("Navigation not null?"); //always prompts
}
else
{
MessageBox.Show("Navigation service must be null?");
}
//StartApp(); do all stuff here to keep the ctor lightweight
}
);
}
}