I recently created an interface with MVVM making sure there was no code behind. Our development team in India reused that interface with some modifications. When I went to use the new UI I found that these modifications seemed to break some of the bindings I had made between the view and viewmodel. I then found this new code below in the view. I have only included part of the code. You can see that the viewmodel is referenced multiple times in the view. I though it was a highly discouraged. I know that having a setter to the viewmodel in the view is something they are always doing with their Prism implementation, but I have never seen actual calls to the viewmodel from the view before. I don't want to bring this up with their supervisor unless I am sure of my position with regards to good coding practice.
[Import]
public ProfileLimitsViewModel ViewModel
{
get
{
return DataContext as ProfileLimitsViewModel;
}
set
{
DataContext = value;
_performSelection = true;
ViewModel.OnSelectedProfilesChanged -= setSelection;
ViewModel.OnSelectedProfilesChanged += setSelection;
}
}
/// <summary>
/// On Profile selection changed in UI
/// </summary>
private void ProfileList_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
try
{
int count = 0;
ViewModel.SelectedProfiles.Clear();
//if multiple profile is selected
if (ProfileList.SelectedItems.Count > 0)
{
foreach (var profile in ProfileList.SelectedItems)
{
ViewModel.SelectedProfiles.Add((profile as ProfileNS).ProfileID);
//the profile that is selected
if (count++ == 0)
ViewModel.SelectedProfile = profile as ProfileNS;
}
}
if (_performSelection)
{
ViewModel.SelectedFormationId = ViewModel.SelectedProfile.Layers[0].BedId;
ViewModel.ProfileSelectionChanged();
}
}
catch(Exception ex)
{
Diagnostics.LogHandledException(ex);
}
}
/// <summary>
/// on closed
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void ProfileEditor_Closed(object sender, RoutedEventArgs e)
{
//Event to update ProfileEditor checkbox in ContextualTab
ServiceLocator.Current.GetInstance<IEventAggregatorService>().Publish
<ProfileEditorSelectedEvent, MCWDEditorMode>(MCWDEditorMode.Close);
ViewModel.ModuleService.UpdateMcwdEditorViewModelsHash(ViewModel.WellLandingId, null);
}
/// <summary>
/// On formation selection changed in UI
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void ProfileLayersDataGrid_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
try
{
if (e.AddedItems != null && e.AddedItems.Count > 0 && _performSelection)
ViewModel.FormationSelectionChanged(e.AddedItems[0]);
}
catch (Exception ex)
{
Diagnostics.LogHandledException(ex);
}
}
An event handler in C# is a sure sign you are not doing MVVM properly. I'm looking at you, ProfileList_SelectionChange. Reference for you/your boss: https://msdn.microsoft.com/en-us/library/hh848246.aspx Prism only gives you the tools to do MVVM properly; it does not prevent you from doing things in WinForms style.
Todd Sprang is right, at least partly. There may be legit reasons to use EventHandlers, but the one pointed out by Todd (ProfileList_SelectionChange) is definitively not belonging there, neither is RoutedEventArgs, as they are both defined in the Presentation.dll.
There are pretty easy ways to enforce this, by splitting your MVVM layers into multiple assemblies.
MyApp.ViewModels.dll assembly and put only ViewModels there
Put your view related stuff in a MyApp.UI.dll assembly (Views)
Application related goes into MyApp.Desktop.dll or MyApp.WinPhone.dll etc. Plattform dependend stuff, WPF, XAML, Silverlight, ASP.NET)
MyViewModels.dll should never have a reference to UI/Desktop assembly and NEVER reference Presentation.dll. If a developer needs to use anything from Presentation.dll you automatically know, it violates MVVM, because you will have a reference to Platform or View specific type in your code
Related
With the new MRTK2 I'm looking to disable spatial mapping after we are done using it to place GameObjects. I'm stuck on what exactly to call in the namespace or on the service to do this at run time.
I've tried: MixedRealityToolkit.SpatialAwarenessSystem.SuspendObservers();
This has no effect. I could disable the entire "Spatial Awareness System" GameObject, but this would be a hack.
What I need is the proper call that would disable the system entirely so that resources are freed up when it is no longer useful?
Additionally, a little insight into how we are to access the service system correctly would be of great help.
You can use the following code to disable/enable the spatial awareness system:
if (disable)
{
// disable
MixedRealityToolkit.SpatialAwarenessSystem.Disable();
}
else
{
// enable
MixedRealityToolkit.SpatialAwarenessSystem.Enable()
}
You can use the following code to enable/disable just the visualization but keep the colliders on:
foreach(var observer in MixedRealityToolkit.SpatialAwarenessSystem.GetObservers())
{
var meshObserver = observer as IMixedRealitySpatialAwarenessMeshObserver;
if (meshObserver != null)
{
meshObserver.DisplayOption = SpatialAwarenessMeshDisplayOptions.None;
}
}
You can read more documentation about the Spatial Awareness system in MRTK on the mrtk github.io site at Spatial Awareness System Usage guide
I would have expected the SuspendObservers() method to result in no new meshes being displayed. Do you see the meshes changing after suspending?
It is by design for the meshes to remain visible until the application explicitly sets their visibility to None via the IMixedRealitySpatialAwarenessMeshObserver.DisplayOption property.
Thanks!
Note the previous answer doesn't work due to recent changes to the MRTK framework.
Link for SpatialAwareness DataProvidershere
Code pasted from said link:
IMixedRealityDataProviderAccess dataProviderAccess =
CoreServices.SpatialAwarenessSystem as IMixedRealityDataProviderAccess;
if (dataProviderAccess != null)
{
IReadOnlyList<IMixedRealitySpatialAwarenessMeshObserver> observers =
dataProviderAccess.GetDataProviders<IMixedRealitySpatialAwarenessMeshObserver>();
foreach (IMixedRealitySpatialAwarenessMeshObserver observer in observers)
{
// Set the mesh to use the occlusion material
observer.DisplayOption = SpatialMeshDisplayOptions.Occlusion;
}
}
[AddComponentMenu("Scripts/MRTK/Examples/ClearSpatialObservations")]
public class ClearSpatialObservations : MonoBehaviour
{
/// <summary>
/// Indicates whether observations are to be cleared (true) or if the observer is to be resumed (false).
/// </summary>
private bool clearObservations = true;
/// <summary>
/// Toggles the state of the observers.
/// </summary>
public void ToggleObservers()
{
var spatialAwarenessSystem = CoreServices.SpatialAwarenessSystem;
if (spatialAwarenessSystem != null)
{
if (clearObservations)
{
spatialAwarenessSystem.SuspendObservers();
spatialAwarenessSystem.ClearObservations();
clearObservations = false;
}
else
{
spatialAwarenessSystem.ResumeObservers();
clearObservations = true;
}
}
}
}
I am currently learning C# in UWP environment. I have a test app which is having a bit of the problem as described in Splitview with frame and navigating to another page, back button does not work.
But the my code is a little different from the above page.
My App.xaml.cs has the following code:
namespace Testing
{
/// <summary>
/// Provides application-specific behavior to supplement the default Application class.
/// </summary>
sealed partial class App : Application
{
/// <summary>
/// Initializes the singleton application object. This is the first line of authored code
/// executed, and as such is the logical equivalent of main() or WinMain().
/// </summary>
public App()
{
this.InitializeComponent();
this.Suspending += OnSuspending;
//NavigationCacheMode.Enabled;
}
/// <summary>
/// Invoked when the application is launched normally by the end user. Other entry points
/// will be used such as when the application is launched to open a specific file.
/// </summary>
/// <param name="e">Details about the launch request and process.</param>
protected override void OnLaunched(LaunchActivatedEventArgs e)
{
#if DEBUG
if (System.Diagnostics.Debugger.IsAttached)
{
this.DebugSettings.EnableFrameRateCounter = true;
}
#endif
Frame rootFrame = Window.Current.Content as Frame;
// Do not repeat app initialization when the Window already has content,
// just ensure that the window is active
if (rootFrame == null)
{
// Create a Frame to act as the navigation context and navigate to the first page
rootFrame = new Frame();
rootFrame.NavigationFailed += OnNavigationFailed;
if (e.PreviousExecutionState == ApplicationExecutionState.Terminated)
{
//TODO: Load state from previously suspended application
}
// Place the frame in the current Window
//--------------------------------------------------------------------
//Window.Current.Content = new SplitShellPage(rootFrame);
//--------------------------------------------------------------------
Window.Current.Content = rootFrame;
}
if (e.PrelaunchActivated == false)
{
if (rootFrame.Content == null)
{
// When the navigation stack isn't restored navigate to the first page,
// configuring the new page by passing required information as a navigation
// parameter
rootFrame.Navigate(typeof(MainPage), e.Arguments);
}
Windows.UI.Core.SystemNavigationManager.GetForCurrentView().BackRequested += App_BackRequested;
// Ensure the current window is active
Window.Current.Activate();
}
}
/// <summary>
/// Invoked when Navigation to a certain page fails
/// </summary>
/// <param name="sender">The Frame which failed navigation</param>
/// <param name="e">Details about the navigation failure</param>
void OnNavigationFailed(object sender, NavigationFailedEventArgs e)
{
throw new Exception("Failed to load Page " + e.SourcePageType.FullName);
}
/// <summary>
/// Invoked when application execution is being suspended. Application state is saved
/// without knowing whether the application will be terminated or resumed with the contents
/// of memory still intact.
/// </summary>
/// <param name="sender">The source of the suspend request.</param>
/// <param name="e">Details about the suspend request.</param>
private void OnSuspending(object sender, SuspendingEventArgs e)
{
var deferral = e.SuspendingOperation.GetDeferral();
//TODO: Save application state and stop any background activity
deferral.Complete();
}
private void App_BackRequested(object sender, Windows.UI.Core.BackRequestedEventArgs e)
{
Frame rootFrame = Window.Current.Content as Frame;
if (rootFrame == null)
return;
// Navigate back if possible, and if the event has not
// already been handled .
if (rootFrame.CanGoBack && e.Handled == false)
{
e.Handled = true;
rootFrame.GoBack();
}
}
}
}
If I use Window.Current.Content = new SplitShellPage(rootFrame); as in place of Window.Current.Content = rootFrame; the SplitView works but the back button does not work. If I use the second line then SplitView doesn't work but back navigation works.
I even tried setting my launch page to SplitView page as rootFrame.Navigate(typeof(SplitShellPage), e.Arguments); but that causes the application to stop at runtime and the application doesn't start.
The other pages with code are as:
SplitShellPage.xaml.cs
namespace Testing.Pages
{
/// <summary>
/// An empty page that can be used on its own or navigated to within a Frame.
/// </summary>
public sealed partial class SplitShellPage : Page
{
public SplitShellPage(Frame frame)
{
this.InitializeComponent();
NavigationCacheMode = NavigationCacheMode.Enabled;
shell_splitview.Content = frame;
(shell_splitview.Content as Frame).Navigate(typeof(MainPage));
}
private void hamburger_btn_Click(object sender, RoutedEventArgs e)
{
shell_splitview.IsPaneOpen = !shell_splitview.IsPaneOpen;
}
}
}
This method of work I found when searching on google to make the NavigationPane work in all the pages and it does work in all the pages just without the Back Navigation.
MainPage.xaml.cs
namespace Testing
{
/// <summary>
/// An empty page that can be used on its own or navigated to within a Frame.
/// </summary>
public sealed partial class MainPage : Page
{
public MainPage()
{
this.InitializeComponent();
NavigationCacheMode = NavigationCacheMode.Enabled;
}
private void Settings_Flyout_Click(object sender, RoutedEventArgs e)
{
this.Frame.Navigate(typeof(SettingsPage));
}
}
}
I have done some searches on google but nothing makes sense because they use some other methods and things get more complicated.
Please let me know what I am doing wrong here and how to make it right. Thanks.
P.S. Let me know if I need to also share the XAML files.
If I use Window.Current.Content = new SplitShellPage(rootFrame); as in place of Window.Current.Content = rootFrame; the SplitView works but the back button does not work
In this situation, the frame currently you are using is shell_splitview.Content.
Because you are using this code for navigating (shell_splitview.Content as Frame).Navigate(typeof(MainPage));. So in App.xaml.cs the method App_BackRequested method try to get the Window.Current.Content as Frame for navigating, the back button will not work.
The solution is provided by the demo in the thread you reference, to add the BackRequested event handle in the page which defined the SplitView. Update your code in SplitShellPage.xaml.cs as follows the back button will work.
public SplitShellPage(Frame frame)
{
this.InitializeComponent();
NavigationCacheMode = NavigationCacheMode.Enabled;
shell_splitview.Content = frame;
(shell_splitview.Content as Frame).Navigate(typeof(MainPage));
SystemNavigationManager.GetForCurrentView().BackRequested += SplitShellPage_BackRequested;
}
private void SplitShellPage_BackRequested(object sender, BackRequestedEventArgs e)
{
Frame myFrame = shell_splitview.Content as Frame;
if (myFrame.CanGoBack)
{
e.Handled = true;
myFrame.GoBack();
}
}
If I use the second line then SplitView doesn't work but back navigation works.
In this situation, we even did not access the SplitShellPage, and didn't access the SplitView. It is just a implemention of back button between two simple page. It works and has noting relationship with the content of SplitView.
The key point for this issue is to clear which frame you are using for navigating now , rootFrame(Window.Current.Content) or the SplitViewContent frame. And navigating back with back button need the same frame.
You can download the demo from the thread you referenced for further testing. And more details please reference Back button navigation.
I recently have released a small application with a trial to the Windows Phone Marketplace, but my application is not working as expected. I have followed http://code.msdn.microsoft.com/Trial-Experience-Sample-c58f21af when making my trial, so that I can call the current 'LicenseInformation' state and block a feature or not depending on the current application's license state. According to the sample application, The LicenseMode property returns a value from the LicenseModes enum (Full, MissingOrRevoked, or Trial) so that your app code needs to check only a single value. There’s also a convenient Boolean IsFull property. Whenever the license mode has changed, or it is likely to have changed, TrialExperienceHelper raises its LicenseChanged event and your app code can handle that event to query LicenseMode or IsFull again. Then, your app can control the availability of features, ads, and your Buy UI as needed.
In my application I have a click event in which I would like to perform an action based on the current LicenseInformation state and upon a count (the count being the number of times an image is saved with particular aspects applied).
Settings.SavedCount.Value records the number of times the save button is clicked, and if the count is above 100 and the application is in trial mode I would like to ask the user if they would like to upgrade, otherwise if the count is less than 100 while the application is in trial mode or if the license is in full mode then the user is allowed to continue with the save process (hopefully that makes logical sense).
void saveButton_Click(object sender, EventArgs e)
{
Settings.SavedCount.Value += 1;
if (TrialViewModel.LicenseModeString == "Trial" && Settings.SavedCount.Value > 100)
{
MessageBoxResult result = MessageBox.Show("You have saved over 100 items! Would you like to continue?", "Congratulations!", MeesageBoxButton.OKCancel);
switch (result)
{
case MessageBoxResult.OK:
//A command takes a parameter so pass null
TrialViewModel.BuyCommand.Execute(null);
break;
case MessageBoxResult.Cancel:
editPagePivotControl.SelectedIndex = 0;
break;
}
}
else if ((TrialViewModel.LicenseModeString == "Trial" && Settings.SavedCount.Value <= 100) || (TrialViewModel.LicenseModeString == "Full")
{
PerformSaveAsync();
}
}
}
When testing in Debug mode and with the sample implementation from the msdn website, the Trial and Full implementations worked properly, and then when in Release mode the license was listed as MissingOrRevoked which I assumed would be called correctly in the marketplace. What is ACTUALLY occuring when i have downloaded the app in the marketplace under both trial and full modes is that the PerformSaveAsync() method is never being called (which ultimately saves the new image and disables the button) and I can use the new image elsewhere. I am having trouble figuring out what the issue may be?
EDIT** In researching I came across http://msdn.microsoft.com/en-us/library/aa691310(v=vs.71).aspx which states that The operation x && y corresponds to the operation x & y, except that y is evaluated only if x is true. and `•The operation x || y corresponds to the operation x | y, except that y is evaluated only if x is false/' . Would this be the cause of the issues? If so, how should they be fixed?
Edit 2** Addtion of TrialViewModel and TrialExperienceHelper.cs for additional info
TrialViewModel
TrialViewModel
#region fields
private RelayCommand buyCommand;
#endregion fields
#region constructors
public TrialViewModel()
{
// Subscribe to the helper class's static LicenseChanged event so that we can re-query its LicenseMode property when it changes.
TrialExperienceHelper.LicenseChanged += TrialExperienceHelper_LicenseChanged;
}
#endregion constructors
#region properties
/// <summary>
/// You can bind the Command property of a Button to BuyCommand. When the Button is clicked, BuyCommand will be
/// invoked. The Button will be enabled as long as BuyCommand can execute.
/// </summary>
public RelayCommand BuyCommand
{
get
{
if (this.buyCommand == null)
{
// The RelayCommand is constructed with two parameters - the action to perform on invocation,
// and the condition under which the command can execute. It's important to call RaiseCanExecuteChanged
// on a command whenever its can-execute condition might have changed. Here, we do that in the TrialExperienceHelper_LicenseChanged
// event handler.
this.buyCommand = new RelayCommand(
param => TrialExperienceHelper.Buy(),
param => TrialExperienceHelper.LicenseMode == TrialExperienceHelper.LicenseModes.Trial);
}
return this.buyCommand;
}
}
public string LicenseModeString
{
get
{
return TrialExperienceHelper.LicenseMode.ToString()/* + ' ' + AppResources.ModeString*/;
}
}
#endregion properties
#region event handlers
// Handle TrialExperienceHelper's LicenseChanged event by raising property changed notifications on the
// properties and commands that
internal void TrialExperienceHelper_LicenseChanged()
{
this.RaisePropertyChanged("LicenseModeString");
this.BuyCommand.RaiseCanExecuteChanged();
}
#endregion event handlers
TrialExperienceHelper.cs
#region enums
/// <summary>
/// The LicenseModes enumeration describes the mode of a license.
/// </summary>
public enum LicenseModes
{
Full,
MissingOrRevoked,
Trial
}
#endregion enums
#region fields
#if DEBUG
// Determines how a debug build behaves on launch. This field is set to LicenseModes.Full after simulating a purchase.
// Calling the Buy method (or navigating away from the app and back) will simulate a purchase.
internal static LicenseModes simulatedLicMode = LicenseModes.Trial;
#endif // DEBUG
private static bool isActiveCache;
private static bool isTrialCache;
#endregion fields
#region constructors
// The static constructor effectively initializes the cache of the state of the license when the app is launched. It also attaches
// a handler so that we can refresh the cache whenever the license has (potentially) changed.
static TrialExperienceHelper()
{
TrialExperienceHelper.RefreshCache();
PhoneApplicationService.Current.Activated += (object sender, ActivatedEventArgs e) => TrialExperienceHelper.
#if DEBUG
// In debug configuration, when the user returns to the application we will simulate a purchase.
OnSimulatedPurchase();
#else // DEBUG
// In release configuration, when the user returns to the application we will refresh the cache.
RefreshCache();
#endif // DEBUG
}
#endregion constructors
#region properties
/// <summary>
/// The LicenseMode property combines the active and trial states of the license into a single
/// enumerated value. In debug configuration, the simulated value is returned. In release configuration,
/// if the license is active then it is either trial or full. If the license is not active then
/// it is either missing or revoked.
/// </summary>
public static LicenseModes LicenseMode
{
get
{
#if DEBUG
return simulatedLicMode;
#else // DEBUG
if (TrialExperienceHelper.isActiveCache)
{
return TrialExperienceHelper.isTrialCache ? LicenseModes.Trial : LicenseModes.Full;
}
else // License is inactive.
{
return LicenseModes.MissingOrRevoked;
}
#endif // DEBUG
}
}
/// <summary>
/// The IsFull property provides a convenient way of checking whether the license is full or not.
/// </summary>
public static bool IsFull
{
get
{
return (TrialExperienceHelper.LicenseMode == LicenseModes.Full);
}
}
#endregion properties
#region methods
/// <summary>
/// The Buy method can be called when the license state is trial. the user is given the opportunity
/// to buy the app after which, in all configurations, the Activated event is raised, which we handle.
/// </summary>
public static void Buy()
{
MarketplaceDetailTask marketplaceDetailTask = new MarketplaceDetailTask();
marketplaceDetailTask.ContentType = MarketplaceContentType.Applications;
marketplaceDetailTask.Show();
}
/// <summary>
/// This method can be called at any time to refresh the values stored in the cache. We re-query the application object
/// for the current state of the license and cache the fresh values. We also raise the LicenseChanged event.
/// </summary>
public static void RefreshCache()
{
TrialExperienceHelper.isActiveCache = CurrentApp.LicenseInformation.IsActive;
TrialExperienceHelper.isTrialCache = CurrentApp.LicenseInformation.IsTrial;
TrialExperienceHelper.RaiseLicenseChanged();
}
private static void RaiseLicenseChanged()
{
if (TrialExperienceHelper.LicenseChanged != null)
{
TrialExperienceHelper.LicenseChanged();
}
}
#if DEBUG
private static void OnSimulatedPurchase()
{
TrialExperienceHelper.simulatedLicMode = LicenseModes.Full;
TrialExperienceHelper.RaiseLicenseChanged();
}
#endif // DEBUG
#endregion methods
#region events
/// <summary>
/// The static LicenseChanged event is raised whenever the value of the LicenseMode property has (potentially) changed.
/// </summary>
public static event LicenseChangedEventHandler LicenseChanged;
#endregion events
If your dev builds work and the only difference is with the app being published via the store then I think it's very unlikely to be your logic.
When you submitted the app, are you sure you checked the option to be able to use the trial functionality in the app?
If you didn't check this then it won't work in a released app.
Regarding your edit, I don't see any problem with your condition, your quote is just that the operator is lazy, evaluating only what is needed to determine the result (for example when you do x&& y if x is false, x&& false=> false and x&& true==false which is the same result so it don't evaluate y).
Also like I said in your previous question even the windows phone 7 api still work on windows phone 8 so if you are creating code for both platform there is probably no need to use the new api specifically for wp8.
In this code I don't see any problem but why do you convert the LicenseModes enum to string, using the enum will add some type safety and prevent you to do some invalid comparison.
The only problem is where you set LicenseModeString or a problem inside PerformSaveAsync?
I'm trying to make a Setting flyout easily accessible in all pages. I looked at the Settings example at http://code.msdn.microsoft.com/windowsapps/App-settings-sample-1f762f49/sourcecode?fileId=50851&pathId=2033699455.
However there are about a dozen functions and it's just dumb to have to copy/paste/maintain an undetermined number of copies of the same code in each page. So I took the code for the popup and put it in a base class that inherits from LayoutAwarePage base class. My pages then inherit from this new class. Ex:
// Base class declaration that includes settings flyout code
public class SettingsFlyoutAwarePage : myApp.Common.LayoutAwarePage
{
// Settings flyout code here
}
// Page declaration
public sealed partial class GroupedItemsPage : myApp.Common.SettingsFlyoutAwarePage
{
// Standard working page stuff here
}
Here is the actual code to create popup that IS being called and executed in the SettingsFlyoutAwarePage base class, which is identical to the sample code, but nothing actually appears on screen:
void onSettingsCommand(IUICommand command)
{
// Create a Popup window which will contain our flyout.
settingsPopup = new Popup();
settingsPopup.Closed += OnPopupClosed;
Window.Current.Activated += OnWindowActivated;
settingsPopup.IsLightDismissEnabled = true;
settingsPopup.Width = settingsWidth;
settingsPopup.Height = windowBounds.Height;
// Add the proper animation for the panel.
settingsPopup.ChildTransitions = new TransitionCollection();
settingsPopup.ChildTransitions.Add(new PaneThemeTransition()
{
Edge = (SettingsPane.Edge == SettingsEdgeLocation.Right) ?
EdgeTransitionLocation.Right :
EdgeTransitionLocation.Left
});
// Create a SettingsFlyout the same dimenssions as the Popup.
SettingsFlyout mypane = new SettingsFlyout();
mypane.Width = settingsWidth;
mypane.Height = windowBounds.Height;
// Place the SettingsFlyout inside our Popup window.
settingsPopup.Child = mypane;
// Let's define the location of our Popup.
settingsPopup.SetValue(Canvas.LeftProperty, SettingsPane.Edge == SettingsEdgeLocation.Right ? (windowBounds.Width - settingsWidth) : 0);
settingsPopup.SetValue(Canvas.TopProperty, 0);
settingsPopup.IsOpen = true;
}
While I can step through all the code and it all appears to execute just fine, I never actually see the flyout appear. Is it at least theoretically possible to do this from an inherited base class?
Did you implement the onCommandsRequested function as described in demo?
void onCommandsRequested(SettingsPane settingsPane, SettingsPaneCommandsRequestedEventArgs eventArgs)
{
UICommandInvokedHandler handler = new UICommandInvokedHandler(onSettingsCommand);
SettingsCommand generalCommand = new SettingsCommand("DefaultsId", "Defaults", handler);
eventArgs.Request.ApplicationCommands.Add(generalCommand);
}
If this helps anyone, here is a Settings flyout-aware class that you can inherit your XAML pages from. Of course you still have to implement the popup itself (demo code link)
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Windows.Foundation;
using Windows.UI.ApplicationSettings;
using Windows.UI.Popups;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Media.Animation;
using Windows.UI.Xaml.Navigation;
namespace MyApp.Common
{
[Windows.Foundation.Metadata.WebHostHidden]
public class MyAppBasePage : MyApp.Common.LayoutAwarePage
{
public MyAppBasePage()
{
}
private bool isSettingCharmEventRegistered;
// Used to determine the correct height to ensure our custom UI fills the screen.
private Rect windowBounds;
// Desired width for the settings UI. UI guidelines specify this should be 346 or 646 depending on your needs.
private double settingsWidth = 646;
// This is the container that will hold our custom content.
private Popup settingsPopup;
protected override void OnNavigatedFrom(NavigationEventArgs e)
{
base.OnNavigatedFrom(e);
// Added to make sure the event handler for CommandsRequested is cleaned up before other scenarios.
if (this.isSettingCharmEventRegistered)
{
SettingsPane.GetForCurrentView().CommandsRequested -= onCommandsRequested;
this.isSettingCharmEventRegistered = false;
}
// Unregister the event that listens for events when the window size is updated.
Window.Current.SizeChanged -= OnWindowSizeChanged;
}
protected override void OnNavigatedTo(NavigationEventArgs e)
{
base.OnNavigatedTo(e);
windowBounds = Window.Current.Bounds;
// Added to listen for events when the window size is updated.
Window.Current.SizeChanged += OnWindowSizeChanged;
// Added to make sure the event handler for CommandsRequested is cleaned up before other scenarios.
if (!this.isSettingCharmEventRegistered)
{
SettingsPane.GetForCurrentView().CommandsRequested += onCommandsRequested;
this.isSettingCharmEventRegistered = true;
}
}
/// <summary>
/// Invoked when the window size is updated.
/// </summary>
/// <param name="sender">Instance that triggered the event.</param>
/// <param name="e">Event data describing the conditions that led to the event.</param>
void OnWindowSizeChanged(object sender, Windows.UI.Core.WindowSizeChangedEventArgs e)
{
windowBounds = Window.Current.Bounds;
}
/// <summary>
/// We use the window's activated event to force closing the Popup since a user maybe interacted with
/// something that didn't normally trigger an obvious dismiss.
/// </summary>
/// <param name="sender">Instance that triggered the event.</param>
/// <param name="e">Event data describing the conditions that led to the event.</param>
private void OnWindowActivated(object sender, Windows.UI.Core.WindowActivatedEventArgs e)
{
if (e.WindowActivationState == Windows.UI.Core.CoreWindowActivationState.Deactivated)
{
settingsPopup.IsOpen = false;
}
}
/// <summary>
/// When the Popup closes we no longer need to monitor activation changes.
/// </summary>
/// <param name="sender">Instance that triggered the event.</param>
/// <param name="e">Event data describing the conditions that led to the event.</param>
void OnPopupClosed(object sender, object e)
{
Window.Current.Activated -= OnWindowActivated;
}
/// <summary>
/// This event is generated when the user opens the settings pane. During this event, append your
/// SettingsCommand objects to the available ApplicationCommands vector to make them available to the
/// SettingsPange UI.
/// </summary>
/// <param name="settingsPane">Instance that triggered the event.</param>
/// <param name="eventArgs">Event data describing the conditions that led to the event.</param>
void onCommandsRequested(SettingsPane settingsPane, SettingsPaneCommandsRequestedEventArgs eventArgs)
{
UICommandInvokedHandler handler = new UICommandInvokedHandler(onSettingsCommand);
SettingsCommand generalCommand = new SettingsCommand("DefaultsId", "Defaults", handler);
eventArgs.Request.ApplicationCommands.Add(generalCommand);
}
/// <summary>
/// This the event handler for the "Defaults" button added to the settings charm. This method
/// is responsible for creating the Popup window will use as the container for our settings Flyout.
/// The reason we use a Popup is that it gives us the "light dismiss" behavior that when a user clicks away
/// from our custom UI it just dismisses. This is a principle in the Settings experience and you see the
/// same behavior in other experiences like AppBar.
/// </summary>
/// <param name="command"></param>
void onSettingsCommand(IUICommand command)
{
// Create a Popup window which will contain our flyout.
settingsPopup = new Popup();
settingsPopup.Closed += OnPopupClosed;
Window.Current.Activated += OnWindowActivated;
settingsPopup.IsLightDismissEnabled = true;
settingsPopup.Width = settingsWidth;
settingsPopup.Height = windowBounds.Height;
// Add the proper animation for the panel.
settingsPopup.ChildTransitions = new TransitionCollection();
settingsPopup.ChildTransitions.Add(new PaneThemeTransition()
{
Edge = (SettingsPane.Edge == SettingsEdgeLocation.Right) ?
EdgeTransitionLocation.Right :
EdgeTransitionLocation.Left
});
// Create a SettingsFlyout the same dimenssions as the Popup.
SettingsFlyout mypane = new SettingsFlyout();
mypane.Width = settingsWidth;
mypane.Height = windowBounds.Height;
// Place the SettingsFlyout inside our Popup window.
settingsPopup.Child = mypane;
// Let's define the location of our Popup.
settingsPopup.SetValue(Canvas.LeftProperty, SettingsPane.Edge == SettingsEdgeLocation.Right ? (windowBounds.Width - settingsWidth) : 0);
settingsPopup.SetValue(Canvas.TopProperty, 0);
settingsPopup.IsOpen = true;
}
}
}
I'm a newbie to WMI and I need to implement RegistryValueChangeEvent in a C# service.
I need an event handler that gets triggered each time any one of a set of registry values is changed. I want behavior similar to the FileSystemWatcher class's Changed event, but for registry values.
If there's some other technique I could use to accomplish the same task, I'd appreciate that as well. My minimum requirement is that it be a better solution than what I have now: polling every 20 seconds and comparing the registry value with the last result.
Please provide example code in your answer. If I can get an example for watching just one registry value, that would be fine.
I need a solution in .Net 2.0
Thanks.
WMI can sometimes be interesting to work with...I think I understand your question, so take a look at the code snippet below and let me know if it's what you're looking for.
// ---------------------------------------------------------------------------------------------------------------------
// <copyright file="Program.cs" company="">
//
// </copyright>
// <summary>
// Defines the WmiChangeEventTester type.
// </summary>
// ---------------------------------------------------------------------------------------------------------------------
namespace WmiExample
{
using System;
using System.Management;
/// <summary>
/// </summary>
public class WmiChangeEventTester
{
/// <summary>
/// Initializes a new instance of the <see cref="WmiChangeEventTester"/> class.
/// </summary>
public WmiChangeEventTester()
{
try
{
// Your query goes below; "KeyPath" is the key in the registry that you
// want to monitor for changes. Make sure you escape the \ character.
WqlEventQuery query = new WqlEventQuery(
"SELECT * FROM RegistryValueChangeEvent WHERE " +
"Hive = 'HKEY_LOCAL_MACHINE'" +
#"AND KeyPath = 'SOFTWARE\\Microsoft\\.NETFramework' AND ValueName='InstallRoot'");
ManagementEventWatcher watcher = new ManagementEventWatcher(query);
Console.WriteLine("Waiting for an event...");
// Set up the delegate that will handle the change event.
watcher.EventArrived += new EventArrivedEventHandler(HandleEvent);
// Start listening for events.
watcher.Start();
// Do something while waiting for events. In your application,
// this would just be continuing business as usual.
System.Threading.Thread.Sleep(100000000);
// Stop listening for events.
watcher.Stop();
}
catch (ManagementException managementException)
{
Console.WriteLine("An error occurred: " + managementException.Message);
}
}
/// <summary>
/// </summary>
/// <param name="sender">
/// The sender.
/// </param>
/// <param name="e">
/// The e.
/// </param>
private void HandleEvent(object sender, EventArrivedEventArgs e)
{
Console.WriteLine("Received an event.");
// RegistryKeyChangeEvent occurs here; do something.
}
/// <summary>
/// </summary>
public static void Main()
{
// Just calls the class above to check for events...
WmiChangeEventTester receiveEvent = new WmiChangeEventTester();
}
}
}
You really don't need WMI, as others have pointed out. I too have used RegistryMonitor with no problems.
If you need an example, there's already example code for the RegistryMonitor on the page itself. Did you scroll down to this bit on the code project:
public class MonitorSample
{
static void Main()
{
RegistryMonitor monitor = new
RegistryMonitor(RegistryHive.CurrentUser, "Environment");
monitor.RegChanged += new EventHandler(OnRegChanged);
monitor.Start();
while(true);
monitor.Stop();
}
private void OnRegChanged(object sender, EventArgs e)
{
Console.WriteLine("registry key has changed");
}
}
Are you limited to WMI?
If not you can use RegNotifyChangeKeyValue wrappers like RegistryMonitor
You'll need to utilize WMI for it. See http://msdn.microsoft.com/en-us/library/aa393035.aspx