uwp

问题 I am learning Entity Framework with UWP. I tried dropping a table by deleting it from DbContext. When running the code after migration I received an error that dropping primary key is not supported with UWP. This article, https://docs.efproject.net/en/latest/providers/sqlite/limitations.html, recommends using sql(string) method. This article, https://msdn.microsoft.com/en-us/data/jj592907.aspx, has an example I am trying to follow. using (var context = new BloggingContext()) { var blogs =

问题 I´ve an UWP application with a ListBox. When I click on a related listboxitem I change a frame content. ( I am using the SelectionChanged event for this. ) Inside this Frame I can go and do multiple operations such as move into another Page Frame. (And keep the sme listboxItem selected. ) So I have -> MainPage -> ContactsPage -> ContactsDetailPage. (On the listBox I have the "Contacts" item selected). But, if on "ContactsDetailsPage" I click on "Contacts" ListBoxItem the SelectionChanged

问题 I'm trying to show a "back" button on my (Xamarin.Forms) UWP app when running on a desktop PC. I'm running the following code in the App 's OnLaunched method: SystemNavigationManager.GetForCurrentView().AppViewBackButtonVisibility = AppViewBackButtonVisibility.Visible; But the back button is not shown. The line does work on a pure UWP app. But not in Xamarin.Forms. Is there any additional step needed to get this working? EDIT It seems now that when navigating to a new NavigationPage(page)

问题 I encountered a really strange problem when trying to connect my raspberry pi to my Arduino Uno through serial (usb). serialPort = await SerialDevice.FromIdAsync(myDevices[0].Id); Always returns null. I tried many things and it won't until I put it in a loop and then it works the second time. So I removed the loop and made it run 2 times. This is my output begintest testrange \\?\USB#VID_2341&PID_0001#55639313633351210252#{86e0d1e0-8089-11d0-9ce4-08003e301f73} test1 null begintest ok ok2

问题 I want to use a background task for my UWP app. The below code, is my back button click event in windows mobile: private async void MainPage_BackRequested(object sender, BackRequestedEventArgs e) { var access= await BackgroundExecutionManager.RequestAccessAsync(); var task = new BackgroundTaskBuilder { Name="My task",TaskEntryPoint=typeof(backGroundTask.Class1).ToString() }; trigger = new ApplicationTrigger(); task.SetTrigger(trigger); task.Register(); //var result = await trigger

问题 I cloned the official github repo of OpenCV and used CMake to generate the VS Solution. cmake -G "Visual Studio 14 2015" -DCMAKE_SYSTEM_NAME=WindowsStore -DCMAKE_SYSTEM_VERSION="10.0" . As you can see, I want to build OpenCV for UWP 32-Bit. When building in VS 2015 the opencv_core module fails with: Error C2664 'BOOL CreateDirectoryA(LPCSTR,LPSECURITY_ATTRIBUTES)': cannot convert argument 1 from 'wchar_t [260]' to 'LPCSTR' Error C2039 'CreateFileA': is not a member of '`global namespace''

问题 Installing custom fonts (.ttf) to windows 10 ioT device(Raspberry pi 3) . Im working on UWP app that renders the font from weathericons-regular-webfont.ttf . Initially I had to install the .ttf file in my computer in order to render these specific fonts. I had tried adding the .ttf file to my project but when deploying the app im not able to see the app's folder on the IOT device. Even if the .ttf was placed on the app folder i believe it needs to be installed separately. 回答1: the way to use

问题 I am working on a windows 10 app, and I have to store data locally, but I am new to Entity Framework, So kindly suggest me which database technique should i use for storing data locally? Also please someone let me know if Relam supports windows 10 apps for UWP? Thanks in advance. 回答1: Update: Realm released UWP support. Check the announcement here: https://news.realm.io/news/realm-mobile-database-for-universal-windows-platform/ Old answer: There an Issue, realm/realm-core#2059, discussing

问题 When the AreStickyGroupHeadersEnabled property value is True on the ListView's ItemsStackPanel, the group header ( ListViewHeaderItem ) at the top is always covering the first visible ListViewItem. And in the situations when the group header's height is greater than the item's height, the item is being completely hidden from view beneath the group header. For some reason ItemsStackPanel.FirstVisibleIndex reports the hidden item as visible. Is it possible to make the sticky group header

问题 tl;dr I have 3 Pages MainPage.xaml , BlankPage1.xaml , BlankPage2.xaml with Button on MainPage and BlankPage1 that navigates to BlankPage1 and BlankPage2 Respectively. I enabled System Back Button so that i can go back to previous page. Button Tap on MainPage navigates to BlankPage1 and Button Tap on BlankPage1 navigates to BlankPage2 . This works fine. Problem: When I tap Back Button on BlankPage2 it goes back to BlankPage . Now when I tap the Button on BlankPage1 it goes to BlankPage2 but