要在UWP应用中获取屏幕分辨率，您可以尝试使用DisplayInformation.ScreenHeightInRawPixels Property和DisplayInformation.ScreenWidthInRawPixels Property。

类似于以下代码：

  protected override void OnLaunched(LaunchActivatedEventArgs e)
    {
        Frame rootFrame = Window.Current.Content as Frame;
           ........
            Window.Current.Activate();
        }

        //screen resolution
        string heightsize = DisplayInformation.GetForCurrentView().ScreenHeightInRawPixels.ToString();
        string widthsize = DisplayInformation.GetForCurrentView().ScreenWidthInRawPixels.ToString();
        Size mysize = new Size(Convert.ToDouble(widthsize),Convert.ToDouble(heightsize));


        ApplicationView.PreferredLaunchViewSize = mysize;
        ApplicationView.PreferredLaunchWindowingMode = ApplicationViewWindowingMode.PreferredLaunchViewSize;
    }

我的分辨率是1920 * 1080。在我的测试中，它可以将屏幕分辨率正确设置为1920 * 1080。

最终，我选择在我的工作区（Windows任务栏上方的屏幕区域）中最大化我的UWP App（用C＃编写）。我想提供最少的说明来创建您正在运行的最大化应用程序。

我在Visual Studio Community 2019中使用C＃创建了一个新的默认空白应用程序（通用Windows），称为“绘制边界框”。我在此处添加了空格，以便可以从“开始”菜单中访问包含空格的“绘图边界框”。

我用以下代码块替换了“ App.xaml.cs”的内容。

namespace Draw_Bounding_Boxes
{
    /// <summary>
    /// Provides application-specific behavior to supplement the default Application class.
    /// </summary>
    sealed partial class App : Windows.UI.Xaml.Application
    {
        /// <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(Windows.ApplicationModel.Activation.LaunchActivatedEventArgs e)
        {
            // Resize app.
            uint screenWidthInRawPixels = Windows.Graphics.Display.DisplayInformation.GetForCurrentView().ScreenWidthInRawPixels;
            uint screenHeightInRawPixels = Windows.Graphics.Display.DisplayInformation.GetForCurrentView().ScreenHeightInRawPixels;
            double rawPixelsPerViewPixel = Windows.Graphics.Display.DisplayInformation.GetForCurrentView().RawPixelsPerViewPixel;
            double screenWidthInViewPixels = System.Convert.ToDouble(screenWidthInRawPixels) / rawPixelsPerViewPixel;
            double screenHeightInViewPixels = System.Convert.ToDouble(screenHeightInRawPixels) / rawPixelsPerViewPixel;

            // If offsetToScreenWidthInViewPixels is less than 15,// on first load app will be of default size,and on second load app will be full screen.
            // A loaded image will have height equal to full screen height minus app title bar height minus app toolbar height minus 5 view pixels of padding.
            // Part of a loaded image with aspect ratio less than one will be behind Windows taskbar.
            // This is all very complicated and undesirable.
            // If offsetToScreenHeightInViewPixels is less than 40,and on second load app will be full screen.
            // A loaded image will have height equal to full screen height minus app title bar height minus app toolbar height minus 5 view pixels of padding.
            // Part of a loaded image with aspect ratio less than one will be behind Windows taskbar.
            // This is all very complicated and undesirable.
            // If offsetToScreenWidthInViewPixels is greater than or equal to 15 and offsetToScreenHeightInViewPixels is greater than or equal to 40,// on first load app will be of PreferredLaunchViewSize,and a loaded image with aspect ratio less than one will have height exactly equal to height of app minus app title bar height minus app toolbar height.
            // If PreferredLaunchViewSize.Height is only screenHeightInViewPixels - offsetToScreenHeightInViewPixels,// part of app and a loaded image with aspect ratio less than one will be behind taskbar.
            // If taskbarHeight is taken off of screenHeightInViewPixels - offsetToScreenHeightInViewPixels,// bottom of app and coincident bottom of loaded image will be slightly above taskbar.
            // I consider this ideal.
            double offsetToScreenWidthInViewPixels = 15;
            double offsetToScreenHeightInViewPixels = 40;
            double taskbarHeight = 40;
            Windows.UI.ViewManagement.ApplicationView.PreferredLaunchViewSize = new Windows.Foundation.Size(screenWidthInViewPixels - offsetToScreenWidthInViewPixels,screenHeightInViewPixels - offsetToScreenHeightInViewPixels - taskbarHeight);
            Windows.UI.ViewManagement.ApplicationView.PreferredLaunchWindowingMode = Windows.UI.ViewManagement.ApplicationViewWindowingMode.PreferredLaunchViewSize;

            // Set the app window to a new Frame.
            Windows.UI.Xaml.Controls.Frame rootFrame = new Windows.UI.Xaml.Controls.Frame();
            Windows.UI.Xaml.Window.Current.Content = rootFrame;

            // Navigate the frame to the initial default page.
            rootFrame.Navigate(typeof(MainPage),e.Arguments);

            // Attempts to activate the application window by bringing it to the foreground and setting the input focus to it.
            Windows.UI.Xaml.Window.Current.Activate();

        } // protected override void OnLaunched
    } // sealed partial class App
} // namespace Draw_Bounding_Boxes

我在{MainPage.xaml“的x:Name="page"标签中添加了属性<Page>。

我从MainPage.xaml中删除了<Grid> </Grid>环境。

我用以下代码块替换了“ MainPage.xaml.cs”的内容。

// Create namespace Draw_Bounding_Boxes to contain all classes associated with our app.
namespace Draw_Bounding_Boxes
{
    // Create class MainPage that inherits fields and methods from Windows.UI.Xaml.Controls.Page and
    // is used to declare and define user-interface elements and functionality.
    public sealed partial class MainPage : Windows.UI.Xaml.Controls.Page
    {
        // Create constructor public MainPage.
        public MainPage()
        {
            // Necessary to instantiate this Page,add a stackPanel to this Page,et cetera.
            this.InitializeComponent();

            // Find width of app in view pixels and height between bottom of app and bottom of title bar in view pixels.
            double widthOfAppInViewPixels = Windows.UI.ViewManagement.ApplicationView.PreferredLaunchViewSize.Width;
            double heightBetweenBottomOfAppAndBottomOfTitleBarInViewPixels = Windows.UI.ViewManagement.ApplicationView.PreferredLaunchViewSize.Height;

            // Create a stackPanel.
            Windows.UI.Xaml.Controls.StackPanel stackPanel = new Windows.UI.Xaml.Controls.StackPanel();

            // Create a toolbar with width equal to the width of the app,height equal to 50 view pixels,and background color of light blue that has one row and four columns.
            Windows.UI.Xaml.Controls.Grid toolbar = new Windows.UI.Xaml.Controls.Grid();
            toolbar.Width = widthOfAppInViewPixels;
            toolbar.Height = 50;
            toolbar.Background = new Windows.UI.Xaml.Media.SolidColorBrush(Windows.UI.Colors.AliceBlue);
            Windows.UI.Xaml.Controls.RowDefinition row = new Windows.UI.Xaml.Controls.RowDefinition();
            toolbar.RowDefinitions.Add(row);
            Windows.UI.Xaml.Controls.ColumnDefinition column = new Windows.UI.Xaml.Controls.ColumnDefinition();
            column.Width = new Windows.UI.Xaml.GridLength(widthOfAppInViewPixels);
            toolbar.ColumnDefinitions.Add(column);

            stackPanel.Children.Add(toolbar);

            page.Content = stackPanel;
        }
    }
}