C# Xaml.UIElement类代码示例

 private void LostFocusHandler(object sender, RoutedEventArgs e)
 {
     if (lastFocusedElement == (UIElement)sender)
     {
         lastFocusedElement = null;
     }
 }

        /// <summary>
        /// Invoked whenever application code or internal processes (such as a rebuilding layout pass) call ApplyTemplate.
        /// In simplest terms, this means the method is called just before a UI element displays in your app.
        /// Override this method to influence the default post-template logic of a class.
        /// </summary>
        protected override void OnApplyTemplate()
        {
            // Border
            this.border = this.GetTemplateChild(BorderPartName) as Border;
            if (this.border != null)
            {
                this.border.ManipulationStarted += Border_ManipulationStarted;
                this.border.ManipulationDelta += Border_ManipulationDelta;
                this.border.ManipulationCompleted += Border_ManipulationCompleted;
                this.border.Tapped += Border_Tapped;
                this.border.PointerEntered += Border_PointerEntered;

                // Move Canvas properties from control to border.
                Canvas.SetLeft(this.border, Canvas.GetLeft(this));
                Canvas.SetLeft(this, 0);
                Canvas.SetTop(this.border, Canvas.GetTop(this));
                Canvas.SetTop(this, 0);

                // Move Margin to border.
                this.border.Padding = this.Margin;
                this.Margin = new Thickness(0);
            }
            else
            {
                // Exception
                throw new Exception("Floating Control Style has no Border.");
            }

            // Overlay
            this.overlay = GetTemplateChild(OverlayPartName) as UIElement;

            this.Loaded += Floating_Loaded;
        }

        /// <summary>
        /// Shows a popup dialog for the specified model relative to the <paramref name="placementTarget"/>.
        /// </summary>
        /// <param name="rootModel">The root model.</param>
        /// <param name="placementTarget">The placement target.</param>
        /// <param name="viewSettings">The optional dialog settings.</param> 
        public void ShowFlyout(object rootModel, UIElement placementTarget, IDictionary<string, object> viewSettings = null) {
            var view = ViewLocator.LocateForModel(rootModel, null, null);
            ViewModelBinder.Bind(rootModel, view, null);

            var flyout = new Flyout
                {
                    Content = view,
                    PlacementTarget = placementTarget,
                };

            ApplySettings(flyout, viewSettings);
            flyout.IsOpen = true;

            var deactivator = rootModel as IDeactivate;
            if (deactivator != null) {
                EventHandler<object> closed = null;
                closed = (s, e) => {
                    deactivator.Deactivate(true);
                    flyout.Closed -= closed;
                };

                flyout.Closed += closed;
            }

            var activator = rootModel as IActivate;
            if (activator != null) {
                activator.Activate();
            }
        }

        public ManipulationInputProcessor(Windows.UI.Input.GestureRecognizer gr, Windows.UI.Xaml.UIElement target, Windows.UI.Xaml.UIElement referenceframe)
        {
            this.gestureRecognizer = gr;
            this.element = target;
            this.reference = referenceframe;

            this.gestureRecognizer.GestureSettings =
                Windows.UI.Input.GestureSettings.Tap |
                Windows.UI.Input.GestureSettings.Hold | //hold must be set in order to recognize the press & hold gesture
                Windows.UI.Input.GestureSettings.RightTap |
                Windows.UI.Input.GestureSettings.ManipulationTranslateX |
                Windows.UI.Input.GestureSettings.ManipulationTranslateY |
                Windows.UI.Input.GestureSettings.ManipulationRotate |
                Windows.UI.Input.GestureSettings.ManipulationScale |
                Windows.UI.Input.GestureSettings.ManipulationTranslateInertia |
                Windows.UI.Input.GestureSettings.ManipulationRotateInertia |
                Windows.UI.Input.GestureSettings.ManipulationMultipleFingerPanning | //reduces zoom jitter when panning with multiple fingers
                Windows.UI.Input.GestureSettings.ManipulationScaleInertia;

            // Set up pointer event handlers. These receive input events that are used by the gesture recognizer.
            this.element.PointerCanceled += OnPointerCanceled;
            this.element.PointerPressed += OnPointerPressed;
            this.element.PointerReleased += OnPointerReleased;
            this.element.PointerMoved += OnPointerMoved;

            // Set up event handlers to respond to gesture recognizer output
            this.gestureRecognizer.Tapped += OnTapped;
            this.gestureRecognizer.RightTapped += OnRightTapped;
            this.gestureRecognizer.ManipulationStarted += OnManipulationStarted;
            this.gestureRecognizer.ManipulationUpdated += OnManipulationUpdated;
            this.gestureRecognizer.ManipulationCompleted += OnManipulationCompleted;
            InitializeTransforms();
        }

        async System.Threading.Tasks.Task<Windows.Storage.StorageFile> CaptureAndSave(UIElement element)
        {
            // capture
            var bitmap = new Windows.UI.Xaml.Media.Imaging.RenderTargetBitmap();
            await bitmap.RenderAsync(element);
            var picker = new Windows.Storage.Pickers.FileSavePicker
            {
                SuggestedStartLocation = Windows.Storage.Pickers.PickerLocationId.PicturesLibrary,
                FileTypeChoices = { { "JPEG", new[] { ".jpg" } } },
                SuggestedFileName = "Image",
                DefaultFileExtension = ".jpg",
                CommitButtonText = "Save",
            };

            // save
            var file = await picker.PickSaveFileAsync();
            using (var stream = await file.OpenStreamForWriteAsync())
            {

                var pixel = await bitmap.GetPixelsAsync();
                var dpi = Windows.Graphics.Display.DisplayInformation.GetForCurrentView().LogicalDpi;
                var random = stream.AsRandomAccessStream();
                var jpg = Windows.Graphics.Imaging.BitmapEncoder.JpegEncoderId;
                var encoder = await Windows.Graphics.Imaging.BitmapEncoder.CreateAsync(jpg, random);
                var format = Windows.Graphics.Imaging.BitmapPixelFormat.Bgra8;
                var alpha = Windows.Graphics.Imaging.BitmapAlphaMode.Ignore;
                var width = (uint)bitmap.PixelWidth;
                var height = (uint)bitmap.PixelHeight;
                encoder.SetPixelData(format, alpha, width, height, dpi, dpi, pixel.ToArray());
                await encoder.FlushAsync();
            }
            return file;
        }

        public async Task<string> RenderToBase64(UIElement element)
        {
            RenderTargetBitmap rtb = new RenderTargetBitmap();
            await rtb.RenderAsync(element);

            var pixelBuffer = await rtb.GetPixelsAsync();
            var pixels = pixelBuffer.ToArray();

            // Useful for rendering in the correct DPI
            var displayInformation = DisplayInformation.GetForCurrentView();

            var stream = new InMemoryRandomAccessStream();
            var encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.PngEncoderId, stream);
            encoder.SetPixelData(BitmapPixelFormat.Bgra8,
                                 BitmapAlphaMode.Premultiplied,
                                 (uint)rtb.PixelWidth,
                                 (uint)rtb.PixelHeight,
                                 displayInformation.RawDpiX,
                                 displayInformation.RawDpiY,
                                 pixels);

            await encoder.FlushAsync();
            stream.Seek(0);

            // read bytes
            var bytes = new byte[stream.Size];
            await stream.AsStream().ReadAsync(bytes, 0, bytes.Length);

            // create base64
            return Convert.ToBase64String(bytes);
        }

 private void RunIfSelected(UIElement element, Action action)
 {
     if (ChartsList.SelectedItem == element)
     {
         action.Invoke();
     }
 }

        public AdnGestureManager(
            UIElement window, 
            AdnRenderer renderer)
        {
            _window = window;

            _renderer = renderer;

            _pointerMode = PointerMode.kIdleMode;

            _accumulator = new ValueAccumulator(
                -30.0 * 1000.0 / 5.0,
                -100.0 * 1000.0 / 5.0,
                -5.0 * 1000.0 / 5.0);

            _pointers = new Dictionary<uint, PointerPoint>();

            window.PointerMoved += OnPointerMoved;
            window.PointerPressed += OnPointerPressed;
            window.PointerReleased += OnPointerReleased;
            window.PointerWheelChanged += OnPointerWheelChanged;

            _gr = new GestureRecognizer();

            _gr.GestureSettings =
              GestureSettings.Tap |
              GestureSettings.Drag |
              GestureSettings.DoubleTap |
              GestureSettings.ManipulationScale;

            _gr.Tapped += OnTapped;
            _gr.ManipulationStarted += OnManipulationStarted;
            _gr.ManipulationUpdated += OnManipulationUpdated;
            _gr.ManipulationCompleted += OnManipulationCompleted;
        }

        // Unused and untested 
        public static void ShowMessage(string message, UIElement placementTarget, PlacementMode placementMode=PlacementMode.Top)
        {
            var f = new Callisto.Controls.Flyout();

            var b = new Border()
                           {
                               Width = 300,
                               Height = 125
                           };

            TextBlock tb = new TextBlock();
            tb.HorizontalAlignment = HorizontalAlignment.Center;
            tb.VerticalAlignment = VerticalAlignment.Center;
            tb.TextWrapping = TextWrapping.Wrap;
            tb.FontSize = 12f;
            tb.Text = message;

            b.Child = tb;

            f.Content = b;

            f.Placement = placementMode;
            f.PlacementTarget = placementTarget;

            f.IsOpen = true;
        }

        public void Initialize(UIElement host, CompositionImage sourceElement, object payload)
        {
            _host = host;
            _parent = host;
            _payload = payload;

            // Make a copy of the sourceElement's sprite so we can hand it off to the next page
            SpriteVisual sourceSprite = sourceElement.SpriteVisual;
            Compositor compositor = sourceSprite.Compositor;
            _sprite = compositor.CreateSpriteVisual();
            _sprite.Size = sourceSprite.Size;
            _sprite.Brush = sourceElement.SurfaceBrush;

            // We're going to use the backing surface, make sure it doesn't get released
            sourceElement.SharedSurface = true;

            // Determine the offset from the host to the source element used in the transition
            GeneralTransform coordinate = sourceElement.TransformToVisual(_parent);
            Point position = coordinate.TransformPoint(new Point(0, 0));

            // Set the sprite to that offset relative to the host
            _sprite.Offset = new Vector3((float)position.X, (float)position.Y, 0);

            // Set the sprite as the content under the host
            ElementCompositionPreview.SetElementChildVisual(_parent, _sprite);
        }

        public virtual void SetPrintContent(UIElement content)
        {
            if (content == null)
                return;

            PrintContent = content;
        }

 public static ContainerVisual GetVisual(UIElement element)
 {
     var hostVisual = ElementCompositionPreview.GetElementVisual(element);
     ContainerVisual root = hostVisual.Compositor.CreateContainerVisual();
     ElementCompositionPreview.SetElementChildVisual(element, root);
     return root;
 }

        /// <summary>
        /// Displays the compatible scenarios and hides the non-compatible ones.
        /// If there are no supported devices, the scenarioContainer will be hidden and an error message
        /// will be displayed.
        /// </summary>
        /// <param name="scenarios">The key is the device type that the value, scenario, supports.</param>
        /// <param name="scenarioContainer">The container that encompasses all the scenarios that are specific to devices</param>
        public static void SetUpDeviceScenarios(Dictionary<DeviceType, UIElement> scenarios, UIElement scenarioContainer)
        {
            UIElement supportedScenario = null;

            if (EventHandlerForDevice.Current.IsDeviceConnected)
            {
                foreach (KeyValuePair<DeviceType, UIElement> deviceScenario in scenarios)
                {
                    // Enable the scenario if it's generic or the device type matches
                    if ((deviceScenario.Key == DeviceType.All)
                        || (deviceScenario.Key == Utilities.GetDeviceType(EventHandlerForDevice.Current.Device)))
                    {
                        // Make the scenario visible in case other devices use the same scenario and collapsed it.
                        deviceScenario.Value.Visibility = Visibility.Visible;

                        supportedScenario = deviceScenario.Value;
                    }
                    else if (deviceScenario.Value != supportedScenario)
                    {
                        // Don't hide the scenario if it is supported by the current device and is shared by other devices

                        deviceScenario.Value.Visibility = Visibility.Collapsed;
                    }
                }
            }

            if (supportedScenario == null)
            {
                // Hide the container so that common elements shared across scenarios are also hidden
                scenarioContainer.Visibility = Visibility.Collapsed;

                NotifyDeviceNotConnected();
            }
        }

        public virtual void Add(UIElement control)
        {
            int rows = _grid.RowDefinitions.Count;
            _grid.RowDefinitions.Add(new RowDefinition());

            var textBlock = new TextBlock
            {
                Text = ListItemPrefix,
                Margin = new Thickness(0, 5, 0, 5),
                HorizontalAlignment = HorizontalAlignment.Center
            };
            Grid.SetColumn(textBlock, 0);
            Grid.SetRow(textBlock, rows);
            _grid.Children.Add(textBlock);

            if ((control is FrameworkElement) == false)
            {
                // UIElement can set column and row,
                // so use a border.
                var border = new Border
                {
                    Child = control
                };
                control = border;
            }
            Grid.SetColumn((FrameworkElement)control, 1);
            Grid.SetRow((FrameworkElement)control, rows);
            _grid.Children.Add(control);
        }

        public InputEvents(CoreWindow window, UIElement inputElement, TouchQueue touchQueue)
        {
            _touchQueue = touchQueue;

            // The key events are always tied to the window as those will
            // only arrive here if some other control hasn't gotten it.
            window.KeyDown += CoreWindow_KeyDown;
            window.KeyUp += CoreWindow_KeyUp;
            window.VisibilityChanged += CoreWindow_VisibilityChanged;

            if (inputElement != null)
            {
                // If we have an input UIElement then we bind input events
                // to it else we'll get events for overlapping XAML controls.
                inputElement.PointerPressed += UIElement_PointerPressed;
                inputElement.PointerReleased += UIElement_PointerReleased;
                inputElement.PointerCanceled += UIElement_PointerReleased;
                inputElement.PointerMoved += UIElement_PointerMoved;
                inputElement.PointerWheelChanged += UIElement_PointerWheelChanged;
            }
            else
            {
                // If we only have a CoreWindow then use it for input events.
                window.PointerPressed += CoreWindow_PointerPressed;
                window.PointerReleased += CoreWindow_PointerReleased;
                window.PointerMoved += CoreWindow_PointerMoved;
                window.PointerWheelChanged += CoreWindow_PointerWheelChanged;
            }
        }