C# AbsoluteLayout类代码示例

 private void InitializeComponent() {
     this.LoadFromXaml(typeof(StandingsView));
     NameGrid = this.FindByName<Grid>("NameGrid");
     MessagesLayoutFrame = this.FindByName<AbsoluteLayout>("MessagesLayoutFrame");
     MessagesLayoutFrameInner = this.FindByName<ContentView>("MessagesLayoutFrameInner");
     MessagesListView = this.FindByName<ListView>("MessagesListView");
 }

        public ClockPage()
        {
            AbsoluteLayout absoluteLayout = new AbsoluteLayout();

            for (int i = 0; i < tickMarks.Length; i++)
            {
                tickMarks[i] = new BoxView
                {
                    Color = Color.Accent
                };
                absoluteLayout.Children.Add(tickMarks[i]);
            }

            absoluteLayout.Children.Add(hourHand =
                new BoxView
                {
                    Color = Color.Accent
                });
            absoluteLayout.Children.Add(minuteHand =
                new BoxView
                {
                    Color = Color.Accent
                });
            absoluteLayout.Children.Add(secondHand =
                new BoxView
                {
                    Color = Color.Red
                });

            Content = absoluteLayout;

            Device.StartTimer(TimeSpan.FromMilliseconds(16), OnTimerTick);
            SizeChanged += OnPageSizeChanged;
        }

        public CircularTextPage()
        {
            // Create the AbsoluteLayout.
            absoluteLayout = new AbsoluteLayout();
            absoluteLayout.SizeChanged += (sender, args) =>
                {
                    LayOutLabels();
                };
            Content = absoluteLayout;

            // Create the Labels.
            string text = "Xamarin.Forms makes me want to code more with ";
            labels = new Label[text.Length];
            double fontSize = 1.5 * Device.GetNamedSize(NamedSize.Large, typeof(Label));
            int countSized = 0;

            for (int index = 0; index < text.Length; index++)
            {
                char ch = text[index];

                Label label = new Label
                {
                    Text = ch == ' ' ? "\u00A0" : ch.ToString(),
                    FontSize = fontSize,
                };
                label.SizeChanged += (sender, args) =>
                    {
                        if (++countSized >= labels.Length)
                            LayOutLabels();
                    };

                labels[index] = label;
                absoluteLayout.Children.Add(label);
            }
        }

		protected override void InitializeCell ()
		{
			var width = CellWidth;
			var height = CellHeight;

			_titleLabel = new Label ();

			AbsoluteLayout simpleLayout = new AbsoluteLayout {
				VerticalOptions = LayoutOptions.FillAndExpand,
				WidthRequest = CellWidth,
				HeightRequest = CellHeight,
			};

			_image = new FastImage () {
				Aspect = Aspect.AspectFill,
				BackgroundColor = Color.Black,
			};

			_titleLabel = new Label {
				Text = "",
				TextColor = Color.White,
				FontSize = 14,
				XAlign = TextAlignment.Center,
				YAlign = TextAlignment.Center,
				LineBreakMode = LineBreakMode.TailTruncation,
				BackgroundColor = Color.FromHex ("#272727"),
			};

			simpleLayout.Children.Add (_image, new Rectangle (0, 0, width, height - 30));
			simpleLayout.Children.Add (_titleLabel, new Rectangle (0, height - 30, width, 30));
			View = simpleLayout;
		}

        public OptionsContentCell()
        {
            var labelName = new Label
            {
                Text = "Texto principal",
                TextColor = Color.Black,
                FontSize = Device.GetNamedSize(NamedSize.Medium, typeof(Label)),
                VerticalOptions = LayoutOptions.CenterAndExpand,
                HorizontalOptions = LayoutOptions.StartAndExpand,
                FontFamily = Device.OnPlatform("GillSans", "Quattrocento Sans", "Comic Sans MS")
            };
            labelName.SetBinding(Label.TextProperty, "Text");

            StackLayout stack = new StackLayout
            {
                Orientation = StackOrientation.Horizontal,
                VerticalOptions = LayoutOptions.FillAndExpand,
                HorizontalOptions = LayoutOptions.FillAndExpand,
                Padding = new Thickness(5, 0, 0, 0),
                Children = { labelName }
            };

            var absoluteLayout = new AbsoluteLayout();
            var background = new Image
            {
                Style = Styles.CellBackground
            };

            absoluteLayout.Children.Add(background, new Rectangle(0, 0, 1, 1), AbsoluteLayoutFlags.All);
            absoluteLayout.Children.Add(stack, new Rectangle(0, 0, 1, 1), AbsoluteLayoutFlags.All);

            View = absoluteLayout;
        }

        public AbsoluteLayoutExample()
        {
            Label red = new Label
                        {
                            Text = "Stop",
                            BackgroundColor = Color.Red,
                            FontSize = 20,
                            WidthRequest = 200,
                            HeightRequest = 30
                        };
            Label yellow = new Label
                           {
                               Text = "Slow down",
                               BackgroundColor = Color.Yellow,
                               FontSize = 20,
                               WidthRequest = 160,
                               HeightRequest = 160
                           };
            Label green = new Label
                          {
                              Text = "Go",
                              BackgroundColor = Color.Green,
                              FontSize = 20,
                              WidthRequest = 50,
                              HeightRequest = 50
                          };
            AbsoluteLayout absLayout = new AbsoluteLayout();
            absLayout.Children.Add(red, new Point(20, 20));
            absLayout.Children.Add(yellow, new Point(40, 60));
            absLayout.Children.Add(green, new Point(80, 180));

            Content = absLayout;
        }

		public AbsoluteLayoutPageCode ()
		{
			Title = "AbsoluteLayout - C#";
			BackgroundImage = "deer.jpg";
			var outerLayout = new AbsoluteLayout ();
			var scroll = new ScrollView ();
			outerLayout.Children.Add (scroll, new Rectangle (0, 0, 1, 1), AbsoluteLayoutFlags.All);
			outerLayout.Children.Add (new Button {
				Text = "Previous",
				BackgroundColor = Color.White,
				TextColor = Color.Green,
				BorderRadius = 0
			}, new Rectangle (0, 1, .5, 60), AbsoluteLayoutFlags.PositionProportional | AbsoluteLayoutFlags.WidthProportional);
			outerLayout.Children.Add (new Button {
				Text = "Next",
				BackgroundColor = Color.White,
				TextColor = Color.Green,
				BorderRadius = 0
			}, new Rectangle (1, 1, .5, 60), AbsoluteLayoutFlags.PositionProportional | AbsoluteLayoutFlags.WidthProportional);
			var innerLayout = new AbsoluteLayout ();
			scroll.Content = innerLayout;
			innerLayout.Children.Add (new Image { Source = "deer.jpg" }, new Rectangle (.5, 0, 300, 300), AbsoluteLayoutFlags.PositionProportional);
			innerLayout.Children.Add (new BoxView { Color = Color.FromHex ("#CC1A7019") }, new Rectangle (.5, 300, .7, 50), AbsoluteLayoutFlags.XProportional | AbsoluteLayoutFlags.WidthProportional);
			innerLayout.Children.Add (new Label { Text = "deer.jpg", XAlign = TextAlignment.Center, TextColor = Color.White }, new Rectangle (.5, 310, 1, 50), AbsoluteLayoutFlags.XProportional | AbsoluteLayoutFlags.WidthProportional);
			Content = outerLayout;
		}

        public GerenciarFeriadosView(GerenciarFeriadosViewModel viewModel)
        {

            Title = "Feriados";
            BindingContext = viewModel;
            this.SetBinding(ContentPage.NavigationProperty, "Navigation", BindingMode.TwoWay);
            // message.SetBinding(Label.IsVisibleProperty, "messageVisibility", BindingMode.TwoWay);
            listViewHolidays.SetBinding(ListView.ItemsSourceProperty, "holidays", BindingMode.TwoWay);
            listViewHolidays.ItemTemplate = new DataTemplate(typeof(TwoColumnsGridCell));
            listViewHolidays.ItemTapped += listViewHolidays_ItemTapped;

            FloatButton.AnimateWithAction();
            FloatButton.Command = new Command(toolbarAddHoliday);
            /*ToolbarItems.Add(new ToolbarItem
            {
                Icon = Images.Add2,
                Order = ToolbarItemOrder.Primary,
                Command = new Command(toolbarAddHoliday)
            });*/

            iconStack = new StackLayout
            {
                VerticalOptions = LayoutOptions.CenterAndExpand,
                HorizontalOptions = LayoutOptions.CenterAndExpand,
                Children = { iconMsg, message }
            };

            stack = new StackLayout
            {
                Padding = new Thickness(0, 15, 0, 0),
                VerticalOptions = LayoutOptions.FillAndExpand,
                HorizontalOptions = LayoutOptions.FillAndExpand,
                BackgroundColor = Color.FromHex("#ECEFF1"),
                Children = { listViewHolidays }
            };

            var absoluteLayout = new AbsoluteLayout
            {
                VerticalOptions = LayoutOptions.FillAndExpand,
            };
            //var background = new Image { Source = Images.Background, Aspect = Aspect.Fill };

            //absoluteLayout.Children.Add (background, new Rectangle (0, 0, 1, 1), AbsoluteLayoutFlags.All);
            //AbsoluteLayout.SetLayoutFlags(background, AbsoluteLayoutFlags.All);
            //AbsoluteLayout.SetLayoutBounds(background, new Rectangle(0, 0, 1, 1));

            //absoluteLayout.Children.Add (stack, new Rectangle (0, 0, 1, 1), AbsoluteLayoutFlags.All);
            AbsoluteLayout.SetLayoutFlags(stack, AbsoluteLayoutFlags.All);
            AbsoluteLayout.SetLayoutBounds(stack, new Rectangle(0, 0, 1, 1));

            //absoluteLayout.Children.Add (Add, new Rectangle (0.85, 0.85, 0.185, 0.1), AbsoluteLayoutFlags.All);
            AbsoluteLayout.SetLayoutFlags(FloatButton, AbsoluteLayoutFlags.PositionProportional);
            AbsoluteLayout.SetLayoutBounds(FloatButton, new Rectangle(0.99f, 0.98f, AbsoluteLayout.AutoSize, AbsoluteLayout.AutoSize));

            //absoluteLayout.Children.Add(background);
            absoluteLayout.Children.Add(stack);
            absoluteLayout.Children.Add(FloatButton);

            Content = absoluteLayout;
        }

		public RotateAnimationWithAnchorsPageCS ()
		{
			Title = "Rotate Animation with Anchors";

			image = new Image { Source = ImageSource.FromFile ("monkey.png"), VerticalOptions = LayoutOptions.EndAndExpand };
			startButton = new Button { Text = "Start Animation", VerticalOptions = LayoutOptions.End };
			cancelButton = new Button { Text = "Cancel Animation", IsEnabled = false };

			image.SizeChanged += OnImageSizeChanged;
			startButton.Clicked += OnStartAnimationButtonClicked;
			cancelButton.Clicked += OnCancelAnimationButtonClicked;

			absoluteLayout = new AbsoluteLayout ();
			absoluteLayout.Children.Add (image);

			var stackLayout = new StackLayout {
				Children = {
					startButton,
					cancelButton
				}
			};

			var grid = new Grid { 
				RowDefinitions = {
					new RowDefinition { Height = new GridLength (0.8, GridUnitType.Star) },
					new RowDefinition { Height = new GridLength (0.2, GridUnitType.Star) }
				},
				Children = {
					absoluteLayout,
				}
			};

			grid.Children.Add (stackLayout, 0, 1);
			Content = grid;
		}

		public MyAbsoluteLayout ()
		{
			var red = new Label {
				Text = "Stop", 
				BackgroundColor = Color.Red,
				Font = Font.SystemFontOfSize (20), 
				WidthRequest = 200, HeightRequest = 30
			};
			var yellow = new Label {
				Text = "Slow down", 
				BackgroundColor = Color.Yellow,
				Font = Font.SystemFontOfSize (20),
				 WidthRequest = 160, HeightRequest = 160
			};
			var green = new Label {
				Text = "Go", 
				BackgroundColor = Color.Green,
				Font = Font.SystemFontOfSize (20),
				WidthRequest = 50, HeightRequest = 50
			};

			var absLayout = new AbsoluteLayout ();
			absLayout.Children.Add (red, new Point (20, 20));
			absLayout.Children.Add (yellow, new Point (40, 60));
			absLayout.Children.Add (green, new Point (80, 180));

			Content = absLayout;
		}

        public AboutPage()
        {
            Title = "Informacoes";
            //			GetValue ();

            var stack = new StackLayout {

                VerticalOptions = LayoutOptions.FillAndExpand,
                Children = {
                    lbInformation
                }
            };

            var scroll = new ScrollView {
                BackgroundColor = Colors.BackgroundDefault,
                Content = stack
            };

            var absoluteLayout = new AbsoluteLayout ();
            var background = new Image {
                Style = Styles.BackgroundImage
            };

            absoluteLayout.Children.Add (background, new Rectangle (0, 0, 1, 1), AbsoluteLayoutFlags.All);
            absoluteLayout.Children.Add (scroll, new Rectangle (0, 0, 1, 1), AbsoluteLayoutFlags.All);

            Content = absoluteLayout;
        }

		public AbsoluteLayoutExplorationCode ()
		{
			Title = "Absolute Layout Exploration - C#";
			var layout = new AbsoluteLayout();

			var centerLabel = new Label {Text = "I'm centered on iPhone 4 but no other device.", LineBreakMode = LineBreakMode.WordWrap, FontSize = 20};

			AbsoluteLayout.SetLayoutBounds (centerLabel, new Rectangle (115, 159, 100, 100));
			// it is not necessary to set layout flags because absolute positioning is the default

			var bottomLabel = new Label { Text = "I'm bottom center on every device.", LineBreakMode = LineBreakMode.WordWrap };
			AbsoluteLayout.SetLayoutBounds (bottomLabel, new Rectangle (.5, 1, .5, .1));
			AbsoluteLayout.SetLayoutFlags (bottomLabel, AbsoluteLayoutFlags.All);

			var rightBox = new BoxView{ Color = Color.Olive };
			AbsoluteLayout.SetLayoutBounds (rightBox, new Rectangle (1, .5, 25, 100));
			AbsoluteLayout.SetLayoutFlags (rightBox, AbsoluteLayoutFlags.PositionProportional);

			var leftBox = new BoxView{ Color = Color.Red };
			AbsoluteLayout.SetLayoutBounds (leftBox, new Rectangle (0, .5, 25, 100));
			AbsoluteLayout.SetLayoutFlags (leftBox, AbsoluteLayoutFlags.PositionProportional);

			var topBox = new BoxView{ Color = Color.Blue };
			AbsoluteLayout.SetLayoutBounds (topBox, new Rectangle (.5, 0, 100, 25));
			AbsoluteLayout.SetLayoutFlags (topBox, AbsoluteLayoutFlags.PositionProportional);

			layout.Children.Add (bottomLabel);
			layout.Children.Add (centerLabel);
			layout.Children.Add (rightBox);
			layout.Children.Add (leftBox);
			layout.Children.Add (topBox);

			Content = layout;
		}

		protected override void Init ()
		{
			AbsoluteLayout layout = new AbsoluteLayout {
				HorizontalOptions = LayoutOptions.FillAndExpand,
				VerticalOptions = LayoutOptions.FillAndExpand,
			};

			BackgroundColor = Color.FromUint (0xFFDBDBDB);

			_btnLogin = new Button {
				HorizontalOptions = LayoutOptions.FillAndExpand,

				Text = "Press me",
				BackgroundColor = Color.FromUint (0xFF6E932D),
				TextColor = Color.White,
			};
			_btnLogin.Clicked += BtnLogin_Clicked;
			layout.Children.Add (_btnLogin, new Rectangle (0.5f, 0.5f, 0.25f, 0.25f), AbsoluteLayoutFlags.All);

			_busyBackground = new BoxView {
				BackgroundColor = new Color (0, 0, 0, 0.5f),
				IsVisible = false,
				InputTransparent = false
			};
			layout.Children.Add (_busyBackground, new Rectangle (0, 0, 1, 1), AbsoluteLayoutFlags.SizeProportional);

			Content = layout;
		}

		/// <summary>
		/// Initializes a new instance of the <see cref="DLToolkit.Forms.Controls.FlowListViewInternalCell"/> class.
		/// </summary>
		/// <param name="flowListViewRef">Flow list view reference.</param>
		public FlowListViewInternalCell(WeakReference<FlowListView> flowListViewRef)
		{
			_flowListViewRef = flowListViewRef;
			FlowListView flowListView = null;
			flowListViewRef.TryGetTarget(out flowListView);
			_useGridAsMainRoot = !flowListView.FlowUseAbsoluteLayoutInternally;

			if (!_useGridAsMainRoot)
			{
				_rootLayout = new AbsoluteLayout()
				{
					Padding = 0d,
					BackgroundColor = flowListView.FlowRowBackgroundColor,
				};
				View = _rootLayout;
			}
			else
			{
				_rootLayoutAuto = new Grid()
				{
					RowSpacing = 0d,
					ColumnSpacing = 0d,
					Padding = 0d,
					BackgroundColor = flowListView.FlowRowBackgroundColor,
				};
				View = _rootLayoutAuto;
			}

			_flowColumnTemplate = flowListView.FlowColumnTemplate;
			_desiredColumnCount = flowListView.DesiredColumnCount;
			_flowColumnExpand = flowListView.FlowColumnExpand;
		}

		public StackLayoutAbsolute ()
		{
			AbsoluteLayout absoluteLayout = new AbsoluteLayout 
			{
				VerticalOptions = LayoutOptions.FillAndExpand
			};

			Label firstlabel = new Label 
			{
				Text = "FirstLabel"
			};

			Label secondlabel = new Label 
			{
				Text = "SecondLabel"
			};


			absoluteLayout.Children.Add (secondlabel);
			AbsoluteLayout.SetLayoutFlags (secondlabel,
				AbsoluteLayoutFlags.PositionProportional);
			AbsoluteLayout.SetLayoutBounds (secondlabel,
				new Rectangle (0, 1, AbsoluteLayout.AutoSize, AbsoluteLayout.AutoSize));



			absoluteLayout.Children.Add (firstlabel);
			AbsoluteLayout.SetLayoutFlags (firstlabel,
				AbsoluteLayoutFlags.PositionProportional);
			AbsoluteLayout.SetLayoutBounds (firstlabel,
				new Rectangle (0,0, AbsoluteLayout.AutoSize,AbsoluteLayout.AutoSize));


			this.Content = absoluteLayout;
		}