C# Forms.BoxView类代码示例

		public MainPageCS ()
		{
			ItemTemplate = new DataTemplate (() => {
				var nameLabel = new Label {
					FontSize = Device.GetNamedSize (NamedSize.Medium, typeof(Label)),
					HorizontalOptions = LayoutOptions.Center
				};
				nameLabel.SetBinding (Label.TextProperty, "Name");

				var colorBoxView = new BoxView {
					WidthRequest = 200,
					HeightRequest = 200,
					HorizontalOptions = LayoutOptions.Center,
					VerticalOptions = LayoutOptions.CenterAndExpand
				};
				colorBoxView.SetBinding (BoxView.ColorProperty, "Color");

				return new ContentPage {
					Padding = new Thickness (0, Device.OnPlatform (40, 40, 0), 0, 0),
					Content = new StackLayout {
						Children = {
							nameLabel,
							colorBoxView
						}
					}
				};
			});

			ItemsSource = ColorsDataModel.All;
		}

			public TealTemplate ()
			{
				RowDefinitions.Add (new RowDefinition { Height = new GridLength (0.1, GridUnitType.Star) });
				RowDefinitions.Add (new RowDefinition { Height = new GridLength (0.8, GridUnitType.Star) });
				RowDefinitions.Add (new RowDefinition { Height = new GridLength (0.1, GridUnitType.Star) });
				ColumnDefinitions.Add (new ColumnDefinition { Width = new GridLength (0.05, GridUnitType.Star) });
				ColumnDefinitions.Add (new ColumnDefinition { Width = new GridLength (0.95, GridUnitType.Star) });

				var topBoxView = new BoxView { Color = Color.Teal };
				Children.Add (topBoxView, 0, 0);
				Grid.SetColumnSpan (topBoxView, 2);

				var topLabel = new Label {
					TextColor = Color.White,
					VerticalOptions = LayoutOptions.Center
				};
				topLabel.SetBinding (Label.TextProperty, new TemplateBinding ("Parent.HeaderText"));
				Children.Add (topLabel, 1, 0);

				var contentPresenter = new ContentPresenter ();
				Children.Add (contentPresenter, 0, 1);
				Grid.SetColumnSpan (contentPresenter, 2);

				var bottomBoxView = new BoxView { Color = Color.Teal };
				Children.Add (bottomBoxView, 0, 2);
				Grid.SetColumnSpan (bottomBoxView, 2);

				var bottomLabel = new Label {
					TextColor = Color.White,
					VerticalOptions = LayoutOptions.Center
				};
				bottomLabel.SetBinding (Label.TextProperty, new TemplateBinding ("Parent.FooterText"));
				Children.Add (bottomLabel, 1, 2);
			}

        public BoxViewDemoPage()
        {
            Label header = new Label
            {
                Text = "BoxView",
                Font = Font.BoldSystemFontOfSize(50),
                HorizontalOptions = LayoutOptions.Center
            };

            BoxView boxView = new BoxView
            {
                Color = Color.Accent,
                WidthRequest = 150,
                HeightRequest = 150,
                HorizontalOptions = LayoutOptions.Center,
                VerticalOptions = LayoutOptions.CenterAndExpand
            };

            // Accomodate iPhone status bar.
            this.Padding = new Thickness(10, Device.OnPlatform(20, 0, 0), 10, 5);

            // Build the page.
            this.Content = new StackLayout
            {
                Children = 
                {
                    header,
                    boxView
                }
            };
        }

		public StackLayoutDemoCode ()
		{
			Title = "StackLayout Demo - C#";
			layout = new StackLayout { Spacing = 0 };
			StackChangeButton = new Button {
				Text = "Spacing: 0",
				FontSize = 20,
				VerticalOptions = LayoutOptions.Start,
				HorizontalOptions = LayoutOptions.FillAndExpand
			};
			StackChangeButton.Clicked += StackChangeButton_Clicked;
			BoxView yellowBox = new BoxView {
				VerticalOptions = LayoutOptions.FillAndExpand,
				HorizontalOptions = LayoutOptions.FillAndExpand,
				Color = Color.Yellow
			};
			BoxView greenBox = new BoxView {
				VerticalOptions = LayoutOptions.FillAndExpand,
				HorizontalOptions = LayoutOptions.FillAndExpand,
				Color = Color.Green
			};
			BoxView blueBox = new BoxView {
				VerticalOptions = LayoutOptions.End,
				HorizontalOptions = LayoutOptions.FillAndExpand,
				Color = Color.Blue,
				HeightRequest = 75
			};
			layout.Children.Add (StackChangeButton);
			layout.Children.Add (yellowBox);
			layout.Children.Add (greenBox);
			layout.Children.Add (blueBox);
			Content = layout;
		}

            public AquaTemplate()
            {
                RowDefinitions.Add (new RowDefinition { Height = new GridLength (0.1, GridUnitType.Star) });
                RowDefinitions.Add (new RowDefinition { Height = new GridLength (0.8, GridUnitType.Star) });
                RowDefinitions.Add (new RowDefinition { Height = new GridLength (0.1, GridUnitType.Star) });
                ColumnDefinitions.Add (new ColumnDefinition { Width = new GridLength (0.05, GridUnitType.Star) });
                ColumnDefinitions.Add (new ColumnDefinition { Width = new GridLength (0.95, GridUnitType.Star) });

                var topBoxView = new BoxView { Color = Color.Aqua };
                Children.Add (topBoxView, 0, 0);
                Grid.SetColumnSpan (topBoxView, 2);

                var topLabel = new Label {
                    Text = "Control Template Demo App",
                    TextColor = Color.Blue,
                    VerticalOptions = LayoutOptions.Center
                };
                Children.Add (topLabel, 1, 0);

                var contentPresenter = new ContentPresenter ();
                Children.Add (contentPresenter, 0, 1);
                Grid.SetColumnSpan (contentPresenter, 2);

                var bottomBoxView = new BoxView { Color = Color.Aqua };
                Children.Add (bottomBoxView, 0, 2);
                Grid.SetColumnSpan (bottomBoxView, 2);

                var bottomLabel = new Label {
                    Text = "(c) Xamarin 2016",
                    TextColor = Color.Blue,
                    VerticalOptions = LayoutOptions.Center
                };
                Children.Add (bottomLabel, 1, 2);
            }

        public ChessboardDynamicPage()
        {
            absoluteLayout = new AbsoluteLayout
            {
                BackgroundColor = Color.FromRgb(240, 220, 130),
                HorizontalOptions = LayoutOptions.Center,
                VerticalOptions = LayoutOptions.Center
            };

            for (int i = 0; i < 32; i++)
            {
                BoxView boxView = new BoxView
                {
                    Color = Color.FromRgb(0, 64, 0)
                };
                absoluteLayout.Children.Add(boxView);
            }

            ContentView contentView = new ContentView
            {
                Content = absoluteLayout
            };
            contentView.SizeChanged += OnContentViewSizeChanged;

            this.Padding = new Thickness(5, Device.OnPlatform(25, 5, 5), 5, 5);
            this.Content = contentView;
        }

        //View
        public BoxViewDemoPage()
        {
            var heading = new Label
            {
                Text = "BoxView",
                HorizontalOptions = LayoutOptions.Center,
                VerticalOptions = LayoutOptions.StartAndExpand,
                FontSize = 50,
                FontAttributes = FontAttributes.Bold | FontAttributes.Italic
            };

            var boxView = new BoxView
            {
                Color = Color.Red,
                WidthRequest = 150,
                HeightRequest = 150,
                HorizontalOptions = LayoutOptions.Center,
                VerticalOptions = LayoutOptions.CenterAndExpand
            };

            var mainLayout = new StackLayout
            {
                Children =
                {
                    heading,
                    boxView
                }
            };

            Content = mainLayout;
        }

        public OrderListHeaderView()
        {
            HeightRequest = Sizes.LargeRowHeight;

            #region add new order image
            AddNewOrderImage = new Image()
            {
                Aspect = Aspect.AspectFit
            };
            Device.OnPlatform(
                iOS: () => AddNewOrderImage.Source = new FileImageSource(){ File = "add_ios_blue" }, 
                Android: () => AddNewOrderImage.Source = new FileImageSource() { File = "add_android_blue" }
            );

            AddNewOrderImage.IsVisible = Device.OS != TargetPlatform.Android;
            #endregion

            #region add new order label
            AddNewOrderTextLabel = new Label
            {
                Text = TextResources.Customers_Orders_NewOrder.ToUpper(),
                TextColor = Palette._004,
                XAlign = TextAlignment.Start,
                YAlign = TextAlignment.Center,
            };
            #endregion

            #region compose view hierarchy
            BoxView bottomBorder = new BoxView() { BackgroundColor = Palette._013, HeightRequest = 1 };

            const double imagePaddingPercent = .35;

            RelativeLayout relativeLayout = new RelativeLayout();

            relativeLayout.Children.Add(
                view: AddNewOrderImage,
                yConstraint: Constraint.RelativeToParent(parent => parent.Height * imagePaddingPercent),
                xConstraint: Constraint.RelativeToParent(parent => parent.Height * imagePaddingPercent),
                widthConstraint: Constraint.RelativeToParent(parent => parent.Height - (parent.Height * imagePaddingPercent * 2)),
                heightConstraint: Constraint.RelativeToParent(parent => parent.Height - (parent.Height * imagePaddingPercent * 2)));

            relativeLayout.Children.Add(
                view: AddNewOrderTextLabel,
                xConstraint: Constraint.RelativeToView(AddNewOrderImage, (parent, view) => view.X + (view.Width / 2) + parent.Height * imagePaddingPercent),
                widthConstraint: Constraint.RelativeToView(AddNewOrderImage, (parent, view) => parent.Width - view.Width),
                heightConstraint: Constraint.RelativeToParent(parent => parent.Height)
            );

            relativeLayout.Children.Add(
                view: bottomBorder,
                yConstraint: Constraint.RelativeToParent(parent => parent.Height - 1),
                widthConstraint: Constraint.RelativeToParent(parent => parent.Width),
                heightConstraint: Constraint.Constant(1)
            );
            #endregion

           
            Content = relativeLayout;

        }

		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;
		}

		public RelativeLayoutDemoCode ()
		{
			Title = "Relative Layout Demo - C#";
			outerLayout = new AbsoluteLayout ();
			layout = new RelativeLayout ();
			centerLabel = new Label { FontSize = 20, Text = "RelativeLayout Demo"};
			buttonLayout = new AbsoluteLayout ();
			box = new BoxView { Color = Color.Blue, HeightRequest = 50, WidthRequest = 50 };
			layout.Children.Add (box, Constraint.RelativeToParent ((parent) => {
				return (parent.Width * .5) - 50;
			}), Constraint.RelativeToParent ((parent) => {
				return (parent.Height * .1) - 50;
			}));
			layout.Children.Add (centerLabel, Constraint.RelativeToParent ((parent) => {
				return (parent.Width * .5) - 50;
			}), Constraint.RelativeToParent ((parent) => {
				return (parent.Height * .5) - 50;
			}));
			moveButton = new Button { BackgroundColor = Color.White, FontSize = 20, TextColor = Color.Lime, Text = "Move", BorderRadius = 0};
			buttonLayout.Children.Add (moveButton, new Rectangle(0,1,1,1), AbsoluteLayoutFlags.All);
			outerLayout.Children.Add (layout, new Rectangle(0,0,1,1), AbsoluteLayoutFlags.All);
			outerLayout.Children.Add (buttonLayout, new Rectangle(0,1,1,50), AbsoluteLayoutFlags.PositionProportional|AbsoluteLayoutFlags.WidthProportional);

			moveButton.Clicked += MoveButton_Clicked;
			x = 0f;
			y = 0f;
			Content = outerLayout;
		}

        public BoxViewDemoPage()
        {
            Label header = new Label
            {
                Text = "BoxView",
                Font = Font.SystemFontOfSize(50, FontAttributes.Bold),
                HorizontalOptions = LayoutOptions.Center
            };

            BoxView boxView = new BoxView
            {
                Color = Color.Accent,
                WidthRequest = 150,
                HeightRequest = 150,
                HorizontalOptions = LayoutOptions.Center,
                VerticalOptions = LayoutOptions.CenterAndExpand
            };

            // Build the page.
            this.Content = new StackLayout
            {
                Children = 
                {
                    header,
                    boxView
                }
            };
        }

		public TaskItemCell ()
		{
			var label = new Label {
				YAlign = TextAlignment.Center
			};
			var stripe = new BoxView {
				Color = Color.Red
			};
			label.SetBinding (Label.TextProperty, new Binding ("Name"));
			stripe.SetBinding (BoxView.IsVisibleProperty, new Binding ("Completed"));

			var layout = new RelativeLayout {
				HorizontalOptions = LayoutOptions.StartAndExpand,
				VerticalOptions = LayoutOptions.StartAndExpand
			};
			layout.Children.Add (
				label, 
				Constraint.RelativeToParent (p => 20),
				Constraint.RelativeToParent (p => 0),
				Constraint.RelativeToParent (p => p.Width - 40),
				Constraint.RelativeToParent (p => p.Height));
			layout.Children.Add (
				stripe, 
				Constraint.RelativeToParent (p => 10),
				Constraint.RelativeToParent (p => (p.Height / 2) - 1),
				Constraint.RelativeToParent (p => p.Width - 20),
				Constraint.RelativeToParent (p => 2));
			View = layout;
		}

        public GridBarChartPage()
        {
            InitializeComponent();

            List<View> views = new List<View>();
            TapGestureRecognizer tapGesture = new TapGestureRecognizer();
            tapGesture.Tapped += OnBoxViewTapped;

            // Create BoxView elements and add to List.
            for (int i = 0; i < COUNT; i++)
            {
                BoxView boxView = new BoxView
                {
                    Color = Color.Accent,
                    HeightRequest = 300 * random.NextDouble(),
                    VerticalOptions = LayoutOptions.End,
                    StyleId = RandomNameGenerator()
                };
                boxView.GestureRecognizers.Add(tapGesture);
                views.Add(boxView);
            }

            // Add whole List of BoxView elements to Grid.
            grid.Children.AddHorizontal(views);

            // Start a timer at the frame rate.
            Device.StartTimer(TimeSpan.FromMilliseconds(15), OnTimerTick);
        }

        public NetworkStatusPage()
        {
            var networkLabel = new Label {
                Text = "Network Status",
                YAlign = TextAlignment.Center
            };
            var networkBox = new BoxView {
                Color = Color.White,
                HeightRequest = 25,
                WidthRequest = 25
            };

            var networkStack = new StackLayout {
                Orientation = StackOrientation.Horizontal,
                Padding = 15,
                Spacing = 25,
                Children = { networkLabel, networkBox }
            };

            var button = new Button {
                Text = "Update Status",
                HorizontalOptions = LayoutOptions.FillAndExpand
            };

            button.Clicked += (sender, e) => {
                var service = DependencyService.Get<INetworkService>();
                var isConnected = service.IsConnected();

                networkBox.Color = isConnected ? Color.Green : Color.Red;
            };

            Content = new StackLayout {
                Children = { networkStack, button }
            };
        }

        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;
        }