Avalonia/TestApplication/Program.cs

using Perspex;
using Perspex.Controls;
using Perspex.Diagnostics;
using Perspex.Layout;
using Perspex.Media;
using Perspex.Media.Imaging;
using Perspex.Windows;
using Splat;

namespace TestApplication
{
    class TestLogger : ILogger
    {
        public LogLevel Level
        {
            get;
            set;
        }

        public void Write(string message, LogLevel logLevel)
        {
            if ((int)logLevel < (int)Level) return;
            System.Diagnostics.Debug.WriteLine(message);
        }
    }

    class Item
    {
        public string Name { get; set; }
        public string Value { get; set; }
    }

    class Node
    {
        public Node()
        {
            this.Children = new PerspexList<Node>();
        }

        public string Name { get; set; }
        public PerspexList<Node> Children { get; set; }
    }

    class Program
    {
        private static PerspexList<Node> treeData = new PerspexList<Node>
        {
            new Node
            {
                Name = "Root 1",
                Children = new PerspexList<Node>
                {
                    new Node
                    {
                        Name = "Child 1",
                    },
                    new Node
                    {
                        Name = "Child 2",
                        Children = new PerspexList<Node>
                        {
                            new Node
                            {
                                Name = "Grandchild 1",
                            },
                            new Node
                            {
                                Name = "Grandmaster Flash",
                            },
                        }
                    },
                    new Node
                    {
                        Name = "Child 3",
                    },
                }
            },
            new Node
            {
                Name = "Root 2",
            },
        };

        static void Main(string[] args)
        {
            LogManager.Enable(new TestLogger());
            LogManager.Instance.LogLayoutMessages = true;

            App application = new App
            {
                DataTemplates = new DataTemplates
                {
                    new TreeDataTemplate<Node>(
                        x => new TextBlock { Text = x.Name },
                        x => x.Children,
                        x => true),
                },
            };

            Window window = new Window
            {
                Content = new TabControl
                {
                    Items = new[]
                    {
                        new TabItem
                        {
                            Header = "Buttons",
                            Content = new StackPanel
                            {
                                Orientation = Orientation.Vertical,
                                HorizontalAlignment = HorizontalAlignment.Center,
                                VerticalAlignment = VerticalAlignment.Center,
                                Gap = 8,
                                MinWidth = 120,
                                Children = new Controls
                                {
                                    new Button
                                    {
                                        Content = "Button",
                                    },
                                    new Button
                                    {
                                        Content = "Button",
                                        Background = new SolidColorBrush(0xcc119eda),
                                    },
                                    new CheckBox
                                    {
                                        Content = "Checkbox",
                                    },
                                }
                            },
                        },
                        new TabItem
                        {
                            Header = "Text",
                            Content = new StackPanel
                            {
                                Orientation = Orientation.Vertical,
                                HorizontalAlignment = HorizontalAlignment.Center,
                                VerticalAlignment = VerticalAlignment.Center,
                                Gap = 8,
                                Width = 120,
                                Children = new Controls
                                {
                                    new TextBlock
                                    {
                                        Text = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin venenatis dui quis libero suscipit tincidunt.",
                                    },
                                    new TextBox
                                    {
                                        Text = "Text Box",
                                    },
                                }
                            },
                        },
                        new TabItem
                        {
                            Header = "Images",
                            Content = new StackPanel
                            {
                                Orientation = Orientation.Vertical,
                                HorizontalAlignment = HorizontalAlignment.Center,
                                VerticalAlignment = VerticalAlignment.Center,
                                Gap = 8,
                                Width = 120,
                                Children = new Controls
                                {
                                    new Image
                                    {
                                        Source = new Bitmap("github_icon.png"),
                                        Width = 200,
                                    },
                                }
                            },
                        },
                        new TabItem
                        {
                            Header = "Lists",
                            Content = new StackPanel
                            {
                                Orientation = Orientation.Horizontal,
                                HorizontalAlignment = HorizontalAlignment.Center,
                                VerticalAlignment = VerticalAlignment.Center,
                                Gap = 8,
                                Children = new Controls
                                {
                                    new TreeView
                                    {
                                        Id = "treeView",
                                        Items = treeData,
                                    },
                                    new StackPanel
                                    {
                                        Orientation = Orientation.Vertical,
                                        Gap = 2.0,
                                        Children = new Controls
                                        {
                                            new TextBox
                                            {
                                                Id = "newTreeViewItemText",
                                                Text = "New Item"
                                            },
                                            new Button
                                            {
                                                Id = "addTreeViewItem",
                                                Content = "Add",
                                            },
                                        }
                                    },
                                }
                            },
                        },
                    }
                }
            };

            //var treeView = window.FindControl<TreeView>("treeView");
            //var newTreeViewItemText = window.FindControl<TextBox>("newTreeViewItemText");
            //var addTreeViewItem = window.FindControl<Button>("addTreeViewItem");

            //addTreeViewItem.Click += (s, e) =>
            //{
            //    if (treeView.SelectedItem != null)
            //    {
            //        ((Node)treeView.SelectedItem).Children.Add(new Node
            //        {
            //            Name = newTreeViewItemText.Text,
            //        });
            //    }
            //};

            window.Show();
            Application.Current.Run(window);
        }
    }
}