feat: Add Dialog styles and demo.

src/Avalonia/HandyControlDemo_Avalonia/Data/DemoInfo.json

@@ -42,6 +42,7 @@
     "group": true,
     "demoItemList": [
       [ "ConfettiCannon", "ConfettiCannonDemo", "Brush.Favorite", "", "Interacting" ],
+      [ "Dialog", "DialogDemo", "Brush.Dialog", "", "Feedback" ],
       [ "Gravatar", "GravatarDemo", "Brush.User", "", "DataDisplay" ],
       [ "ButtonGroup", "ButtonGroupDemo", "Brush.ButtonGroup", "", "Button" ],
       [ "ProgressButton", "ProgressButtonDemo", "Brush.ProgressBarStatusBar8", "", "Button" ],

src/Avalonia/HandyControlDemo_Avalonia/MainWindow.axaml.cs

@@ -1,13 +1,20 @@
 using Avalonia.Controls;
 using Avalonia.Interactivity;
+using HandyControl.Controls;
+using HandyControlDemo.Data;
 using HandyControlDemo.UserControl;
 using HandyControlDemo.ViewModel;
 
 namespace HandyControlDemo;
 
-public partial class MainWindow : Window
+public partial class MainWindow : Avalonia.Controls.Window
 {
-    public MainWindow() => InitializeComponent();
+    public MainWindow()
+    {
+        InitializeComponent();
+
+        Dialog.SetToken(this, MessageToken.MainWindow);
+    }
 
     protected override void OnLoaded(RoutedEventArgs e)
     {

src/Avalonia/HandyControlDemo_Avalonia/UserControl/Basic/InteractiveDialog.axaml

@@ -0,0 +1,22 @@
+<Border x:Class="HandyControlDemo.UserControl.InteractiveDialog"
+        xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:hc="https://handyorg.github.io/handycontrol"
+        CornerRadius="10"
+        Width="400"
+        Height="247"
+        Background="{DynamicResource RegionBrush}">
+    <StackPanel VerticalAlignment="Center"
+                Margin="32"
+                Spacing="32">
+        <TextBlock Theme="{StaticResource TextBlockLargeBold}"
+                   Text="{Binding Message}" />
+        <TextBox Text="{Binding Result, Mode=TwoWay}"
+                 Theme="{StaticResource TextBoxExtend}" />
+        <Button Width="120"
+                Command="{Binding CloseCommand}"
+                Theme="{StaticResource ButtonPrimary}"
+                HorizontalAlignment="Center"
+                Content="OK" />
+    </StackPanel>
+</Border>

src/Avalonia/HandyControlDemo_Avalonia/UserControl/Basic/InteractiveDialog.axaml.cs

@@ -0,0 +1,14 @@
+using Avalonia.Controls;
+using HandyControlDemo.ViewModel;
+
+namespace HandyControlDemo.UserControl;
+
+public partial class InteractiveDialog : Border
+{
+    public InteractiveDialog()
+    {
+        InitializeComponent();
+
+        DataContext = new InteractiveDialogViewModel();
+    }
+}

src/Avalonia/HandyControlDemo_Avalonia/UserControl/Basic/TextDialog.axaml

@@ -0,0 +1,25 @@
+<Border x:Class="HandyControlDemo.UserControl.TextDialog"
+        xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:hc="https://handyorg.github.io/handycontrol"
+        CornerRadius="10"
+        Width="400"
+        Height="247"
+        Background="{DynamicResource RegionBrush}">
+    <Panel>
+        <TextBlock Theme="{StaticResource TextBlockLargeBold}"
+                   HorizontalAlignment="Center"
+                   VerticalAlignment="Center"
+                   Text="Please wait..." />
+        <Button x:Name="CloseButton"
+                Width="22"
+                Height="22"
+                Theme="{StaticResource ButtonIcon}"
+                Foreground="{DynamicResource PrimaryBrush}"
+                hc:IconElement.Geometry="{StaticResource ErrorGeometry}"
+                Padding="0"
+                HorizontalAlignment="Right"
+                VerticalAlignment="Top"
+                Margin="0,4,4,0" />
+    </Panel>
+</Border>

src/Avalonia/HandyControlDemo_Avalonia/UserControl/Basic/TextDialog.axaml.cs

@@ -0,0 +1,15 @@
+using Avalonia.Controls;
+using Avalonia.VisualTree;
+using HandyControl.Controls;
+
+namespace HandyControlDemo.UserControl;
+
+public partial class TextDialog : Border
+{
+    public TextDialog()
+    {
+        InitializeComponent();
+
+        CloseButton.Click += (_, _) => this.FindAncestorOfType<Dialog>()?.Close();
+    }
+}

src/Avalonia/HandyControlDemo_Avalonia/UserControl/Basic/TextDialogWithTimer.axaml

@@ -0,0 +1,35 @@
+<Border x:Class="HandyControlDemo.UserControl.TextDialogWithTimer"
+        xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:hc="https://handyorg.github.io/handycontrol"
+        CornerRadius="10"
+        Width="400"
+        Height="247"
+        Background="{DynamicResource RegionBrush}">
+    <Panel>
+        <Viewbox Width="80"
+                 Height="80"
+                 HorizontalAlignment="Center"
+                 VerticalAlignment="Center">
+            <TextBlock TextWrapping="Wrap"
+                       Theme="{StaticResource TextBlockLargeBold}"
+                       Text="Please wait..." />
+        </Viewbox>
+        <Button x:Name="CloseButton"
+                Width="22"
+                Height="22"
+                Foreground="{DynamicResource PrimaryBrush}"
+                hc:IconElement.Geometry="{StaticResource ErrorGeometry}"
+                Padding="0"
+                Theme="{StaticResource ButtonIcon}"
+                HorizontalAlignment="Right"
+                VerticalAlignment="Top"
+                Margin="0,4,4,0" />
+        <hc:CircleProgressBar x:Name="ProgressBarTimer"
+                              ShowText="False"
+                              Width="120"
+                              Height="120"
+                              HorizontalAlignment="Center"
+                              VerticalAlignment="Center" />
+    </Panel>
+</Border>

src/Avalonia/HandyControlDemo_Avalonia/UserControl/Basic/TextDialogWithTimer.axaml.cs

@@ -0,0 +1,44 @@
+using System;
+using Avalonia.Controls;
+using Avalonia.Threading;
+using Avalonia.VisualTree;
+using HandyControl.Controls;
+using HandyControlDemo.ViewModel;
+
+namespace HandyControlDemo.UserControl;
+
+public partial class TextDialogWithTimer : Border
+{
+    public TextDialogWithTimer()
+    {
+        InitializeComponent();
+
+        DataContext = new InteractiveDialogViewModel();
+
+        var startTime = DateTime.Now;
+        var timer = new DispatcherTimer(DispatcherPriority.ApplicationIdle)
+        {
+            Interval = TimeSpan.FromMilliseconds(50)
+        };
+
+        timer.Tick += (_, _) =>
+        {
+            var elapsed = (DateTime.Now - startTime).TotalMilliseconds;
+            var progress = Math.Min(elapsed / 5000.0 * 100, 100);
+            ProgressBarTimer.Value = progress;
+
+            if (progress >= 100)
+            {
+                timer.Stop();
+                this.FindAncestorOfType<Dialog>()?.Close();
+            }
+        };
+        timer.Start();
+
+        CloseButton.Click += (_, _) =>
+        {
+            timer.Stop();
+            this.FindAncestorOfType<Dialog>()?.Close();
+        };
+    }
+}

src/Avalonia/HandyControlDemo_Avalonia/UserControl/Controls/DialogDemo.axaml

@@ -0,0 +1,46 @@
+<UserControl xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:hc="https://handyorg.github.io/handycontrol"
+             xmlns:vm="clr-namespace:HandyControlDemo.ViewModel"
+             xmlns:sys="clr-namespace:System;assembly=System.Runtime"
+             x:Class="HandyControlDemo.UserControl.DialogDemo"
+             DataContext="{Binding DialogDemo, Source={x:Static vm:ViewModelLocator.Instance}}"
+             Background="{DynamicResource RegionBrush}"
+             MinWidth="500">
+    <hc:DialogContainer>
+        <TransitioningContentControl>
+            <Panel>
+                <StackPanel Margin="32"
+                            VerticalAlignment="Center">
+                    <Button Content="TextDialog"
+                            Command="{Binding ShowTextCommand}" />
+                    <Button Margin="0,32,0,0"
+                            Content="TextDialog(In control)"
+                            Command="{Binding ShowTextCommand}"
+                            CommandParameter="{Binding $parent[UserControl]}" />
+                    <Button Margin="0,32,0,0"
+                            Content="TextDialog with timer"
+                            Command="{Binding ShowInteractiveDialogCommand}">
+                        <Button.CommandParameter>
+                            <sys:Boolean>True</sys:Boolean>
+                        </Button.CommandParameter>
+                    </Button>
+                    <TextBox Margin="0,32,0,0"
+                             Text="{Binding DialogResult}"
+                             Theme="{StaticResource TextBoxExtend}"
+                             Watermark="Please input..." />
+                    <Button Margin="0,10,0,0"
+                            Content="InteractiveDialog"
+                            Command="{Binding ShowInteractiveDialogCommand}">
+                        <Button.CommandParameter>
+                            <sys:Boolean>False</sys:Boolean>
+                        </Button.CommandParameter>
+                    </Button>
+                    <Button Margin="0,32,0,0"
+                            Content="New window"
+                            Command="{Binding NewWindowCommand}" />
+                </StackPanel>
+            </Panel>
+        </TransitioningContentControl>
+    </hc:DialogContainer>
+</UserControl>

src/Avalonia/HandyControlDemo_Avalonia/UserControl/Controls/DialogDemo.axaml.cs

@@ -0,0 +1,16 @@
+using HandyControl.Controls;
+using HandyControlDemo.Data;
+using HandyControlDemo.ViewModel;
+
+namespace HandyControlDemo.UserControl;
+
+public partial class DialogDemo : Avalonia.Controls.UserControl
+{
+    public DialogDemo()
+    {
+        InitializeComponent();
+
+        DataContext = ViewModelLocator.Instance.DialogDemo;
+        Dialog.SetToken(this, MessageToken.DialogContainer);
+    }
+}

src/Avalonia/HandyControlDemo_Avalonia/ViewModel/Basic/InteractiveDialogViewModel.cs

@@ -0,0 +1,20 @@
+using System;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using HandyControl.Tools.Extension;
+
+namespace HandyControlDemo.ViewModel;
+
+public partial class InteractiveDialogViewModel : ObservableObject, IDialogResultable<string>
+{
+    public Action CloseAction { get; set; }
+
+    [ObservableProperty]
+    private string _result;
+
+    [ObservableProperty]
+    private string _message;
+
+    [RelayCommand]
+    private void Close() => CloseAction?.Invoke();
+}

src/Avalonia/HandyControlDemo_Avalonia/ViewModel/Controls/DialogDemoViewModel.cs

@@ -0,0 +1,70 @@
+using System.Threading.Tasks;
+using Avalonia.Controls;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using HandyControl.Controls;
+using HandyControl.Tools.Extension;
+using HandyControlDemo.Data;
+using HandyControlDemo.UserControl;
+using HandyControlDemo.Window;
+
+namespace HandyControlDemo.ViewModel;
+
+public partial class DialogDemoViewModel : ObservableObject
+{
+    [ObservableProperty]
+    private string _dialogResult;
+
+    [RelayCommand]
+    private void ShowText(Control? element)
+    {
+        if (element == null)
+        {
+            Dialog.Show(new TextDialog());
+        }
+        else
+        {
+            Dialog.Show(new TextDialog(), MessageToken.DialogContainer);
+        }
+    }
+
+    [RelayCommand]
+    private async Task ShowInteractiveDialog(bool withTimer)
+    {
+        if (!withTimer)
+        {
+            DialogResult = await Dialog.Show<InteractiveDialog>()
+                .Initialize<InteractiveDialogViewModel>(vm => vm.Message = DialogResult)
+                .GetResultAsync<string>();
+        }
+        else
+        {
+            await Dialog.Show<TextDialogWithTimer>(MessageToken.MainWindow).GetResultAsync<string>();
+        }
+    }
+
+    [RelayCommand]
+    private void NewWindow()
+    {
+        var window = new DialogDemoWindow();
+        window.Show();
+    }
+
+    [RelayCommand]
+    private void ShowWithToken(string token)
+    {
+        if (!string.IsNullOrEmpty(token))
+        {
+            Dialog.Show(new TextDialog(), token);
+        }
+    }
+
+    [RelayCommand]
+    private void CloseMainWindowDialog(string token)
+    {
+        if (!string.IsNullOrEmpty(token))
+        {
+            Dialog.Close(token);
+        }
+    }
+}

src/Avalonia/HandyControlDemo_Avalonia/ViewModel/ViewModelLocator.cs

@@ -21,6 +21,7 @@ public class ViewModelLocator
         services.AddTransient<MainViewModel>();
         services.AddTransient<InputElementDemoViewModel>();
         services.AddTransient<CardDemoViewModel>();
+        services.AddTransient<DialogDemoViewModel>();
 
         _serviceProvider = services.BuildServiceProvider();
     }
@@ -30,4 +31,6 @@ public class ViewModelLocator
     public InputElementDemoViewModel InputElementDemo => _serviceProvider.GetService<InputElementDemoViewModel>()!;
 
     public CardDemoViewModel CardDemo => _serviceProvider.GetService<CardDemoViewModel>()!;
+
+    public DialogDemoViewModel DialogDemo => _serviceProvider.GetService<DialogDemoViewModel>()!;
 }

src/Avalonia/HandyControlDemo_Avalonia/Window/DialogDemoWindow.axaml

@@ -0,0 +1,29 @@
+<Window x:Class="HandyControlDemo.Window.DialogDemoWindow"
+        xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:hc="https://handyorg.github.io/handycontrol"
+        xmlns:vm="clr-namespace:HandyControlDemo.ViewModel"
+        xmlns:data="clr-namespace:HandyControlDemo.Data"
+        x:DataType="vm:DialogDemoViewModel"
+        DataContext="{Binding DialogDemo, Source={x:Static vm:ViewModelLocator.Instance}}"
+        Width="800"
+        Height="500"
+        Background="{DynamicResource SecondaryRegionBrush}">
+    <TransitioningContentControl>
+        <hc:UniformSpacingPanel Margin="32"
+                                VerticalAlignment="Center"
+                                HorizontalAlignment="Center"
+                                Orientation="Vertical"
+                                Spacing="10">
+            <Button Content="ShowInCurrentWindow"
+                    Command="{Binding ShowWithTokenCommand}"
+                    CommandParameter="{Binding $parent[Window].DialogToken}" />
+            <Button Content="ShowInMainWindow"
+                    Command="{Binding ShowWithTokenCommand}"
+                    CommandParameter="{x:Static data:MessageToken.MainWindow}" />
+            <Button Content="CloseMainWindowDialog"
+                    Command="{Binding CloseMainWindowDialogCommand}"
+                    CommandParameter="{x:Static data:MessageToken.MainWindow}" />
+        </hc:UniformSpacingPanel>
+    </TransitioningContentControl>
+</Window>

src/Avalonia/HandyControlDemo_Avalonia/Window/DialogDemoWindow.axaml.cs

@@ -0,0 +1,19 @@
+using System;
+using Avalonia.Controls;
+using HandyControl.Controls;
+using HandyControlDemo.Data;
+
+namespace HandyControlDemo.Window;
+
+public partial class DialogDemoWindow : Avalonia.Controls.Window
+{
+    public string DialogToken { get; }
+
+    public DialogDemoWindow()
+    {
+        InitializeComponent();
+
+        DialogToken = $"{MessageToken.DialogDemoWindow}+{DateTime.Now:yyyyMMddHHmmssfff}";
+        Dialog.SetToken(this, DialogToken);
+    }
+}

src/Avalonia/HandyControl_Avalonia/Controls/Dialog/Dialog.cs

@@ -0,0 +1,211 @@
+using System.Collections.Generic;
+using System.Linq;
+using Avalonia;
+using Avalonia.Controls;
+using Avalonia.Controls.ApplicationLifetimes;
+using Avalonia.Controls.Metadata;
+using Avalonia.Controls.Primitives;
+using Avalonia.Input;
+using Avalonia.Media;
+using Avalonia.VisualTree;
+using HandyControl.Tools;
+
+namespace HandyControl.Controls;
+
+[TemplatePart("PART_BackElement", typeof(Border))]
+public class Dialog : ContentControl
+{
+    private const string BackElement = "PART_BackElement";
+
+    private string? _token;
+    private Border? _backElement;
+    private Panel? _hostPanel;
+
+    private static readonly ControlTokenManager<Control> TokenManager = new();
+    private static readonly Dictionary<string, Dialog> DialogDict = new();
+
+    public static readonly StyledProperty<bool> IsClosedProperty =
+        AvaloniaProperty.Register<Dialog, bool>(nameof(IsClosed));
+
+    public bool IsClosed
+    {
+        get => GetValue(IsClosedProperty);
+        internal set => SetValue(IsClosedProperty, value);
+    }
+
+    public static readonly AttachedProperty<bool> MaskCanCloseProperty =
+        AvaloniaProperty.RegisterAttached<Dialog, AvaloniaObject, bool>("MaskCanClose", false);
+
+    public static void SetMaskCanClose(AvaloniaObject element, bool value) =>
+        element.SetValue(MaskCanCloseProperty, value);
+
+    public static bool GetMaskCanClose(AvaloniaObject element) =>
+        element.GetValue(MaskCanCloseProperty);
+
+    public static readonly StyledProperty<IBrush?> MaskBrushProperty =
+        AvaloniaProperty.Register<Dialog, IBrush?>(nameof(MaskBrush));
+
+    public IBrush? MaskBrush
+    {
+        get => GetValue(MaskBrushProperty);
+        set => SetValue(MaskBrushProperty, value);
+    }
+
+    public static readonly AttachedProperty<string?> TokenProperty =
+        AvaloniaProperty.RegisterAttached<Dialog, AvaloniaObject, string?>("Token");
+
+    static Dialog()
+    {
+        TokenProperty.Changed.AddClassHandler<AvaloniaObject>(TokenManager.OnTokenChanged);
+    }
+
+    public static void SetToken(AvaloniaObject element, string? value) =>
+        element.SetValue(TokenProperty, value);
+
+    public static string? GetToken(AvaloniaObject element) =>
+        element.GetValue(TokenProperty);
+
+    public static Dialog Show<T>(string? token = null) where T : new() => Show(new T(), token);
+
+    public static Dialog Show(object content, string? token = null)
+    {
+        var dialog = new Dialog
+        {
+            _token = token,
+            Content = content
+        };
+
+        if (string.IsNullOrEmpty(token))
+        {
+            var window = GetActiveWindow();
+            if (window != null)
+            {
+                ShowOnWindow(dialog, window);
+            }
+        }
+        else
+        {
+            Close(token);
+            DialogDict[token] = dialog;
+            if (TokenManager.TryGetControl(token, out var ctrl) && ctrl != null)
+            {
+                if (ctrl is Window window)
+                {
+                    ShowOnWindow(dialog, window);
+                }
+                else
+                {
+                    var panel = FindDialogContainer(ctrl);
+                    if (panel != null)
+                    {
+                        dialog._hostPanel = panel;
+                        dialog.IsClosed = false;
+                        dialog.Width = panel.Bounds.Width;
+                        dialog.Height = panel.Bounds.Height;
+                        panel.Children.Add(dialog);
+                        panel.InvalidateMeasure();
+                    }
+                    else
+                    {
+                        var win = GetActiveWindow();
+                        if (win != null)
+                            ShowOnWindow(dialog, win);
+                    }
+                }
+            }
+        }
+
+        return dialog;
+    }
+
+    private static void ShowOnWindow(Dialog dialog, Window window)
+    {
+        var overlay = OverlayLayer.GetOverlayLayer(window);
+        if (overlay == null) return;
+
+        var size = overlay.Bounds.Size;
+        if (size.Width <= 0 || size.Height <= 0)
+        {
+            var topLevel = TopLevel.GetTopLevel(overlay);
+            if (topLevel != null)
+                size = topLevel.ClientSize;
+        }
+
+        dialog._hostPanel = overlay;
+        dialog.IsClosed = false;
+        dialog.Width = size.Width;
+        dialog.Height = size.Height;
+        overlay.Children.Add(dialog);
+
+        void OnOverlayResized(object? sender, SizeChangedEventArgs e)
+        {
+            if (dialog._hostPanel == null) return;
+            dialog.Width = e.NewSize.Width;
+            dialog.Height = e.NewSize.Height;
+        }
+        overlay.SizeChanged += OnOverlayResized;
+    }
+
+    public static void Close(string? token)
+    {
+        if (!string.IsNullOrEmpty(token) && DialogDict.TryGetValue(token, out var dialog))
+        {
+            dialog.Close();
+        }
+    }
+
+    public void Close()
+    {
+        if (_hostPanel == null) return;
+
+        _hostPanel.Children.Remove(this);
+        _hostPanel = null;
+        IsClosed = true;
+
+        if (!string.IsNullOrEmpty(_token))
+        {
+            DialogDict.Remove(_token);
+        }
+    }
+
+    protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
+    {
+        base.OnApplyTemplate(e);
+
+        _backElement = e.NameScope.Find<Border>(BackElement);
+    }
+
+    protected override void OnPointerReleased(PointerReleasedEventArgs e)
+    {
+        base.OnPointerReleased(e);
+
+        if (e.InitialPressMouseButton == MouseButton.Left &&
+            GetMaskCanClose(this) && _backElement != null && _backElement.IsPointerOver)
+        {
+            Close();
+        }
+    }
+
+    private static DialogContainer? FindDialogContainer(Visual root)
+    {
+        foreach (var child in root.GetVisualChildren())
+        {
+            if (child is DialogContainer found)
+                return found;
+            var nested = FindDialogContainer(child);
+            if (nested != null)
+                return nested;
+        }
+        return null;
+    }
+
+    private static Window? GetActiveWindow()
+    {
+        if (Application.Current?.ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
+        {
+            return desktop.Windows.FirstOrDefault(w => w.IsActive) ?? desktop.MainWindow;
+        }
+
+        return null;
+    }
+}

src/Avalonia/HandyControl_Avalonia/Controls/Dialog/DialogContainer.cs

@@ -0,0 +1,8 @@
+using Avalonia.Controls;
+
+namespace HandyControl.Controls;
+
+/// <summary>
+///     A panel that can host Dialog overlays when targeted by a matching token.
+/// </summary>
+public class DialogContainer : Panel;

src/Avalonia/HandyControl_Avalonia/Themes/Styles/Dialog.axaml

@@ -0,0 +1,30 @@
+<ResourceDictionary xmlns="https://github.com/avaloniaui"
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal"
+                    xmlns:hc="clr-namespace:HandyControl.Controls">
+
+    <ControlTheme x:Key="DialogBaseStyle"
+                  TargetType="hc:Dialog">
+        <Setter Property="Focusable" Value="False" />
+        <Setter Property="HorizontalContentAlignment" Value="Center" />
+        <Setter Property="VerticalContentAlignment" Value="Center" />
+        <Setter Property="MaskBrush" Value="{DynamicResource DarkOpacityBrush}" />
+        <Setter Property="Template">
+            <ControlTemplate TargetType="hc:Dialog">
+                <Border Name="PART_BackElement"
+                        Background="{TemplateBinding MaskBrush}">
+                    <ContentPresenter Content="{TemplateBinding Content}"
+                                      ContentTemplate="{TemplateBinding ContentTemplate}"
+                                      Margin="{TemplateBinding Padding}"
+                                      HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
+                                      VerticalAlignment="{TemplateBinding VerticalContentAlignment}" />
+                </Border>
+            </ControlTemplate>
+        </Setter>
+    </ControlTheme>
+
+    <ControlTheme x:Key="{x:Type hc:Dialog}"
+                  BasedOn="{StaticResource DialogBaseStyle}"
+                  TargetType="hc:Dialog" />
+
+</ResourceDictionary>

src/Avalonia/HandyControl_Avalonia/Themes/Styles/MergedStyles.axaml

@@ -57,6 +57,7 @@
                 <MergeResourceInclude Source="avares://HandyControl/Themes/Styles/Calendar.axaml" />
                 <MergeResourceInclude Source="avares://HandyControl/Themes/Styles/CalendarDatePicker.axaml" />
                 <MergeResourceInclude Source="avares://HandyControl/Themes/Styles/DatePicker.axaml" />
+                <MergeResourceInclude Source="avares://HandyControl/Themes/Styles/Dialog.axaml" />
                 <MergeResourceInclude Source="avares://HandyControl/Themes/Styles/Clock.axaml" />
                 <MergeResourceInclude Source="avares://HandyControl/Themes/Styles/TimePicker.axaml" />
                 <MergeResourceInclude Source="avares://HandyControl/Themes/Styles/TextBox.axaml" />

src/Avalonia/HandyControl_Avalonia/Tools/Extension/DialogExtension.cs

@@ -0,0 +1,77 @@
+using System;
+using System.Threading.Tasks;
+using Avalonia.Controls;
+using Avalonia.Interactivity;
+using HandyControl.Controls;
+
+namespace HandyControl.Tools.Extension;
+
+public interface IDialogResultable<T>
+{
+    T Result { get; set; }
+
+    Action CloseAction { get; set; }
+}
+
+public static class DialogExtension
+{
+    public static Task<TResult> GetResultAsync<TResult>(this Dialog dialog)
+    {
+        var tcs = new TaskCompletionSource<TResult>();
+
+        try
+        {
+            if (dialog.IsClosed)
+            {
+                SetResult();
+            }
+            else
+            {
+                dialog.Unloaded += OnUnloaded;
+                dialog.GetViewModel<IDialogResultable<TResult>>().CloseAction = dialog.Close;
+            }
+        }
+        catch (Exception e)
+        {
+            tcs.TrySetException(e);
+        }
+
+        return tcs.Task;
+
+        void OnUnloaded(object? sender, RoutedEventArgs args)
+        {
+            dialog.Unloaded -= OnUnloaded;
+            SetResult();
+        }
+
+        void SetResult()
+        {
+            try
+            {
+                tcs.TrySetResult(dialog.GetViewModel<IDialogResultable<TResult>>().Result);
+            }
+            catch (Exception e)
+            {
+                tcs.TrySetException(e);
+            }
+        }
+    }
+
+    public static Dialog Initialize<TViewModel>(this Dialog dialog, Action<TViewModel> configure)
+    {
+        configure?.Invoke(dialog.GetViewModel<TViewModel>());
+
+        return dialog;
+    }
+
+    public static TViewModel GetViewModel<TViewModel>(this Dialog dialog)
+    {
+        if (!(dialog.Content is Control frameworkElement))
+            throw new InvalidOperationException("The dialog is not a derived class of the FrameworkElement. ");
+
+        if (!(frameworkElement.DataContext is TViewModel viewModel))
+            throw new InvalidOperationException($"The view model of the dialog is not the {typeof(TViewModel)} type or its derived class. ");
+
+        return viewModel;
+    }
+}