FluentDialogs.Wpf 1.0.0

FluentDialogs.Wpf

Injectable WPF dialog library for .NET 9. Replaces System.Windows.MessageBox with async, MVVM-compatible dialogs styled for Windows 11 Fluent Design.

What This Library Is

A dependency-injectable message box replacement for WPF applications. Provides async dialog methods, custom buttons, theming (light/dark), and extended dialog types (input, selection, license, timeout). All dialogs are modal, respect owner windows, and return strongly-typed results.

Installation

dotnet add package FluentDialogs.Wpf

Requirements: .NET 9.0+, Windows Desktop Runtime

Basic Setup

DI Registration

using FluentDialogs;
using Microsoft.Extensions.DependencyInjection;

var services = new ServiceCollection();
services.AddFluentDialogs();
var provider = services.BuildServiceProvider();

This registers:

• IMessageBoxService - Main dialog service
• IMessageBoxThemeService - Theme switching

For manual theme management:

services.AddFluentDialogsWithoutTheme();

Required Resources

Merge theme resources in App.xaml:

<Application.Resources>
    <ResourceDictionary>
        <ResourceDictionary.MergedDictionaries>
            <ResourceDictionary Source="pack://application:,,,/FluentDialogs.Wpf;component/Themes/ThemeResources.xaml"/>
            <ResourceDictionary Source="pack://application:,,,/FluentDialogs.Wpf;component/Themes/FluentLight.xaml"/>
        </ResourceDictionary.MergedDictionaries>
    </ResourceDictionary>
</Application.Resources>

Basic Usage

Inject IMessageBoxService into your ViewModel:

public class MainViewModel
{
    private readonly IMessageBoxService _messageBox;

    public MainViewModel(IMessageBoxService messageBox)
    {
        _messageBox = messageBox;
    }

    public async Task ShowInfoAsync()
    {
        await _messageBox.InfoAsync("Operation completed.", "Info");
    }

    public async Task<bool> ConfirmAsync()
    {
        var result = await _messageBox.ConfirmAsync("Delete this item?", "Confirm");
        return result == MessageBoxResult.Yes;
    }

    public async Task ShowErrorAsync(Exception ex)
    {
        await _messageBox.ErrorAsync("Operation failed.", ex);
    }
}

Available Methods

Custom Buttons

Define buttons with custom text, styles, and behavior:

var buttons = new List<MessageBoxButtonDefinition>
{
    new() { Text = "Save", Result = MessageBoxResult.Yes, Style = ButtonStyle.Primary, IsDefault = true },
    new() { Text = "Discard", Result = MessageBoxResult.No, Style = ButtonStyle.Danger },
    new() { Text = "Cancel", Result = MessageBoxResult.Cancel, IsCancel = true }
};

var options = new MessageBoxOptions
{
    Title = "Unsaved Changes",
    Message = "Save before closing?",
    Icon = MessageBoxIcon.Warning,
    CustomButtons = buttons
};

var result = await _messageBox.ShowAsync(options);

Button Properties

Constraint: Use either Buttons or CustomButtons, not both.

Custom Content

Inject any WPF content below the message:

var options = new MessageBoxOptions
{
    Title = "Settings",
    Message = "Apply changes?",
    Buttons = MessageBoxButtons.OKCancel,
    Content = new CheckBox { Content = "Remember choice" }
};

var result = await _messageBox.ShowAsync(options);

The Content property accepts any object renderable by WPF ContentPresenter.

Built-in Native Features

Use options properties instead of custom content for common scenarios:

// Checkbox
var result = await _messageBox.ConfirmWithCheckboxAsync(
    "Continue?", "Do not ask again", "Confirm");
// result.IsChecked contains checkbox state

// Input
var result = await _messageBox.InputAsync(
    "Enter name:", "Name", defaultValue: "User");
// result.InputText contains input

// Password
var result = await _messageBox.InputAsync(
    "Enter password:", "Password", isPassword: true);

// Selection
var result = await _messageBox.SelectAsync(
    "Choose option:", new[] { "A", "B", "C" });
// result.SelectedItem, result.SelectedIndex

// Hyperlink (via options)
var options = new MessageBoxOptions
{
    Message = "Click link for help.",
    HyperlinkText = "Documentation",
    HyperlinkUrl = "https://example.com"
};

Dialog Sizing

Dialogs auto-size by default. Override with explicit dimensions:

var options = new MessageBoxOptions
{
    Title = "Large Content",
    Message = longText,
    Width = 600,
    Height = 400,
    MinWidth = 400,
    MaxHeight = 800
};

When Width or Height is set, auto-sizing is disabled for that dimension.

Theming

Light/Dark Switching

public class SettingsViewModel
{
    private readonly IMessageBoxThemeService _theme;

    public SettingsViewModel(IMessageBoxThemeService theme) => _theme = theme;

    public void SetDarkMode(bool dark)
    {
        _theme.SetTheme(dark ? MessageBoxTheme.Dark : MessageBoxTheme.Light);
    }
}

Custom Title Bar Color

using System.Windows.Media;

var options = new MessageBoxOptions
{
    Title = "Custom Header",
    Message = "Title bar uses custom color.",
    TitleBarColor = Colors.DarkBlue
};

Title text color adjusts automatically for contrast.

Resource Overrides

Override colors by redefining keys after merging base resources:

<ResourceDictionary.MergedDictionaries>
    <ResourceDictionary Source="pack://application:,,,/FluentDialogs.Wpf;component/Themes/FluentLight.xaml"/>
</ResourceDictionary.MergedDictionaries>


<Color x:Key="PrimaryButtonBackgroundColor">#00A86B</Color>

Key color resources: DialogBackgroundColor, DialogForegroundColor, PrimaryButtonBackgroundColor, DangerButtonBackgroundColor, etc.

Common Scenarios

Error with Exception Details

try
{
    await SomeOperationAsync();
}
catch (Exception ex)
{
    await _messageBox.ErrorAsync("Operation failed.", ex);
}

Shows expandable stack trace.

License Agreement

var result = await _messageBox.LicenseAsync(
    title: "License Agreement",
    message: "Please read and accept:",
    detailedText: licenseText,
    requireScrollToBottom: true);

if (result.Result == MessageBoxResult.OK)
{
    // User accepted
}

Accept button is disabled until user scrolls to bottom.

Auto-Closing Dialog

var result = await _messageBox.TimeoutAsync(
    message: "Session expires in 10 seconds.",
    timeoutSeconds: 10,
    timeoutResult: MessageBoxResult.Cancel);

if (result.TimedOut)
{
    // Dialog auto-closed
}

DialogResult Properties

Extended dialogs return DialogResult with additional data:

DialogResult implicitly converts to MessageBoxResult.

Rules and Limitations

Intended For

• Modal confirmation dialogs
• User notifications (info, warning, error)
• Simple input collection
• License/disclaimer acceptance

Not Intended For

• Complex forms (use dedicated windows)
• Non-blocking notifications (use toast/snackbar)
• File/folder selection (use system dialogs)
• Long-running progress (use progress windows)

Constraints

• All methods are async; do not block with .Result or .Wait()
• Dialogs are always modal
• Cannot specify both Buttons and CustomButtons
• At most one IsDefault and one IsCancel button allowed
• Owner should be set for proper modal behavior when possible

Screenshots

Light Theme

Dark Theme

Dialog Examples

Info	Confirm	Error

Custom Buttons	Input	Selection

License

MIT