Cross-Platform C# UIWrite Once, Run Everywhere
CrossSharp is a modern C# UI library that lets you build native applications for Windows, Linux, macOS, Android, and iOS using a single codebase. Powered by SDL3 for high-performance rendering.
Why CrossSharp?
A unified API for building desktop applications that look and feel native on every platform.
Write Once, Run Everywhere
Build your application with a single C# codebase. CrossSharp handles all platform differences behind the scenes - you just focus on your app.
SDL3-Powered Rendering
High-performance graphics rendering using SDL3 (Simple DirectMedia Layer) with hardware acceleration support across all platforms.
Powerful Theme System
8 built-in themes including Light, Dark, High Contrast, and custom LimitlessSoft themes. Full control over colors, spacing, and corner radius.
Rich Control Library
17+ ready-to-use controls: Forms, Layouts (Stacked, Flow, Tabbed), Buttons, Inputs, DataGrids, Charts, Dropdowns, Accordions, and more.
Modern .NET 10
Built on the latest .NET 10 framework with C# 12+ features, nullable reference types, and implicit usings for a modern development experience.
Unified Notifications
A single API for notifications across all platforms. Write notification code once and it works on Windows, Linux, macOS, Android, and iOS.
UI Controls
A comprehensive library of ready-to-use controls for building professional desktop applications.
Form
Main window container
ModularForm
Multi-page forms
StaticLayout
Absolute positioning
StackedLayout
Vertical/horizontal stacking
FlowLayout
Responsive wrapping
TabbedLayout
Tabbed navigation
Panel
Container control
Label
Text display
Button
Clickable with images
Input
Text input field
FilesPicker
Native file dialogs
Dropdown
Selection control
Accordion
Expandable sections
Chart
Data visualization
DataGrid
Tabular data display
ImagePreview
Image display
ThemePicker
Theme selection
How It Works
Write your code once in C#. CrossSharp takes care of making it work seamlessly on Windows, Linux, macOS, Android, and iOS.
One Codebase
Write your application logic, UI, and styling in a single C# project. No platform-specific code needed.
Native Performance
CrossSharp uses SDL3 for hardware-accelerated rendering, giving you native-level performance on every platform.
One Build, All Platforms
A single build command produces all files for Windows, Linux, macOS, Android, and iOS. Ship directly to any platform.
public class MainForm : Form
{
public MainForm()
{
Title = "Hello CrossSharp";
Width = 800;
Height = 600;
var button = new Button
{
Text = "Click Me!",
Width = 120,
Height = 40
};
button.Click += (s, e) =>
Console.WriteLine("Clicked!");
Controls.Add(button);
}
}dotnet build -c ReleaseOne command generates everything you need
MyApp.exeMyAppMyApp.appMyApp.apkMyApp.ipaEach output is ready to ship — no additional configuration required
Getting Started
Get up and running with CrossSharp in just a few steps.
Install the Package
Add CrossSharp to your .NET project via NuGet.
dotnet add package CrossSharpCreate Your Application
Set up the application builder with your configuration.
var config = new BaseConfiguration()
{
ApplicationName = "MyApp"
};
var builder = new ApplicationBuilder(config);Run Your Form
Create a form class and run your application.
builder.Run<MainForm>();Built-in Themes
CrossSharp comes with 8 professionally designed themes out of the box. Switch themes at runtime or create your own custom themes.
// Apply a theme
form.Theme = new LightTheme();
// Or create your own
public class MyTheme : ThemeBase
{
public MyTheme()
{
PrimaryColor = new ColorRgba(14, 165, 233);
LayoutBackgroundColor = new ColorRgba(26, 39, 68);
DefaultCornerRadius = 8;
}
}