HermesWindow

The main class for creating native windows with WebView.

Constructor

public HermesWindow()

Creates a new Hermes window for the current platform.

Static Methods

Prewarm

public static void Prewarm()

Pre-warm platform resources for faster first-window creation. Call this early in application startup.

On Windows, this begins WebView2 environment creation on a background thread. On Linux and macOS, this is a no-op.

Configuration Methods

These methods use a fluent API and must be called before Show() or WaitForClose().

SetTitle

public HermesWindow SetTitle(string title)

Set the window title.

SetSize

public HermesWindow SetSize(int width, int height)

Set the initial window size in pixels.

SetPosition

public HermesWindow SetPosition(int x, int y)

Set the initial window position.

Center

public HermesWindow Center()

Center the window on screen when shown.

SetResizable

public HermesWindow SetResizable(bool resizable)

Set whether the window can be resized.

SetMinSize / SetMaxSize

public HermesWindow SetMinSize(int width, int height)
public HermesWindow SetMaxSize(int width, int height)

Set size constraints.

SetDevToolsEnabled

public HermesWindow SetDevToolsEnabled(bool enabled)

Enable or disable developer tools (F12).

SetCustomTitleBar

public HermesWindow SetCustomTitleBar(bool enabled)

Enable custom title bar mode:

• macOS: Transparent title bar with native traffic light buttons
• Windows/Linux: Chromeless mode for fully custom window chrome

RememberWindowState

public HermesWindow RememberWindowState(string? key = null)

Enable window state persistence. Position, size, and maximized state will be saved on close and restored on next launch.

Content Methods

Load

public HermesWindow Load(string url)

Load a URL in the WebView.

LoadHtml

public HermesWindow LoadHtml(string html)

Load HTML content directly.

RegisterCustomScheme

public HermesWindow RegisterCustomScheme(
    string scheme,
    Func<string, (Stream? Content, string? ContentType)> handler)

Register a custom URL scheme handler for loading bundled assets.

Event Methods

OnClosing

public HermesWindow OnClosing(Action handler)

Register a handler for when the window is closing.

OnResized

public HermesWindow OnResized(Action<int, int> handler)

Register a handler for when the window is resized.

OnWebMessage

public HermesWindow OnWebMessage(Action<string> handler)

Register a handler for messages from JavaScript.

Lifecycle Methods

Show

public void Show()

Show the window and return immediately.

WaitForClose

public void WaitForClose()

Show the window and block until it is closed.

Close

public void Close()

Close the window programmatically.

Properties

MenuBar

public NativeMenuBar MenuBar { get; }

Access the native menu bar for this window.

Dialogs

public IDialogBackend Dialogs { get; }

Access native dialogs (file open/save).

Title

public string Title { get; set; }

Get or set the window title (works after initialization).

Size

public (int Width, int Height) Size { get; set; }

Get or set the window size.

Position

public (int X, int Y) Position { get; set; }

Get or set the window position.

IsMaximized

public bool IsMaximized { get; }

Whether the window is currently maximized.

Runtime Methods

SendMessage

public void SendMessage(string message)

Send a message to JavaScript in the WebView.

Invoke

public void Invoke(Action action)

Execute an action on the UI thread.

MaximizeWindow / MinimizeWindow / RestoreWindow

public void MaximizeWindow()
public void MinimizeWindow()
public void RestoreWindow()

Control window state at runtime.

ToggleMaximize

public void ToggleMaximize()

Toggle between maximized and normal state.

Example

using Hermes;

HermesWindow.Prewarm();

var window = new HermesWindow()
    .SetTitle("My App")
    .SetSize(1024, 768)
    .Center()
    .SetDevToolsEnabled(true)
    .RememberWindowState()
    .OnClosing(() => Console.WriteLine("Closing..."))
    .LoadHtml("<h1>Hello!</h1>");

window.WaitForClose();