Decorations Feature

The Decorations feature controls the visual appearance of the window: title, icon, chromeless mode, transparency, and background color. It is available at build time for initial configuration and at runtime for live changes.

Contents

• Builder Configuration
• Runtime Control
• Title and Icon
• Chromeless Mode
• Transparency
• Background Color

Builder Configuration

var builder = InfiniFrameWindowBuilder.Create()
    .SetTitle("My Application")
    .SetIconFile("assets/icon.ico")  // Windows and Linux only
    .SetWindowsAppUserModelId("MyCompany.MyApplication")
    .SetChromeless(true)
    .SetTransparent(true)
    .SetBackgroundColor("#FF5733")
    .SetStartPageUrl("https://myapp.local");

Method	Description
SetTitle(string)	Set the window title
SetIconFile(string)	Set the window icon (.ico on Windows, .png on Linux)
SetWindowsAppUserModelId(string)	Set the Windows taskbar identity
SetChromeless(bool)	Remove the native title bar and borders
SetTransparent(bool)	Enable window transparency
SetBackgroundColor(string?)	Set the native background color

Runtime Control

After Build(), change decorations through extension methods or the feature interface:

// Extension methods
window.SetTitle("New Title");
window.SetBackgroundColor("#00FF00");

// Direct feature access
window.Features.Decorations.SetTitle("New Title");
window.Features.Decorations.SetBackgroundColor("#00FF00");

// Read current values
string? title = window.Features.Decorations.Title;
string? color = window.Features.Decorations.BackgroundColor;
bool chromeless = window.Features.Decorations.IsChromeless;
bool transparent = window.Features.Decorations.IsTransparent;

Title and Icon

Builder-time

builder
    .SetTitle("My Application")
    .SetIconFile("assets/icon.ico")  // Windows and Linux only; .ico on Windows, .png on Linux
    .SetWindowsAppUserModelId("MyCompany.MyApplication") // Windows taskbar identity

SetWindowsAppUserModelId assigns an explicit process identity before the first window is shown. Use one stable, whitespace-free ID of at most 128 characters for every window in the process. For installed Windows applications, configure shortcuts with the same AppUserModelID so pinned taskbar items group with the running application.

Runtime

window.SetTitle("Updated Title");
string? currentTitle = window.Features.Decorations.Title;

window.Features.Decorations.SetIconFile("assets/new-icon.ico");

Platform notes

• Windows: .ico format recommended. The icon appears in the taskbar and title bar.
• Linux: .png format. Title length may be limited by the window manager (use SetLimitLinuxWindowTitleLength to manage this).
• macOS: Icon is not displayed in the title bar by default.

Chromeless Mode

Remove the native OS title bar so your web UI is the entire window:

builder
    .SetChromeless(true)
    .SetTransparent(true)  // Optional: for rounded corners or glassmorphism effects

On Windows, enabling chromeless mode automatically disables UseOsDefaultLocation, UseOsDefaultSize, and Resizable since they are incompatible. Set them explicitly if needed after calling SetChromeless.

See the Custom Window Chrome guide for Blazor components and JavaScript APIs for building your own title bar.

Transparency

Enable window transparency to let the web content show through:

builder
    .SetTransparent(true)
    .SetBackgroundColor("transparent")

Transparency is useful for:

• Acrylic or mica-style effects via CSS backdrop-filter
• Rounded corners on chromeless windows
• Fully transparent window regions

note

Transparency is a startup-only setting. It cannot be changed at runtime.

Background Color

Set the native window background color using hex color strings:

// Builder
builder
    .SetBackgroundColor("#FF5733")    // Set to a specific color
    .SetBackgroundColor("#AARRGGBB")  // With alpha channel
    .SetBackgroundColor("transparent") // Reset to platform default
    .SetBackgroundColor(null)          // Same as "transparent"

At runtime, the background color can be changed dynamically:

window.SetBackgroundColor("#00FF00");
window.Features.Decorations.SetBackgroundColor(null); // Reset
string? currentColor = window.Features.Decorations.BackgroundColor;

Platform	Builder-time	Runtime	Notes
Windows (WebView2)	Sets DefaultBackgroundColor at init; also applies if called before window creation	Sets DefaultBackgroundColor and reloads the webview	Color format: #RRGGBB or #AARRGGBB. Alpha=0 means transparent.
Linux (WebKitGTK)	Sets WebKitGTK background color at init	Sets WebKitGTK background color via webkit_web_view_set_background_color	Color format: #RRGGBB. GTK handles alpha via RGBA visual.
macOS (WKWebView)	Sets WKWebView backgroundColor at init	Sets WKWebView backgroundColor	Color format: #RRGGBB. NSColor parsing from hex string.

• Pass null or "transparent" to reset to the platform default (no background color override).
• Invalid hex strings throw ArgumentException at runtime.

See Also

• Custom Window Chrome Blazor components and JS API for chromeless windows
• Window Features Architecture How the feature system works
• Core Window Guide Builder API and feature overview