Siticone Wallpaper Panel

The SiticoneWallpaperPanel is a specialized container control designed for high-fidelity background image rendering. Unlike the standard Panel, it offers built-in opacity control for images (without affecting child controls), responsive scaling modes, and optimized double-buffering to prevent flicker during resizing.

Key Features

Designed to solve common WinForms background image limitations.

Feature	Description
`Image Opacity`	Allows fading the background image (0.0 to 1.0) to blend it with the panel's `BackColor`, creating subtle textures or watermarks.
`Responsive Scaling`	Includes a 'Zoom' mode that preserves aspect ratio while filling the panel, preventing image distortion common in standard controls.
`Flicker-Free`	Uses `OptimizedDoubleBuffer` and `AllPaintingInWmPaint` styles to ensure smooth resizing animations.

Properties

Configuration options for image handling and display.

Property	Type	Description & Usage Example
`Wallpaper`	Image	panel.Wallpaper = Resources.Background; The main image to display. Replaces the standard `BackgroundImage` property.
`WallpaperOpacity`	float	panel.WallpaperOpacity = 0.5f; Controls transparency of the image only. `1.0` = Fully Opaque (Normal) `0.5` = Semi-transparent (Blends with BackColor) `0.0` = Invisible
`WallpaperStretchMode`	Enum	panel.WallpaperStretchMode = WallpaperStretchMode.Zoom; Determines how the image is sized. See the Enumerations section below.
`BackColor`	Color	panel.BackColor = Color.Black; The solid color drawn behind the wallpaper. Essential when `WallpaperOpacity` is less than 1.0 to control the blend tint.

Enumerations

WallpaperStretchMode Enum

public enum WallpaperStretchMode
{
                // Draws image at original size (0,0). Clips if too large.
    None,

                // Stretches image to fill panel. Distorts aspect ratio.
    Stretch,

                // Scales image to fit panel while keeping aspect ratio. 
                // Centers image automatically. Best for responsive UIs.
    Zoom,

                // Centers image at original size. Clips edges if too large.
    Center
}

Detailed Usage Examples

Example 1: Subtle Watermark Background

Creates a professional-looking container with a faint logo in the background. Using a low opacity blends the image with the panel's white background.

C# - Watermark Setup

private void InitializeWatermarkPanel()
{
                var pnl = new SiticoneWallpaperPanel();
    pnl.Dock = DockStyle.Fill;
    pnl.BackColor = Color.White;
    
                // Set the logo image
    pnl.Wallpaper = Properties.Resources.CompanyLogo;
    
                // Make it faint (15% visibility)
    pnl.WallpaperOpacity = 0.15f;
    
                // Ensure logo stays proportional and centered
    pnl.WallpaperStretchMode = WallpaperStretchMode.Zoom;
    
                this.Controls.Add(pnl);
}

Example 2: Darkened Hero Image

Often used in login screens. Sets a black background and reduces image opacity to make white text readable on top of a busy photo.

C# - Hero Section

private void SetupLoginBackground()
{
    heroPanel.BackColor = Color.Black; // Dark base
    heroPanel.Wallpaper = Image.FromFile("cityscape.jpg");
    
                // Darken image by showing 60% image, 40% black background
    heroPanel.WallpaperOpacity = 0.6f; 
    
                // Fill the entire space, potentially cropping edges to maintain ratio
                // Note: Zoom fits *inside*. To fill *outside* (Crop), use logic or custom paint.
                // Here we use Stretch for full coverage if ratio is close.
    heroPanel.WallpaperStretchMode = WallpaperStretchMode.Stretch;
}

Example 3: Interactive Opacity Slider

Dynamically changing opacity at runtime based on user input (e.g., a slider control).

C# - Dynamic Opacity

private void trackBarOpacity_Scroll(object sender, EventArgs e)
{
                // Convert slider value (0-100) to float (0.0-1.0)
                float opacity = trackBarOpacity.Value / 100f;
    
                // Update panel immediately (triggers repaint)
    siticoneWallpaperPanel1.WallpaperOpacity = opacity;
    
    lblOpacityValue.Text = $"Opacity: {opacity:P0}";
}