Crate alt_icons 

A Windows executable that permanently changes its own icon.

The model is borrowed from iOS alternate icons: a closed set of icons, declared at build time, switched by name at runtime. What is not borrowed is where the icon lives. On iOS and Android the thing that changes is the launcher entry; here it is the executable file itself, so the new icon is what Explorer shows for the .exe, and it survives a reboot.

alt_icons::include_icons!();

fn main() -> Result<(), alt_icons::Error> {
    alt_icons::init()?;
    alt_icons::set_icon(AppIcon::Dark)?;
    Ok(())
}

Declare the icon set in build.rs with alt_icons::build::configure. The build feature enables this helper when alt-icons is used as a build-dependency. A build script runs before macro expansion, so it cannot read a list declared by a macro, and the default icon has to be baked at build time or the binary you ship has no icon at all.

What this costs

Every swap rewrites the executable, so its hash changes. Heuristic antivirus and SmartScreen reputation both notice a binary that rewrites itself. The default icon is baked at build time precisely so this only ever happens when your user asks for a different icon, never on first launch of a fresh download.

Signing is incompatible: rewriting the PE invalidates an Authenticode signature.

Macros

include_icons

Pulls in the generated AppIcon enum. Call once, at the root of your crate.

Structs

Options

Runtime behavior, configured once near the start of the application.

Enums

Error

Everything that can go wrong during a swap.

Traits

Icon

One icon in the set. Implemented by the AppIcon enum that build::configure generates; there is no reason to implement it by hand.

Functions

current_icon

init

No-op away from Windows, so a cross-platform crate still builds.

init_with_options

No-op away from Windows, just like init.

set_icon