I’m making some code to extract the 64x64px variant of the icon in an exe file.
The following code does work, but it outputs a grayscale 16x16px image.
I’m still a bit new to rust so please excuse the bad code.
I’m using winapi version 0.3.9 with the features: “winuser”, “shellapi”.

use std::ffi::CString;
use std::ptr;
use iced::widget::image::Handle;
use winapi::shared::minwindef::DWORD;
use winapi::um::shellapi::ExtractIconA;
use winapi::shared::windef::HICON;
use winapi::um::wingdi::{CreateDIBSection, DeleteObject, GetDIBits, BITMAPINFO, BITMAPINFOHEADER, BI_RGB, DIB_RGB_COLORS, RGBQUAD};
use winapi::um::winuser::{DestroyIcon, GetIconInfo};
use winapi::um::wingdi::{CreateCompatibleDC, SelectObject};

pub fn exe_icon_to_vec_u8(path: &str) -> Result<Handle, String> {
    let c_path = CString::new(path).map_err(|_| "Invalid path".to_string())?;
    let hicon: HICON = unsafe { ExtractIconA(ptr::null_mut(), c_path.as_ptr(), 0) };
    if hicon.is_null() {
        return Err("Failed to extract icon".into());
    }
    let mut icon_info = unsafe { std::mem::zeroed() };
    if unsafe { GetIconInfo(hicon, &mut icon_info) } == 0 {
        unsafe { DestroyIcon(hicon) };
        return Err("Failed to get icon info".into());
    }
    let mut bmp_info = BITMAPINFO {
        bmiHeader: BITMAPINFOHEADER {
            biSize: std::mem::size_of::<BITMAPINFOHEADER>() as DWORD,
            biWidth: 64, biHeight: -64, biPlanes: 1, biBitCount: 32,
            biCompression: BI_RGB, biSizeImage: 0, biXPelsPerMeter: 0,
            biYPelsPerMeter: 0, biClrUsed: 0, biClrImportant: 0,
        }, bmiColors: [RGBQUAD { rgbBlue: 0, rgbGreen: 0, rgbRed: 0, rgbReserved: 0 }; 1],
    };
    let mut pixels: Vec<u8> = vec![0; 64 * 64 * 4];
    let hdc = unsafe { CreateCompatibleDC(ptr::null_mut()) };
    if hdc.is_null() {
        unsafe {
            DestroyIcon(hicon);
        }
        return Err("Failed to create compatible DC".into());
    }
    let hbitmap = unsafe {
        CreateDIBSection(
            hdc,
            &mut bmp_info,
            DIB_RGB_COLORS,
            &mut pixels.as_mut_ptr() as *mut _ as *mut _,
            ptr::null_mut(),
            0,
        )
    };
    if hbitmap.is_null() {
        unsafe {
            DeleteObject(icon_info.hbmColor as _);
            DeleteObject(icon_info.hbmMask as _);
            DestroyIcon(hicon);
        }
        return Err("Failed to create DIB section".into());
    }
    unsafe {
        SelectObject(hdc, hbitmap as _);
        GetDIBits(
            hdc,
            icon_info.hbmColor,
            0,
            64,
            pixels.as_mut_ptr() as *mut _,
            &mut bmp_info,
            DIB_RGB_COLORS,
        );
        DeleteObject(hbitmap as _);
        DeleteObject(icon_info.hbmColor as _);
        DeleteObject(icon_info.hbmMask as _);
        DestroyIcon(hicon);
    }
    Ok(Handle::from_pixels(64, 64, pixels))
}

I tried to find some cargo packages that do this but with no success.