[bug] Tauriv2 Windows 10 borderless window has a black line at the top

[xceyds]

Describe the bug

When using a borderless window on Windows 10 with Tauriv2, there's a black line appearing at the top of the window. This line seems to be part of the window's rendering, even though it should be completely borderless.

Reproduction

No response

Expected behavior

No response

Full tauri info output

✔ OS: Windows 10.0.22631 x86_64 (X64)
✔ WebView2: 128.0.2739.79
✔ MSVC: Visual Studio Community 2022
✔ rustc: 1.81.0 (eeb90cda1 2024-09-04)
✔ cargo: 1.81.0 (2dbb1af80 2024-08-20)
✔ rustup: 1.27.1 (54dd3d00f 2024-04-24)
✔ Rust toolchain: stable-x86_64-pc-windows-msvc (default)
✔ node: 20.17.0
✔ npm: 10.8.2

[-] Packages
    ✔ tauri 🦀: 2.0.0-rc.15
    ✔ tauri-build 🦀: 2.0.0-rc.12
    ✔ wry 🦀: 0.43.1
    ✔ tao 🦀: 0.30.1
    ✖ @tauri-apps/api: not installed!
    ✔ @tauri-apps/cli: 2.0.0-rc.16

[-] Plugins
    ✔ tauri-plugin-shell 🦀: 2.0.0-rc.3
    ✖ @tauri-apps/plugin-shell: not installed!

[-] App
    ✔ build-type: bundle
    ✖ CSP: unset
    ✔ frontendDist: ../src

Stack trace

No response

Additional context

No response

[yuzw1007]

我也遇到这个问题，还没找到解决办法。

[FabianLars]

This currently can only be "fixed" by disabling the window shadows ("shadows": false in the window config).

It's a pretty old issue, see https://github.com/rust-windowing/winit/blob/master/src/platform_impl/windows/event_loop.rs#L1087-L1097 for example (winit is tao's upstream, rust's main windowing library). I'd like to check if what they're talking about there is an issue for us too but i can't give you a time estimate nor can i promise that it'll work.

[yuzw1007]

这个黑线只有在窗口获取焦点时才有，失去焦点时窗口不存在这个条黑线。