Unity Setting for transparent background in StandAlone Windows

Assets\Editor\TransparentWindowSetting.cs

// origin : Transparent Unity App! : Code Monkey : https://www.youtube.com/watch?v=RqgsGaMPZTw

using UnityEngine;
using UnityEditor.Build;
using UnityEditor.Build.Reporting;

public class TransparentWindowSetting : IPreprocessBuildWithReport
{
	public int callbackOrder => 0;

	public void OnPreprocessBuild(BuildReport report)
	{
#if UNITY_STANDALONE_WIN
		UnityEditor.PlayerSettings.fullScreenMode = FullScreenMode.FullScreenWindow;
		UnityEditor.PlayerSettings.useFlipModelSwapchain = false;
		UnityEditor.PlayerSettings.runInBackground = true;
#endif
	}
}

Assets\Script\TransparentWindow.cs

// origin : Transparent Unity App! : Code Monkey : https://www.youtube.com/watch?v=RqgsGaMPZTw

using System;
using System.Runtime.InteropServices;

using UnityEngine;

public static class TransparentWindow
{
#if UNITY_STANDALONE_WIN
	private struct MARGINS
	{
		public int cxLeftWidth;
		public int cxRightWidth;
		public int cyTopHeight;
		public int cyBottomHeight;
	}

	[DllImport("user32.dll")]
	private static extern IntPtr GetActiveWindow();

	[DllImport("user32.dll")]
	private static extern int SetWindowLong(IntPtr hWnd,int nIndex,uint dwNewLong);

	[DllImport("user32.dll", EntryPoint = "GetSystemMetrics")]
	private static extern int GetSystemMetrics(int nIndex);

	[DllImport("user32.dll",EntryPoint = "SetLayeredWindowAttributes")]
	static extern int SetLayeredWindowAttributes(IntPtr hwnd,int crKey,byte bAlpha,int dwFlags);

	[DllImport("user32.dll",EntryPoint = "SetWindowPos")]
	private static extern int SetWindowPos(IntPtr hwnd,int hwndInsertAfter,int x,int y,int cx,int cy,int uFlags);

	[DllImport("Dwmapi.dll")]
	private static extern uint DwmExtendFrameIntoClientArea(IntPtr hWnd,ref MARGINS margins);

	const int GWL_STYLE = -16;
	const int GWL_EXSTYLE = -20;
	const uint WS_POPUP = 0x80000000;
	const uint WS_VISIBLE = 0x10000000;
	const uint WS_EX_LAYERED = 0x00080000;
	const int HWND_TOPMOST = -1;

	[RuntimeInitializeOnLoadMethod]
	public static void Init()
	{
		Camera.main.clearFlags = CameraClearFlags.SolidColor;
		Camera.main.backgroundColor = new Color(0,0,0,0);

#if !UNITY_EDITOR // You really don't want to enable this in the editor..
		SetWindowTransparent();
#endif
	}

	static void SetWindowTransparent()
	{
		int fWidth = Screen.width;
		int fHeight = Screen.height;
		var hwnd = GetActiveWindow();

		// Transparent windows with click through
		var margins = new MARGINS() { cxLeftWidth = -1 };
		DwmExtendFrameIntoClientArea(hwnd, ref margins);
		SetWindowLong(hwnd,GWL_EXSTYLE,WS_EX_LAYERED);
		SetLayeredWindowAttributes(hwnd, 0, 0, 1);
		SetWindowPos(hwnd,HWND_TOPMOST,0,0,0,0,0);
	}
#endif
}