It will stay running in the tray after you close the UWP main window.
在关闭UWP的主窗口后，托盘图标将继续运行，常驻于托盘。
By declaring the runFullTrust capability in Package.appxmanifest, we can launch a bundled non-UWP executable when launching the app. We rely on that non-UWP exe to show the tray icon and its context menu. They use AppService to communicate with each other.
We also declared a command line alias for this UWP, so we can use command line to launch the UWP part in the non-UWP part after the UWP is closed.
通过在Package.appxmanifest里声明runFullTrust能力，我们可以在应用启动的同时启动一个非UWP的可执行文件；我们依赖它显示托盘图标和上下文菜单。二者通过AppService交流。
我们同时为应用声明了一个命令行别名，以便于我们在UWP关闭后唤起它。