[已解决]An unhandled exception occurred while processing the request.

An unhandled exception occurred while processing the request.

InvalidOperationException: The layout view '~/Areas/Admin/Views/Shared/_Layout' could not be located. The following locations were searched:
~/Areas/Admin/Views/Shared/_Layout

Microsoft.AspNetCore.Mvc.Razor.RazorView.GetLayoutPage(ViewContext context, string executingFilePath, string layoutPath)

解决方法：

将模板页

@{
Layout = "~/Areas/Admin/Views/Shared/_Layout";
}

改成：

@{
Layout = "~/Areas/Admin/Views/Shared/_Layout.cshtml";
}