new[] {",", "/"}.Any(input.Contains)
or you can use Regex
Regex.IsMatch(input, @"[,/]");
Related posts:
How to set Tooltip for a particular Devexpress Gridview Column
Using Code Blocks, Mixing Text & C# Code and Comments in Asp.NET MVC Razor
Confirm before process with ASPxButton in Devexpress
How to get the integrity value for a jquery version of script reference in a web page
How to add placeholder to Multiple Selection DropDownList in Asp.Net MVC