c# - Special letters check -

how can check if textbox contains numbers, letters, , have special letters "õ, ä, ö, ü"?

i use code check numbers , letters:

regex.ismatch(value, "^[a-z0-9]+$", regexoptions.ignorecase) 

does how can strip non-ascii characters string? (in c#) contain pointers?

you include unicode using \uxxxx syntax within regex additional letters want strip test for.

regex.ismatch(value, "^[a-z0-9\u00c0-\u00f6]+$", regexoptions.ignorecase)