need a regex for a positive max 2 digits after . floating number

Hi I need a C# regex fo开发者_运维问答r a positive floatin no with maximum 2 digits for decimals. Also the regex should check for letters and alphanumerical chars (not allow them) and not allow also the input value to be empty (0 characters). Thanks

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^[+]?[0-9]+([.][0-9]{1,2})?$

This will force it to have either a + or nothing at the start, followed by at least 1 number, then optional (decimal followed by 1 or 2 numbers)

For others, yes, I know of \d, :digit:, using \., etc. I just prefer using [0-9] and [.], it makes them stand out easier for me.