Regex-Anweisung nur für zahlen zwischen 0 und 255 in C#

^([0-9]{1,2}|1[0-9]{2}|2[0-4][0-9]|25[0-5])$

Dieses tool ist sehr hilfreich für solche Dinge. Ein wenig suchen, tut nicht weh, niemanden.

Wenn Sie zulassen möchten, dass führende Nullen das Muster muss angepasst werden, wenn. E. g.:

^([01][0-9][0-9]|2[0-4][0-9]|25[0-5])$

Versuchen, einen negativen Blick hinter:

(?<!\-)\b0*([0-9]{1,2}|1[0-9]{2}|2[0-4][0-9]|25[0-5])\b

Erklärung

<!--
(?<!\-)\b0*([0-9]{1,2}|1[0-9]{2}|2[0-4][0-9]|25[0-5])\b

Options: ^ and $ match at line breaks

Assert that it is impossible to match the regex below with the match ending at this position (negative lookbehind) «(?<!\-)»
   Match the character “-” literally «\-»
Assert position at a word boundary «\b»
Match the character “0” literally «0*»
   Between zero and unlimited times, as many times as possible, giving back as needed (greedy) «*»
Match the regular expression below and capture its match into backreference number 1 «([0-9]{1,2}|1[0-9]{2}|2[0-4][0-9]|25[0-5])»
   Match either the regular expression below (attempting the next alternative only if this one fails) «[0-9]{1,2}»
      Match a single character in the range between “0” and “9” «[0-9]{1,2}»
         Between one and 2 times, as many times as possible, giving back as needed (greedy) «{1,2}»
   Or match regular expression number 2 below (attempting the next alternative only if this one fails) «1[0-9]{2}»
      Match the character “1” literally «1»
      Match a single character in the range between “0” and “9” «[0-9]{2}»
         Exactly 2 times «{2}»
   Or match regular expression number 3 below (attempting the next alternative only if this one fails) «2[0-4][0-9]»
      Match the character “2” literally «2»
      Match a single character in the range between “0” and “4” «[0-4]»
      Match a single character in the range between “0” and “9” «[0-9]»
   Or match regular expression number 4 below (the entire group fails if this one fails to match) «25[0-5]»
      Match the characters “25” literally «25»
      Match a single character in the range between “0” and “5” «[0-5]»
Assert position at a word boundary «\b»
-->