MatchEvaluator Delegato

Definizione

Rappresenta il metodo chiamato ogni volta che si individua una corrispondenza di un'espressione regolare durante un'operazione del metodo Replace.Represents the method that is called each time a regular expression match is found during a Replace method operation.

public delegate System::String ^ MatchEvaluator(Match ^ match);
[System.Serializable]
public delegate string MatchEvaluator(Match match);
type MatchEvaluator = delegate of Match -> string
Public Delegate Function MatchEvaluator(match As Match) As String 

Parametri

match
Match

Oggetto Match che rappresenta una corrispondenza di un'espressione regolare singola durante un'operazione del metodo Replace.The Match object that represents a single regular expression match during a Replace method operation.

Valore restituito

String

Stringa restituita dal metodo rappresentato dal delegato MatchEvaluator.A string returned by the method that is represented by the MatchEvaluator delegate.

Ereditarietà
MatchEvaluator
Attributi

Esempi

Nell'esempio di codice seguente viene MatchEvaluator usato il delegato per sostituire ogni gruppo di caratteri corrispondente con il numero di occorrenze della corrispondenza.The following code example uses the MatchEvaluator delegate to replace every matched group of characters with the number of the match occurrence.

#using <System.dll>

using namespace System;
using namespace System::Text::RegularExpressions;
ref class MyClass
{
public:
   static int i = 0;
   static String^ ReplaceCC( Match^ m )
   {
      
      // Replace each Regex cc match with the number of the occurrence.
      i++;
      return i.ToString();
   }

};

int main()
{
   String^ sInput;
   String^ sRegex;
   
   // The string to search.
   sInput = "aabbccddeeffcccgghhcccciijjcccckkcc";
   
   // A very simple regular expression.
   sRegex = "cc";
   Regex^ r = gcnew Regex( sRegex );
   
   // Assign the replace method to the MatchEvaluator delegate.
   MatchEvaluator^ myEvaluator = gcnew MatchEvaluator( &MyClass::ReplaceCC );
   
   // Write out the original string.
   Console::WriteLine( sInput );
   
   // Replace matched characters using the delegate method.
   sInput = r->Replace( sInput, myEvaluator );
   
   // Write out the modified string.
   Console::WriteLine( sInput );
}
// The example displays the following output:
//       aabbccddeeffcccgghhcccciijjcccckkcc
//       aabb11ddeeff22cgghh3344iijj5566kk77
using System;
using System.Text.RegularExpressions;

class MyClass
{
   static void Main(string[] args)
   {
      string sInput, sRegex;

      // The string to search.
      sInput = "aabbccddeeffcccgghhcccciijjcccckkcc";

      // A very simple regular expression.
      sRegex = "cc";

      Regex r = new Regex(sRegex);
        
      MyClass c = new MyClass();

      // Assign the replace method to the MatchEvaluator delegate.
      MatchEvaluator myEvaluator = new MatchEvaluator(c.ReplaceCC);
        
      // Write out the original string.
      Console.WriteLine(sInput);

      // Replace matched characters using the delegate method.
      sInput = r.Replace(sInput, myEvaluator);
      
      // Write out the modified string.
      Console.WriteLine(sInput);
   }

   public string ReplaceCC(Match m)
   // Replace each Regex cc match with the number of the occurrence.
   {
      i++;
      return i.ToString() + i.ToString();		
   }
   public static int i=0;
}
// The example displays the following output:
//       aabbccddeeffcccgghhcccciijjcccckkcc
//       aabb11ddeeff22cgghh3344iijj5566kk77
Imports System.Text.RegularExpressions

Module Module1
   Public Sub Main()
      Dim sInput, sRegex As String

      ' The string to search.
      sInput = "aabbccddeeffcccgghhcccciijjcccckkcc"

      ' A very simple regular expression.
      sRegex = "cc"

      Dim r As Regex = New Regex(sRegex)

      ' Assign the replace method to the MatchEvaluator delegate.
      Dim myEvaluator As MatchEvaluator = New MatchEvaluator(AddressOf ReplaceCC)

      ' Write out the original string.
      Console.WriteLine(sInput)
      ' Replace matched characters using the delegate method.
      sInput = r.Replace(sInput, myEvaluator)
      ' Write out the modified string.
      Console.WriteLine(sInput)
   End Sub

   Public Function ReplaceCC(ByVal m As Match) As String
      ' Replace each Regex match with the number of the match occurrence.
      static i as integer
   
      i = i + 1
      Return i.ToString() & i.ToString()
   End Function
End Module
' The example displays the following output:
'       aabbccddeeffcccgghhcccciijjcccckkcc
'       aabb11ddeeff22cgghh3344iijj5566kk77

Commenti

È possibile usare un MatchEvaluator metodo delegato per eseguire un'operazione di verifica o manipolazione personalizzata per ogni corrispondenza trovata da un metodo di sostituzione Regex.Replace(String, MatchEvaluator), ad esempio.You can use a MatchEvaluator delegate method to perform a custom verification or manipulation operation for each match found by a replacement method such as Regex.Replace(String, MatchEvaluator). Per ogni stringa corrispondente, il Replace metodo chiama il MatchEvaluator metodo Delegate con un Match oggetto che rappresenta la corrispondenza.For each matched string, the Replace method calls the MatchEvaluator delegate method with a Match object that represents the match. Il metodo Delegate esegue qualsiasi elaborazione preferita e restituisce una stringa che il Replace metodo sostituisce per la stringa corrispondente.The delegate method performs whatever processing you prefer and returns a string that the Replace method substitutes for the matched string.

Metodi di estensione

GetMethodInfo(Delegate)

Ottiene un oggetto che rappresenta il metodo rappresentato dal delegato specificato.Gets an object that represents the method represented by the specified delegate.

Si applica a

Vedi anche