C＃替換部分消息

Question

string message = "Your purchase of $ 100.00 is awaiting for confirmation. Please use PIN 8967 to complete the transaction. Reference Number :1237689"; 

string output = Regex.Replace(message, @"[\d-]", "*"); 

Console.WriteLine("Message : " + message); 

Console.WriteLine("Output : " + output); 

Console.ReadLine(); 

我想只替換消息的PIN。但上面的消息從*字符替換所有數值。

Answer 1

string message = "Your purchase of $ 100.00 is awaiting for confirmation. Please use PIN 8967 to complete the transaction. Reference Number :1237689"; 
string output = Regex.Replace(message, @"(?<=PIN\s*\d*)\d", "*"); 

或

string message = "Your purchase of $ 100.00 is awaiting for confirmation. Please use PIN 8967 to complete the transaction. Reference Number :1237689"; 
string output = Regex.Replace(message, @"(?<=PIN\s*)\d+", m => new string('*', m.Length));