替换字符串中的单个字符实例，保持多个字符不变

Question

如何将periods替换为spaces，但保留...？

string test = "This.is.a.test...";

test = test.Replace(".", " ");

http://rextester.com/DLEHI1253

Answer 1

您可以使用此(?<!\.)\.(?!\.)

var regex = new Regex(@"(?<!\.)\.(?!\.)");
var ressult = regex.Replace("This.is.a.test..."," ");
Console.WriteLine(ressult);

输出

This is a test...

Demo here