简化替换为正则表达式

Question

如何用正则表达式替换这个相当笨拙的代码？

Dim InvoiceNumber As String = filename.Split("_")(1).Replace("-00", "/").Replace("-0", "/0").Replace("-", "/")

要处理的文件名示例：

617809_53070664_EB867_20170710
617809_53069537_308CB588_20170710
617809_53069392_307RS0635_20170710
617809_53060543-001_307RS0630_20170710

我需要得到：

53070664
53069537
53069392
53060543/1

Answer 1

您可以尝试这种方法（run the sample）

  string pattern = @"\d+_(\d+)(?:-0{0,}(\d+))?_.*";
        string input = @"617809_53070664_EB867_20170710
617809_53069537_308CB588_20170710
617809_53069392_307RS0635_20170710
617809_53060543-001_307RS0630_20170710
";

            foreach (Match m in Regex.Matches(input, pattern))
            {
                if(m.Groups[2].Value!="")
                 Console.WriteLine(m.Groups[1]+"/"+m.Groups[2]);
                else
                 Console.WriteLine(m.Groups[1]);
            }
        }