如何限制特定搜索的通配符

Question

我想验证输入字符串。规则如下：

1) %somestring 2）一些字符串％ 3)%somestring%

如果输入的字符串符合上述格式，则为真，否则为假。

注意：somestring 不应该有 %

Answer 1

尝试遵循正则表达式。希望我正确地解释了作业。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] inputs = {
               "Where Name like '%A%'",
               "Where Name like '%A'",
               "Where Name like 'A%'",
               "Where Name like '%A%B%C'",
               "Where Name Like %%",
               "Where Name Like %"
                              };

            string pattern = @"Where\s+[A-Za-z]+\s+like\s+(?'wildcard'.*)";

            foreach (string input in inputs)
            {
                Boolean valid = false;

                Match match = Regex.Match(input, pattern);
                if (match.Success)
                {
                    string wildcard = match.Groups["wildcard"].Value;
                    int percentCount = wildcard.Where(x => x == '%').Count();
                    if ((percentCount == 1) || (percentCount == 2))
                    {
                        string wildcardPattern = "^('%A%'|'%A'|'A%')$";
                        Match match2 = Regex.Match(wildcard, wildcardPattern);
                        if (match2.Success) valid = true;
                    }
                }
                Console.WriteLine("Success = '{0}', string = '{1}'", valid ? "true" : "false", input);
            }
            Console.ReadLine();
        }
    }
}