简单的代码如下：

public static string[] GetProductList(string inputstring)
        {
            char[] split = { ',', ' ', ';', '；', '，', ':', '：', (char)10, (char)13 };
            return inputstring.Split(split, StringSplitOptions.RemoveEmptyEntries);
        }

获取sql in 部分的代码：

public static string GetSQLInPartByProductlist(string[] productlist)
        {
            string inpartsql = " in  (";
            string endpart = ")";

foreach (string item in productlist)
            {
                inpartsql += "'" + item + "'," + " ";
            }
            inpartsql = inpartsql.Remove(inpartsql.Length - 2);
            inpartsql += endpart;
            return inpartsql;

}

测试的界面