"''".Replace("''","/''")
            string a = "  a qa";
            string b = a.Replace(' ', '/');
String MM = "\"\"";
        String FF = MM.Replace("\"", "/\"");
用轉義字符 \
string str="''";
if(str.IndexOf("''")!=-1)
        {
            str.Replace("''","/''");
        }