C# 利用StringBuilder提升字符串拼接性能的小例子

string excelString = "";
foreach(var item in list){
        excelString += string.Format("<row>....{0}</row>",list.Title);
}

string excelString = new StringBuilder();
foreach(var item in list){
      excelString.AppendFormat("<row>......{0}</row>",list.Title);
}