c#——list中元素转化（ConvertAll select foreach）

ConvertAll 将当前 List 中的元素转换为另一种类型，并返回包含转换后的元素的列表

List<string> ls = new List<string>() { "1", "2", "3" };
List<int> li = ls.ConvertAll<int>(i=>int.Parse(i));
var li = ls.Select(i=>int.Parse(i));

string fields =
  "First Name,Middle Name,Last Name,Birth Date,Gender,Address,City,State,Zip,Email";
List<string> fieldList = new List<string>(fields.Split(','));
fieldList.ConvertAll<string>(new Converter<string, string>(
    delegate(string str)
    {
        str = str.Trim();
        str = str.Replace(' ', '_');
        return str;
    }
));

string str = String.Join(",", intList.ConvertAll<string>(new Converter<int, string>(m => m.ToString())).ToArray());

用 ConvertAll 一句代码将 List<int> 用逗号连接为字符串

ForEach

List<string> ls = new List<string> { "wxd", "lzm" };
ls.ForEach(v=> Console.WriteLine(v));