LINQ小结

LINQ是自.net 3.5出现的新东东，个人认为它主要是对数据进行转换和对集合的查询

废话不多说了，直接看代码，代码里有相应的解释，在这里不作过多的说明

protected void Page_Load(object sender, EventArgs e)
{
    List<Student> students = new List<Student>();
    students.Add(new Student("11", "kingtiger"));
    students.Add(new Student("2", "wangbiao"));
    students.Add(new Student("3", "Mr Wang"));

    //var arr = students.Cast<Student>().OrderBy(r => r.ID.PadLeft(2, '0'));//按照ID进行排序
    //var arr = students.OfType<Student>().OrderBy(r => r.Name.Length);//排序应用，降序的话在前面加上-
    var arr = students.Cast<Student>().Where(r => r.ID == "01");//进行查询
    foreach (var l in arr)
    {
        Response.Write(l.ID + "#" + l.Name + "<br/>");
    }

    string[] strings = { "kingtiger", "wangbiao", null, "Mr wang" };
    //IEnumerable<string> ieStrings = strings.Cast<string>().Where(s => s.Length == 3);//该方法会报错，Cast会对所有选项进行转换，转换失败则抛出异常
    IEnumerable<string> ieStrings = strings.Cast<string>().Where(s => s.Length == 3);//该方法只转换能进行转换的选项，不能转换则跳出
    foreach (string s in ieStrings)
    {
        Response.Write(s + "<br/>");
    }
}