using System;

using System.Collections.Generic;

using System.Data;

using System.Linq;

using System.Reflection;

using System.Text;

using System.Text.RegularExpressions;

using System.Threading.Tasks;

namespace ConsoleApplication13

{

public static class ListAndTableExtension

{

public static DataTable ToDataTable<T>(this List<T> list) where T : new()

{

DataTable table = new DataTable();

PropertyInfo[] ps = typeof(T).GetProperties();

foreach (PropertyInfo p in ps)

{

if (!p.PropertyType.IsGenericType)

{

table.Columns.Add(p.Name, p.PropertyType);

}

else

{

Type GenericTypeDefinition= p.PropertyType.GetGenericTypeDefinition();

if (GenericTypeDefinition == typeof(Nullable<>))

{

table.Columns.Add(p.Name,Nullable.GetUnderlyingType(p.PropertyType));

}

}

}

foreach (T obj in list)

{

DataRow row = table.NewRow();

foreach (PropertyInfo p in ps)

{

row[p.Name] = p.GetValue(obj);

}

table.Rows.Add(row);

}

return table;

}

public static List<T> ToList<T>(this DataTable table) where T:new()

{

List<T> list = new List<T>();

PropertyInfo[] ps = typeof(T).GetProperties();

foreach (DataRow row in table.Rows)

{

T obj = new T();

foreach (DataColumn col in table.Columns)

{

foreach (PropertyInfo p in ps)

{

if (p.Name == col.ColumnName)

{

if (!p.PropertyType.IsGenericType)

{

p.SetValue(obj, string.IsNullOrEmpty(row[p.Name].ToString()) ? null : Convert.ChangeType(row[p.Name].ToString(), p.PropertyType));

}

else

{

if(p.PropertyType.GetGenericTypeDefinition()==typeof(Nullable<>))

{

p.SetValue(obj,string.IsNullOrEmpty(row[p.Name].ToString())?null:Convert.ChangeType(row[p.Name],Nullable.GetUnderlyingType(p.PropertyType)));

}

}

}

}

}

list.Add(obj);

}

return list;

}

}

public class Student

{

public int? StuNo { get; set; }

public string Name { get; set; }

public string Sex { get; set; }

public int Age { get; set; }

public override string ToString()

{

return this.StuNo + ":" + this.Name + ":" + this.Sex + ":" + this.Age;

}

}

class Program

{

public static List<Student> StuList = new List<Student>();

static void Main(string[] args)

{

StuList.Add(new Student() { StuNo = 1, Name = "1", Sex = "1", Age = 1 });

StuList.Add(new Student() { StuNo = 2, Name = "2", Sex = "2", Age = 2 });

StuList.Add(new Student() { StuNo = 3, Name = "3", Sex = "3", Age = 3 });

StuList.Add(new Student() { StuNo = 4, Name = "4", Sex = "4", Age = 4 });

StuList.Add(new Student() { StuNo = 5, Name = "5", Sex = "5", Age = 5 });

DataTable table = StuList.ToDataTable<Student>();

List<Student> stus = table.ToList<Student>();

DataTable dt2 = table.Clone();

Console.WriteLine(" dt.ToList<Student>()输出学生列表");

stus.ForEach(a => { Console.WriteLine(a.ToString()); });

foreach (DataRow odr in table.Rows)

{

DataRow ndr = dt2.NewRow();

ndr.ItemArray = odr.ItemArray;

dt2.ImportRow(odr);

}

string s = "ABC_EDF_CCS";

List<string> strList=s.Split('_').ToList();

StringBuilder sb = new StringBuilder();

foreach (string s2 in strList)

{

sb.Append(ReplaceString(s2));

}

Console.WriteLine("格式化前字符串："+s+"格式化后字符串："+sb.ToString());

Console.Read();

}

public static string ReplaceString(string s)

{

return Regex.Replace(s, @"([A-Za-z]{1})([A-Za-z]*)",MathcEval);

}

private static string MathcEval(Match match)

{

return match.Groups[1].Value.ToUpper() + match.Groups[2].Value.ToLower();

}

}

}