身份证效验

 1 /// 作者：林宏权
 2 /// http://www.songzhuren.com/
 3 ///
 4 using System;
 5 using System.Collections.Generic;
 6 using System.Linq;
 7 using System.Text;
 8
 9 namespace IDCardCheck
10 {
11     class IDCard
12     {
13
14         //加权算法第一位到第十七位的系数：
15         int[] iW = new int[] { 7,9,10,5,8,4,2,1,6,3,7,9,10,5,8,4,2};
16
17         //身份证效验码字符串，与加权算法对位对应.
18         string Lastcode = "10X98765432";
19
20         /// <summary>
21         /// 获取身份证的第18位效验码.
22         /// </summary>
23         /// <param name="remainder"></param>
24         /// <returns>第18位效验码字字符串.</returns>
25         public string GetLastCode(int remainder)
26         {
27             //根据加权算法所获取的余数，返回对应的效验码.
28             return Lastcode[remainder].ToString();
29         }
30
31         /// <summary>
32         /// 通过加权算法，获取效验码的余数.
33         /// </summary>
34         /// <param name="IDCardNumber"></param>
35         /// <returns></returns>
36         public int GetTheRemainder(string IDCardNumber)
37         {
38             int theSum = 0;
39             //通过加权算法，求出身份证前17位的加权和.
40             for (int position = 0; position < 17;position++ )
41             {
42                 theSum += int.Parse(IDCardNumber[position].ToString()) * iW[position];
43
44             }
45             //加权和 除以 11 所得的余数为实验码对应余数.
46             return theSum % 11;
47         }
48     }
49 }