Compress the guid to 26 bits using a 36-digit system.

Msdn explanation:

GUID is a 128-bit integer (16 bytes) that can be used on all computers and networks that require a unique identifier. This identifier is unlikely to be repeated.

Uint64 indicates a 64-bit unsigned integer. Value Type indicates an unsigned integer between 0 and 18,446,744,073,709,551,615.

The principle is to split the guid into two 64-bit uint64 characters, and then convert the uint64 into a 36-digit character format.

The maximum value of uint64 is converted to 36 in hexadecimal notation of 13 BITs. Therefore, the generated characters are 26 characters in length.

ConversionCodeAs follows:

/// <Summary> /// Brief description of convert36 /// </Summary> public class convert36 {public convert36 () {// todo: add the constructor logic here //} private const string base_char = "0123456789 abcdefghijklmnopqrstuvwxyz"; // convert it to the segment character Private Static string getlongno (uint64 num, int length) {string STR = ""; while (Num> 0) {int cur = (INT) (Num % 36); STR = base_char [cur] + STR; num = num/36;} If (Str. length> length) {STR = Str. substring (Str. le Ngth-length);} else {STR = Str. padleft (length, '0');} return STR;} // resolution segment character Private Static uint64 getlongnum (string strno) {uint64 num = 0; For (INT I = 0; I <strno. length; I ++) {num + = (uint64) base_char.indexof (strno [I]) * (uint64) math. pow (base_char.length, strno. length-I-1);} return num ;} /// <summary> /// compress the guid /// </Summary> /// <Param name = "G"> </param> /// <returns> </returns> Public static string get Guidno (guid g) {string S = G. tostring (). replace ("-",""). toupper (); string S1 = S. substring (0, 16); string S2 = S. substring (16); uint64 L1 = uint64.parse (S1, system. globalization. numberstyles. hexnumber); uint64 L2 = uint64.parse (S2, system. globalization. numberstyles. hexnumber); string str1 = getlongno (L1, 13); string str2 = getlongno (L2, 13); Return str1 + str2 ;} /// <summary> /// obtain the guid /// </Summary> /// <p Aram name = "str"> </param> // <returns> </returns> Public static guid getguid (string Str) {If (Str. length! = 26) {Throw new exception ("string error! The length must be 26 characters! ");} String S1 = Str. substring (0, 13); string S2 = Str. substring (13); uint64 L1 = getlongnum (S1); uint64 L2 = getlongnum (S2); string str1 = l1.tostring ("X "); string str2 = l2.tostring ("X"); string strguid = str1.padleft (16, '0'); strguid + = str2.padleft (16, '0 '); guid G = new GUID (strguid); Return g ;}}

Instance download: http://files.cnblogs.com/zjfree/Convert36.rar