Base64 encoding class source code (C #)

Using system; namespace shapbse64 {// <summary> // base64 encoding Algorithm Related Operations // by free Pentium (wgscd) /// </Summary> public class sbase64 {public sbase64 () {// todo: here, add the constructor logic //} // encrypt /// <summary> // use base64 to encrypt the string /// </Summary> /// <Param name = "sourcestring"> string to be encrypted </param> // <Param name = "ens"> system. text. encoding object. For example, create a Chinese sequence set object: system. text. encoding. getencoding (54936) </param> // <returns> encoded text string </returns> Public static string encodingforstring (string sourcestring, system. text. encoding ENS) {return convert. tobase64string (ENS. getbytes (sourcestring ));} /// <summary> /// use base64 to encrypt the string /// </Summary> /// <Param name = "sourcestring"> string to be encrypted </Param >/// <returns> encoded text string </returns> Public static string encodingforstring (string sourcestring) {return encodingforstring (sourcestring, system. text. encoding. getencoding (54936);} // <summary> // restores a string from a base64 encoded string, supports Chinese characters /// </Summary> /// <Param name = "base64string"> base64-encrypted string </param> /// <Param name = "ens"> system. text. encoding object. For example, create a Chinese sequence set object: system. text. encoding. getencoding (54936) </param> // <returns> restored text string </returns> Public static string decodingforstring (string base64string, system. text. encoding ENS) {/************************************** * *********************** the byte value obtained from base64string is the character's internal code (ANSI character encoding) * generally, it is the formula to convert the data into Chinese characters using the internal code: * (char) (first byte binary value * 256 + second byte value) * Because the char or string in C # adopts unicode encoding, it cannot be used to calculate * ANSI Byte encoding and Unicode encoding incompatibility * according to the above formula.. Net Class Library provides the encoding class implementation from ANSI encoding to Unicode Code ** The getencoding method relies on the basic platform to support most code pages. However, system support is provided for: default encoding, that is, the encoding specified in the locale settings of the computer on which this method is executed; little-Endian Unicode (UTF-16LE ); big-Endian Unicode (UTF-16BE); Windows operating system (Windows-1252); UTF-7; UTF-8; ASCII and gb18030 (Simplified Chinese ). ** Specify a name listed in the following table to obtain the encoding supported by the system with the corresponding code page. ** Code Page name * 1200 UTF-16LE, UTF-16, ucs-2, Unicode, or ISO-10646-UCS-2 * 1201 UTF-16BE or unicodefffe * 1252 windows-1252 "* 65000" utf-7 "," csunicode11utf7 "," unicode-1-1-utf-7 "," unicode-2-0-utf-7 "," X-unicode-1-1-utf-7 "or" x-unicode-2-0-utf-7 "* 65001" UTF-8 "," unicode-1-1-utf-8 "," unicode-2-0-utf-8 ""," x-unicode-1-1-utf-8 "or" x-unicode-2-0-utf-8 "* 20127" US-ASCII "," us "," ASCII "," ANSI_X3.4-1968 "," ANSI _ X3.4-1986, cp367, csascii, ibm367, iso-ir-6, ISO646-US, or iso_646.irv: 1991 "* 54936" gb18030 "** some platforms may not support specific code pages. For example, the Japanese shift-JIS code page (code page 932) may not be supported in Windows 98 in the US ). In this case, the getencoding method will trigger notsupportedexception when executing the following C # code: ** encoding ENC = encoding. getencoding ("shift-JIS "); **************************************** * ******************* // obtain the original character return ens from base64string. getstring (convert. frombase64string (base64string);} // <summary> // restores the string from a base64 encoded string, supports Chinese characters /// </Summary> /// <Param name = "base64string"> base64-encrypted string </param> /// <returns> restored text string </returns> Public static string decodingforstring (string base64string) {return decodingforstring (base64string, system. text. encoding. getencoding (54936 ));} /// encode /// <summary> /// encode any type of file with base64 /// </Summary> /// <Param name = "FILENAME"> path and file name </param> /// <returns> base64-encoded string </returns> Public static string encodingforfile (string filename) {system. io. filestream FS = system. io. file. openread (filename); system. io. binaryreader BR = new system. io. binaryreader (FS);/* system. byte [] B = new system. byte [FS. length]; FS. read (B, 0, convert. toint32 (FS. length); */string base64string = convert. tobase64string (BR. readbytes (INT) FS. length); BR. close (); FS. close (); Return base64string ;} /// <summary> /// Save the base64 encoded string as a file // </Summary> /// <Param name = "base64string"> after base64 encoding </param> /// <Param name = "FILENAME"> Save the file path and file name </param> /// <returns> whether the file is saved successfully </returns> Public static bool savedecodingtofile (string base64string, string filename) {system. io. filestream FS = new system. io. filestream (filename, system. io. filemode. create); system. io. binarywriter BW = new system. io. binarywriter (FS); BW. write (convert. frombase64string (base64string); BW. close (); FS. close (); Return true ;} // summary /// <summary> /// obtain the file from network address 1 and convert it to base64 encoding /// </Summary> /// <Param name = "url"> File URL, an absolute URL </param> // <Param name = "objwebclient"> system. net. webClient object </param> /// <returns> </returns> Public static string encodingfilefromurl (string URL, system. net. webClient objwebclient) {return convert. tobase64string (objwebclient. downloaddata (URL ));} /// <summary> /// obtain the file from network address 1 and convert it to base64 encoding /// </Summary> /// <Param name = "url"> URL address, an absolute URL address </param> // <returns> converts the object to a base64 string </returns> Public static string encodingfilefromurl (string URL) {// system. net. webClient mywebclient = new system. net. webClient (); Return encodingfilefromurl (URL, new system. net. webClient ());}}}