. NET implement string base64 encoding

usingSystem;usingSystem.Text;usingSystem.IO;usingsystem.security;usingSystem.Security.Cryptography; namespaceTgnet.Base.Security {/**//// <summary>     ///related operations for BASE64 encoding algorithms/// </summary>     /// <example>The following example Base64 encodes a string and returns the encoded string:/// <code>     ///Public string ToBase64 (String str) {///return Security.Base64.EncodingString (str); ///        }     /// </code>     /// </example>      Public classBase64 {/**//// <summary>         ///encrypt strings using the base64 algorithm/// </summary>         /// <param name= "sourcestring" >string to encrypt</param>         /// <param name= "Ens" >System.Text.Encoding objects, such as creating a Chinese encoding set object:///System.Text.Encoding.GetEncoding ("gb2312")</param>         /// <returns>encoded text string</returns>          Public Static stringEncodingstring (stringsourcestring,system.text.encoding Ens) {             returnconvert.tobase64string (Ens.getbytes (sourcestring)); }           /**//// <summary>         ///Use the default code page to encrypt strings using the base64 algorithm/// </summary>         /// <param name= "sourcestring" >string to encrypt</param>         /// <returns>the encrypted text string</returns>          Public Static stringEncodingstring (stringsourcestring) {             returnencodingstring (Sourcestring,system.text.encoding.default); }           /**//// <summary>         ///restores a string from a base64 encoded string, supports Chinese/// </summary>         /// <param name= "base64string" >Base64 the encrypted string</param>         /// <param name= "Ens" >System.Text.Encoding objects, such as creating a Chinese encoding set object:///System.Text.Encoding.Default</param>         /// <returns>the restored text string</returns>          Public Static stringDecodingstring (stringbase64string,system.text.encoding Ens) {             returnens.getstring ((convert.frombase64string (base64string))); }           /**//// <summary>         ///restores a string from a Base64 encoded string using the default code page, which supports Chinese/// </summary>         /// <param name= "base64string" >Base64 the encrypted string</param>         /// <returns>the restored text string</returns>          Public Static stringDecodingstring (stringbase64string) {              returndecodingstring (Base64string,system.text.encoding.default); }           /**//// <summary>         ///Base64 encodes a file and returns the encoded string/// </summary>         /// <param name= "strFileName" >path and filename of the file</param>         /// <returns>BASE64 encoded string for a file</returns>          Public Static stringEncodingfiletostring (stringstrFileName) {System.IO.FileStream FS=System.IO.File.OpenRead (strFileName); System.IO.BinaryReader BR=NewSystem.IO.BinaryReader (FS); stringBase64string=convert.tobase64string (Br. Readbytes ((int) fs.                       Length)); Br.             Close (); Fs.             Close (); returnbase64string; }             /**//// <summary>         ///Base64 encodes a file and writes the encoded content to a file/// </summary>         /// <param name= "Strsourcefilename" >file address to encode, support for any type of file</param>         /// <param name= "Strsavefilename" >the file path to write to</param>         /// <returns>If the write succeeds, returns the true</returns>          Public Static BOOLEncodingfiletofile (stringStrsourcefilename,stringstrsavefilename) {             stringstrbase64=encodingfiletostring (strsourcefilename); System.IO.StreamWriter FS=NewSystem.IO.StreamWriter (strsavefilename); Fs.             Write (STRBASE64); Fs.             Close (); return true; }           /**//// <summary>         ///decodes and stores Base64 encoded strings into a file/// </summary>         /// <param name= "base64string" >string after BASE64 encoding</param>         /// <param name= "Strsavefilename" >the file path to output, if the file exists, will be rewritten</param>         /// <returns>returns True if the operation is successful</returns>          Public Static BOOLDecodingfilefromstring (stringBase64string,stringstrsavefilename) {System.IO.FileStream FS=NewSystem.IO.FileStream (strsavefilename,system.io.filemode.create); System.IO.BinaryWriter BW=NewSystem.IO.BinaryWriter (FS); Bw.             Write (convert.frombase64string (base64string)); //bw. Write (convert.tobase64string)bw.             Close (); Fs.             Close (); return true; }           /**//// <summary>         ///decodes and stores a file generated by the BASE64 encoding into a file/// </summary>         /// <param name= "Strbase64filename" >files stored in BASE64 encoded format</param>         /// <param name= "Strsavefilename" >the file path to output, if the file exists, will be rewritten</param>         /// <returns>returns True if the operation is successful</returns>          Public Static BOOLDecodingfilefromfile (stringStrbase64filename,stringstrsavefilename) {System.IO.StreamReader FS=NewSystem.IO.StreamReader (STRBASE64FILENAME,SYSTEM.TEXT.ENCODING.ASCII); Char[] base64chararray=New Char[FS.             Basestream.length]; Fs. Read (Base64chararray,0,(int) fs.             Basestream.length); stringbase64string=New string(Base64chararray); Fs.             Close (); returndecodingfilefromstring (base64string,strsavefilename); }           /**//// <summary>         ///get files from network address one and convert to Base64 encoding/// </summary>         /// <param name= "strURL" >the URL address of the file, which must be an absolute URL address</param>         /// <param name= "Objwebclient" >System.Net.WebClient Object</param>         /// <returns>returns a BASE64 encoded Web resource string</returns>          Public Static stringEncodingwebfile (stringstrurl,system.net.webclient objwebclient) {             returnconvert.tobase64string (Objwebclient.downloaddata (strURL)); }           /**//// <summary>         ///get files from network address one and convert to Base64 encoding/// </summary>         /// <param name= "strURL" >the URL address of the file, which must be an absolute URL address</param>         /// <returns>returns a BASE64 encoded Web resource string</returns>          Public Static stringEncodingwebfile (stringstrURL) {             returnEncodingwebfile (strURL,NewSystem.Net.WebClient ()); }     } }