File read/write and Data Processing

Happy New Year ;)

This isCodeThe example can be run directly, mainly including the processing of binary data streams and character data during file read/write.
In addition, I have written detailed comments for you to learn more conveniently.
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Using system; using system. net. networkinformation; using system. text; using system. io; namespace consoleapplication1 {class program {static void main (string [] ARGs) {binarywriteread (); // copy (); // console. writeline ("copied"); // txtread ();} // binary read/write Integrated Application (suitable for games such as data storage) // pay attention to static void binarywriteread () such as the memory change bytes in this instance {// write to the disk (in the memory, it is output because it is output to external devices) // In the operating system, stream is a filestream FS = file with memory as the reference. create ("Save"); system. io. binarywriter writer = new binarywriter (FS); random RDM = new random (); For (INT I = 0; I <10; I ++) // int32 4-byte x10 {int num = RDM. next (); writer. write (Num); console. writeline ("Write INTEGER: {0}", num);} Char [] DATA = {'h', 'E', 'l', 'l ', 'o'}; writer. write (data); console. writeline ("Write: Hello"); writer. write ('-'); // 46 bytes // write the ASCII code of 26 letters // If streamreader is used, the corresponding ASCII letter for (byte I = 97; I <97 + 26; I ++) writer. Write (I); console. writeline ("Write ~ Z "); writer. write ('\ n'); // 71-byte console. writeline ("----------------------------------------"); FS. flush (); FS. close (); writer. close (); // ------------------------------------------------------------- // read (input in memory) FS = file. openread ("save"); binaryreader reader = new binaryreader (FS); // read 26 letters FS. seek (46, seekorigin. begin); For (byte I = 97; I <97 + 26; I ++) console. write (reader. readchar (); // read Take 10 integers FS. seek (-72, seekorigin. current); console. writeline (); // int indicates system. int32 4 bytes // If writer. write (true) is actually written into one byte: 0x0001 // byte is the basic unit byte [] numdata = new byte [4]; for (INT I = 0; I <10; I ++) {reader. read (numdata, 0, 4); console. writeline ("read INTEGER: {0}", byteartolong (numdata); // manually convert the byte array // console. writeline ("read INTEGER: {0}", reader. readint32 ();} reader. close (); FS. close ();} static int getnu M (byte [] bytes) // convert binary to decimal (in my post, leave a comment on the brother's code which is awesome x ^_^) {// The long data type is 8 bytes int num = 0; int n = math. min (bytes. length, 4)-1; for (INT I = N; I>-1; I --) num = (Num <8) | bytes [I]; // num = (Num <8) + bytes [I]; return num;} // convert the byte array to a long integer (Binary to decimal) static long byteartolong (byte [] bytes) {// int [] Nums = {1,256,512,102, 2048, 4096,8192, 16384,32768, 65536,131072, 262144 }; // At that time, my code was written in this way. A big number may cause problems. The 8-byte value should be 8 square characters while I Write is indeed 2 square // but the above-mentioned Message expert only cares about his own happiness, such an obvious error is not seen // int srcdata = 312705998; // For example, the int value above is stored in the form of 0x12a383ce in the memory // but it is stored in the file in reverse (the low position is the top position and the back position is the top position) // if I read 4 bytes at a time, it is in the following format // byte [] DATA = {0xce, 0x83, 0xa3, 0x12 }; int [] Nums = {1,256,655 36, 16777216}; If (bytes. length> nums. length) throw new exception ("overflow"); long num = 0; For (INT I = 0; I <bytes. length; I ++) num + = (Bytes [I] * Nums [I]); Return num;} static void Copy () // file copy (Binary read/write) {filestream FS = file. openread ("D:/create a folder (2).zip"); fileinfo copys = new fileinfo ("D:/Appendix .zip"); filestream fscopy = copys. create (); byte [] DATA = new byte [10]; int Reds; while (Reds = FS. read (data, 0, Data. length)> 0) fscopy. write (data, 0, Reds); FS. flush (); fscopy. close (); FS. close ();} static void txtread () // text reading {// ANSI encoding is a tough thing. // For example, UTF-8 and other encoded text files will start with two bytes to recognize the encoding/ /While ANSI is not, but ANSI is expanded to include Chinese character encoding. // I tried to read binary and decode it before, but it is really troublesome. // still like this easy to be lazy) O Haha ~ Filestream FS = file. open (@ "D:/. CS ", filemode. open); streamreader reader = new streamreader (FS); string data; while (Data = reader. readline ())! = NULL) console. writeline (data );}}}