c# - Understanding Stream.Write Method to overwrite existing text -

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i used streamwriter write records file. want overwrite specific record.

string file="c:\\......"; streamwriter sw = new streamwriter(new filestream(file, filemode.open, fileaccess.write)); sw.write(...); sw.close();

i read somewhere here can use stream.write method that, have no previous experience or knowledge of how deal bytes. 

 public override void write(     byte[] array,     int offset,     int count )

what have string how use method. need explain byte[] array , int count are, , simple sample code shows how use method overwrite existing record in file.

ex. have record mark1287,11100,25| change bill9654,22100,30| .

if want override particular record, must use filestream.seek-method set put stream in position.

example seek

using system; using system.io;  class fstream { static void main() {     const string filename = "test#@@#.dat";      // create random data write file.     byte[] dataarray = new byte[100000];     new random().nextbytes(dataarray);      using(filestream           filestream = new filestream(filename, filemode.create))     {         // write data file, byte byte.         for(int = 0; < dataarray.length; i++)         {             filestream.writebyte(dataarray[i]);         }          // set stream position beginning of file.         filestream.seek(0, seekorigin.begin);          // read , verify data.         for(int = 0; < filestream.length; i++)         {             if(dataarray[i] != filestream.readbyte())             {                 console.writeline("error writing data.");                 return;             }         }         console.writeline("the data written {0} " +             "and verified.", filestream.name);     } } }

after having sought position, use write, whereas

public override void write( byte[] array, int offset, int count )  parameters array type: system.byte[] buffer containing data write stream. offset  type: system.int32 zero-based byte offset in array begin copying bytes stream.  count type: system.int32 maximum number of bytes write.

and important: consider documentation when unsure!


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