About FileStream reading large file issues

Small text files (100M or less) directly using the ReadAllText () and WriteAllText () methods of the File class
The interior of these two methods is essentially the writetoend () that encapsulates the StreamReader class of ReadToEnd () and the StreamWriter class,
The return values of both methods are of type string, so only text files can be read and written

Small text file single-line read-write with StreamReader and StreamWriter these two classes

Small non-text files are read and written using the file class's ReadAllBytes () and WriteAllBytes () and byte[] as a broker
The inside of these two methods is actually encapsulating the FileStream's read () and write () methods,
The return values of both methods are byte arrays, so you can read and write any file

Large file
However, file read and write Jumbo file is error, because it is essentially using FileStream to read and write, but its byte[] size is written dead (that is, the size of the file is read and write), so it is to read or write the file all at once, the file is very large often cause memory overflow, So we have to use the data flow FileStream, because we can define the size of byte[] freely, to ensure that the memory does not overflow

In general, read files with FileMode.Open, write files with the Filemode.create,filestream position attribute is a pointer to mark the current location of the file stream read and write
Code implementation:

1 using (FileStream fsread = new FileStream (@ "D:\Names.txt", FileMode.Open)) 2 {3 using (FileStream fswrite = new Filestr EAM (@ "D:\temp.txt", FileMode.Create)) 4 {5 byte[] arr = new byte[200]; 6//record exactly how many bytes of data were read 7 int count = 0; 8 while (Fsrea D.position < Fsread.length) 9 {10//per read,. Returns the number of bytes actually read, using the Count record (which may count after the last read) by Count = Fsread.read (arr, 0, arr). LENGTH); 12//writes the data in the array to the specified file Fswrite.write (arr, 0, Count);}15}16 MessageBox.Show ("OK"); 17}

Knot

First look at the size of the file-if it is a large file with FileStream, if it is a small file to see whether it is a text file-non-text files are used in the file class Readallbytes/writeallbytes, is a text file to see whether it is a single-line read and write- Is the StreamReader class/streamwriter class, not the readalltext/writealltext of the file class

In addition, any type of file can be read and written using FileStream.

About FileStream reading large file issues