Introduction to FileStream class of C ＃

FileStream class

FileStream( File stream ) This class is mainly used for reading and writing binary files , You can also use it to read and write any file .

StreamReader( Stream reader ) and StreamWriter( Stream writer ) Dedicated to reading and writing text files

Use FileStream Read write binary :
FileStream Instance is used to read and write data in a file , To construct FileStream example , You need to provide the following 4 In the information ：

1. File to access
   Generally, the full pathname of a file is provided
2. Mode indicating how to open the file
   Create a new file or open an existing file , If you open an existing file , The write operation is to overwrite the original contents of the file , Or append to the end of the file ？
3. Indicates how to access the file
   read-only 、 Just write 、 Or read and write
4. share access
   Indicates whether to have exclusive access to the file , If other streams are allowed to access files at the same time , Then these streams are read-only Just write Or read and write files

---

Arguments to the constructor ：

• FileMode( Turn on mode ) Append,Create,CreateNew,Open,OpenOrCreate and Truncate
• FileAccess( Read or write ) Read,ReadWrite and Write
• FileShare( File sharing settings ) Delete,Inheritable,None,Read,ReadWrite and Write

PS：
If the file doesn't exist Append Open and Truncate It throws an exception , If the file exists CreateNew It throws an exception ; Create and OpenOrCreate：Create Will delete existing files , Create a new empty file ,OpenOrCreate It will judge whether there are files currently , If not, it will create ;

matters needing attention ：
When we finish using a stream , Be sure to call fs.Close(); Method to close the flow , Closing the flow frees the resources associated with it , Allow other applications to set up streams for the same file . This operation will also flush the buffer .

---

Sample code

using System;
using System.IO;
using System.Text;

namespace CSharpDemo
{
    
    class Programma
    {
    
        static void Main(string[] args)
        {
    
            string path = @"E:\MyTest.txt";
            if (File.Exists(path)) //  Verify that the file exists 
            {
    
                File.Delete(path);
            }
           
            //  Create and write files 
            using (FileStream fs_write = File.Create(path))
            {
    
                byte[] info = new UTF8Encoding(true).GetBytes("123");
                fs_write.Write(info, 0, info.Length);
                byte[] info1 = new UTF8Encoding(true).GetBytes("456789");
                fs_write.Write(info1, 0, info1.Length);
            }

            //  Read the file 
            using (FileStream fs_read = File.OpenRead(path))
            {
    
                byte[] byteArr = new byte[1024];
                UTF8Encoding coding = new UTF8Encoding(true);
                while (fs_read.Read(byteArr, 0, byteArr.Length) > 0)
                {
    
                    Console.WriteLine(coding.GetString(byteArr));
                }
            }
            Console.ReadKey();
        }
    }
}