C # File operations,

C # File operations,

FileClass is a static class, mainly used to provide some function libraries.The static objects class provides many static methods that support basic file operations, including creating, copying, moving, deleting, and opening a file.FileThe parameters of class methods are mostly paths.Path.FileSome methods can returnFileStreamAndStreamWriter. They can be used together.

The System. IO. File class and System. IO. FileInfo class provide various operations on files. The System. IO namespace must be referenced during use. The following describes the main attributes and methods of a program instance.

(1)File opening method:File. Open ()

The statement of this method is as follows:

public static FileStream Open(string path,FileMode mode) 

The following code opens the file named newfile.txt in the c: \ tempuploadsdirectory and writes hello to the file.

private void OpenFile(){　FileStream.TextFile=File.Open(@"c:\tempuploads\newFile.txt",FileMode.Append);　byte [] Info = {(byte)'h',(byte)'e',(byte)'l',(byte)'l',(byte)'o'};　TextFile.Write(Info,0,Info.Length);　TextFile.Close();}

(2)File Creation method:File. Create ()

The statement of this method is as follows:

public static FileStream Create(string path;)

 

The following code demonstrates how to create a file named newfile.txt under c: \ tempuploads.
Because File. by default, the Create method grants all users full read/write access to the new file. Therefore, the file is opened with the read/write access permission, which must be disabled before it can be opened by other applications. Therefore, you must use the Close method of the FileStream class to Close the created file.

private void MakeFile(){ 　    FileStream NewText=File.Create(@"c:\tempuploads\newFile.txt");　NewText.Close();}　

(3)File Deletion method:File. Delete ()

The method is declared as follows:

public static void Delete(string path);

The following code deletes the newfile.txt file in the c: \ tempuploadsdirectory.

private void DeleteFile(){　File.Delete(@"c:\tempuploads\newFile.txt");}

(4)File Replication method:File. Copy

The method is declared as follows:

public static void Copy(string sourceFileName,string destFileName,bool overwrite);

The following code copies c: \ tempuploads \ newFile.txt to c: \ tempuploads \ BackUp.txt.
The overwritegion of copetypes is set to true, so that if the backup.txt file already exists, it will be overwritten by the copied file.

private void CopyFile(){　File.Copy(@"c:\tempuploads\newFile.txt",@"c:\tempuploads\BackUp.txt",true);}

(5)File movement method:File. Move

The method is declared as follows:

public static void Move(string sourceFileName,string destFileName); 

The following code moves the backup.txt file under c: \ tempuploadsto the c root directory.

Note:
File Transfer can only be performed on the same logical disk. If you try to transfer files from drive C to drive D, an error will occur.

private void MoveFile(){　File.Move(@"c:\tempuploads\BackUp.txt",@"c:\BackUp.txt");}

(6)How to Set file attributes:File. SetAttributes
 

The method is declared as follows:

public static void SetAttributes(string path,FileAttributes fileAttributes);

The following code sets the properties of file c: \ tempuploads \ newFile.txt to read-only and hidden.

private void SetFile(){　File.SetAttributes(@"c:\tempuploads\newFile.txt",　FileAttributes.ReadOnly|FileAttributes.Hidden);}

In addition to common read-only and hidden attributes, files include Archive, System, and Temporary. For details about file attributes, see the description of FileAttributes in MSDN.

(7)To determine whether a file exists:File. Exist
 

The method is declared as follows:

public static bool Exists(string path); 

The following code checks whether the c: \ tempuploads \ newFile.txt file exists. If the file exists, copy the file first, delete it, and then move the copied file. If the file does not exist, create the file first, open the file, and write the file, finally, set the file attribute to read-only and hidden.

If (File. exists (@ "c: \ tempuploads \ newFile.txt") // checks whether the file Exists {CopyFile (); // copies the file DeleteFile (); // deletes the file MoveFile (); // move file} else {MakeFile (); // generate file OpenFile (); // open the file SetFile (); // set file attributes}

In addition, the File class provides more support for Text.

· AppendText: append text to an existing file.
· CreateText: Creates or opens a new file for writing text.
· OpenText: open an existing text file for reading.

But the above method mainly on the UTF-8 encoding text operations, which is not flexible enough. We recommend that you use the following code to operate the txt file.
· Read the txt file. The sample code is as follows:

StreamReader TxtReader = new StreamReader(@"c:\tempuploads\newFile.txt",System.Text.Encoding.Default);string FileContent;FileContent = TxtReader.ReadEnd();TxtReader.Close();

· Perform the "write" Operation on the txt file. The sample code is as follows:

StreamWriter = new StreamWrite(@"c:\tempuploads\newFile.txt",System.Text.Encoding.Default);string FileContent;TxtWriter.Write(FileContent);TxtWriter.Close(); 

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