File Operations, file operations

File Operations, file operations

1. Using the C # program to read and write a file requires the following five basic content:

① Create a file stream

② Create a reader or writer

③ Perform read/write operations

④ Close the reader or writer

⑤ Close the file stream

 

2. using System. IO: This namespace is used to process files and file streams.

3. Create: Create a file with the specified name. If the file exists, rewrite the old file.

CreateNew: Create a new file. If the file exists, an exception occurs, prompting that the file already exists.

Open: Open a file. When this enumeration value is used, the specified file must exist; otherwise, an exception occurs.

OpenOrCreate: OpenOrCreate is similar to the Open member, but if the file does not exist, create a file with the specified name and Open it.

Append: open an existing file and Append content to the end of the file.

 

4. close the file stream

Close myfs. Close ();

5. StreamWrite Writer:

StreamWrite. Write ():Used to write a stream. This stream is the created stream.

StreamWrite. WriteLine (): used to write a row of data, which is followed by a line break.

StreamWrite. Close (): used to Close the writer.

6. StreamReader

StreamReader is mainly used to read data in a stream. It mainly includes the following methods:

StreamReader. ReadLine (): reads a row of data in the file stream and returns a string

StreamReader. ReadToEnd (): reads the end from the current position and returns a string.

StreamReader. Close (): used to Close the reader

 

7. The Encoding class is located in the System. Text namespace and used to indicate character Encoding.

① The Encoding format can be specified through static members of the Encoding class. For example:

Encoding. UTF8: gets the Encoding in UTF-8 format.

Encoding. Default: Get the current Encoding of the Operating System

② You can also use the static method GetEncoding (string name) of the Encoding class to specify the character Encoding. The parameter name must be the supported Encoding name of C #. For example:

StreamReader mySr = new StreamReader (myfs, Encoding. GetEncoding ("GB520 "));

8. File and Directory

 

9. Differences between static fish and non-static fish

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Static | non-static

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Use static modifier | do not use static Modifier

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Contains only static members | can contain static members.

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It cannot contain instance members. | it can contain instance members.

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Call static members by class name | call non-static members by Instance Object

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Cannot be instantiated | can be instantiated

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The instance constructor cannot be included. | the instance constructor is included.

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10. attributes and methods of the FileInfo class

Attribute

Exists: used to check whether the specified file Exists. A boolean value is returned.

Extension: gets a string that represents the file Extension.

Name: get the file Name

FullName: Obtain the complete directory or file

 

Return Value Type Method

FileInfo CopyTo (string): Copies an existing file to a new file. The existing file cannot be overwritten.

Void Delete (): Permanently deletes an object.

Void MoveTo (string): Move the specified file to a new location (string)

 

11. Two important methods of the DirectoryInfo class:

① GetDirectories (): This method returns an array of subdirectory objects in the current directory.

② GetFiles (): This method returns the current directory and file list (FileInfo object array ).

 

12.