Path operates on the path string Get the suffix Can merge paths Get file name

Directory and DirectoryInfo operate on the directory Determine if the directory exists Create a directory Delete the directory Gets all the subdirectories under the directory Gets all the subfiles in the directory

File and FileInfo operate on files Read the file Write files Additional documents Determine if the file exists Create a file Delete the file

1, Path class

using System;
using System.IO;// The namespace for directory and file operations
namespace _11_Path class  {
class Program {
static void Main(string[] args) {
string path = "c:\\abc\\1.txt" ;
// Notice that this is an operation on a path string   Not the actual document   "Modify" supports the string level, without actually renaming the file
path = Path.ChangeExtension(path, "avi" );//ChangeExtension() Modify the file suffix name 1.avi c:\\abc\\1.avi
// Combine the two paths 1 Two paths + Ok, it's easy to solve the problem of whether or not to add slashes, and automatically handle the problem of path separators
path = Path.Combine("c:\\abc\\def\\" , "1.jpg"); //c:\abc\def\1.jpg
// Get the location of the file in the folder   Again, from the point of view of strings
path = Path.GetDirectoryName(path);//c:\abc
path = Path.GetExtension(path);// extension  .txt
path = Path.GetFileName(path);// The file name . suffix  1.txt
path = Path.GetFileNameWithoutExtension(path);// File name without suffix  1
path = Path.GetFullPath("11-Path class .exe" );// File full path ( The full path of the relative file  1 This method is usually not used ) F:\PIZIYIMAO\11-Path class \bin\Debug\11-Path class .exe
path = Path.GetTempFileName();// The temporary folder saves the path   Automatic file creation  C:\Documents and Settings\PIZIYIMAO\Local Settings\Temp\tmp5E.tmp
path = Path.GetTempPath();// Gets the temporary folder save path  C:\Documents and Settings\PIZIYIMAO\Local Settings\Temp\
Console.WriteLine(path);
Console.Read();
}
}
}

2. Operate the directory classes Directory and DirectoryInfo

using System;
using System.IO;
namespace _12_Directory {
class Program {
static void Main( string[] args) {
DirectoryInfo dic = new DirectoryInfo( "c:\\abc" );
//dic.Name; // Get file name
//dic.FullName; // Gets the full path to the file   Function than Directory strong   The difference is that it is an instance class   The latter is a static class
Directory .CreateDirectory("c:\\abc" ); // Create folders
Directory .CreateDirectory("c:\\abc\\1\\2\\3\\4\\5\\6\\7" ); // Continuously create multiple levels of folders
if (Directory .Exists( "c:\\abc")) // Determine if a folder exists
{
Directory .Delete("c:\\abc" ); // Delete if it exists   If the folder is empty, it can be deleted normally   If it is not empty, it will report an error  " The directory is not empty "
Directory .Delete("c:\\abc" , true); //true Specifies the   If the folder is not empty   Perform the same delete operation
}
string [] paths = Directory .GetDirectories( "c:\\abc"); // Gets the names of all subdirectories in the directory   Just take it off 1 level   namely c:\abc\1  Such as access to windows This method can be used for all folder paths under folders
string [] paths2 = Directory .GetDirectories( "c:\\windows", "$*" );// The above method overload implementation   Searching for $ Opening file
string [] paths3 = Directory .GetDirectories( "c:\\abc", "*" , SearchOption .AllDirectories);// Wildcards look for qualified files in folders   Includes subfolders
foreach (string path in paths) {
Console .WriteLine(path);
}
string [] files = Directory .GetFiles( "c:\\windows"); // Walk through all the files in the folder
string [] files2 = Directory .GetFiles( "c:\\windows", "*.ini" , SearchOption .AllDirectories);// Wildcards look up files in directories   Usage is similar to GetDirectories
foreach (string file in files2) {
Console .WriteLine(file);
}
// The most important thing about directory operations is that  GetFiles and GetDirectories methods
Directory .GetParent("c:\\abc\\1\\2\\3\\4\\5\\6\\7" ); // return 7 The parent directory of the folder  c:\abc\1\2\3\4\5\6
Console .Read();
}
}
}

3. File File

using System;
using System.IO;
using System.Text;
namespace _13_File {
class Program {
static void Main( string[] args) {
//file Static class   use file Class to be aware of the use of file default encoding   If the encoding is incorrect   Garbled code will appear in the file
File .AppendAllText("c:\\1.txt" , "gb1232"); // to c:\\1.txt Append to file   Content" gb2312 "
// If there is a write file
if (File .Exists( "c:\\1.txt")) {
File .WriteAllText("c:\\1.txt" , " Writing in Chinese can sometimes appear garbled   Need to use regulation 3 A parameter   The specified Encoding The encoding format of the file  Default Is the default format " ,Encoding .Default);//WriteAllText It's complete coverage   while AppendAllText Is additional
}
//File.ReadAllText();// Read files are no longer enumerated   The following method of viewing a document is no longer an example
//string[] ReadAllLines(string path) // Reads the text file into an array of strings
//string ReadAllText(string path) // Reads the text file into the string
//WriteAllLines(string path,string[] contents) . // Saves the array of strings line by line to a file path In, the old content will be overwritten.
FileInfo fi = new FileInfo( "c:\\2.txt" );// Instantiated class   Function than file More powerful
fi.AppendText(); // It has many ways   And attributes   Their view   The document
Console .Read();
}
}
}