Stephens' C# Programming with Visual Studio® 2010 24-Hour Trainer

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LESSON 30 Using File system Classes

PROPERTY PURPOSE

IsReadOnly

Returns true if the file is marked read-only.

LastAccessTime

The time at which the file was last accessed.

LastWriteTime

The time at which the file was last written.

Length

The file’s size in bytes.

Name

The file’s name without the path.

Example program UseFileInfo (found in this lesson’s code download) uses a FileInfo object to

display information about files.

THE FILE CLASS

The File class provides static methods for manipulating files (see Table 30-7). For simple tasks

these are sometimes easier to use than the comparable

FileInfo class methods because you don’t

need to create a

FileInfo object to use them. The AppendAllText, ReadAllLines, ReadAllText,

WriteAllLines, and WriteAllText methods are particularly useful for reading and writing text

files all at once, although you may still want to use

StreamReader and StreamWriter if you need

to manipulate files one line at a time.

TABLE 307

METHOD PURPOSE

AppendAllText

Appends a string to the end of a file.

Copy

Copies a file to a new file.

Create

Creates a file.

Decrypt

Decrypts a file that was encrypted by the Encrypt method.

Delete

Deletes a file.

Encrypt

Encrypts the file so it can only be read by the account used to encrypt it.

Exists

Returns true if a file exists.

GetAttributes

Returns a file’s attributes, such as ReadOnly, System, or Hidden.

GetCreationTime

Returns the time at which the file was created. ...