December 03, 2013
Provides instance methods for the creation, copying, deletion, moving, and opening of files, and aids in the creation of FileStream objects. This class cannot be inherited.
Assembly: mscorlib (in mscorlib.dll)
Thetype exposes the following members.
|Attributes||Gets or sets the FileAttributes of the current FileSystemInfo. (Inherited from FileSystemInfo.)|
|CreationTime||Gets or sets the creation time of the current FileSystemInfo object. (Inherited from FileSystemInfo.)|
|Directory||Gets an instance of the parent directory.|
|DirectoryName||Gets a string representing the directory's full path.|
|Exists||Gets a value indicating whether a file exists. (Overrides FileSystemInfo.Exists.)|
|Extension||Gets the string representing the extension part of the file. (Inherited from FileSystemInfo.)|
|FullName||Gets the full path of the directory or file. (Inherited from FileSystemInfo.)|
|LastAccessTime||Gets or sets the time the current file or directory was last accessed. (Inherited from FileSystemInfo.)|
|LastWriteTime||Gets or sets the time when the current file or directory was last written to. (Inherited from FileSystemInfo.)|
|Length||Gets the size, in bytes, of the current file.|
|Name||Gets the name of the file. (Overrides FileSystemInfo.Name.)|
|AppendText||Creates a StreamWriter that appends text to the file represented by this instance of the .|
|CopyTo(String)||Copies an existing file to a new file, disallowing the overwriting of an existing file.|
|CopyTo(String, Boolean)||Copies an existing file to a new file, allowing the overwriting of an existing file.|
|Create||Creates a file.|
|CreateText||Creates a StreamWriter that writes a new text file.|
|Delete||Permanently deletes a file. (Overrides FileSystemInfo.Delete.)|
|Equals(Object)||Determines whether the specified Object is equal to the current Object. (Inherited from Object.)|
|Finalize||Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)|
|GetHashCode||Serves as a hash function for a particular type. (Inherited from Object.)|
|GetType||Gets the Type of the current instance. (Inherited from Object.)|
|MemberwiseClone||Creates a shallow copy of the current Object. (Inherited from Object.)|
|MoveTo||Moves a specified file to a new location, providing the option to specify a new file name.|
|Open(FileMode)||Opens a file in the specified mode.|
|Open(FileMode, FileAccess)||Opens a file in the specified mode with read, write, or read/write access.|
|Open(FileMode, FileAccess, FileShare)||Opens a file in the specified mode with read, write, or read/write access and the specified sharing option.|
|OpenRead||Creates a read-only FileStream.|
|OpenText||Creates a StreamReader with UTF8 encoding that reads from an existing text file.|
|OpenWrite||Creates a write-only FileStream.|
|Refresh||Refreshes the state of the object. (Inherited from FileSystemInfo.)|
|ToString||Returns the path as a string. (Overrides Object.ToString.)|
Use the class for typical operations such as copying, moving, renaming, creating, opening, deleting, and appending to files.
Many of the methods return other I/O types when you create or open files. You can use these other types to further manipulate a file. For more information, see specific members such as Open, OpenRead, OpenText, CreateText, or Create.
If you are going to reuse an object several times, consider using the instance method of instead of the corresponding static methods of the File class, because a security check will not always be necessary.
In members that accept a path as an input string, that path must be well-formed or an exception is raised. For example, if a path is fully qualified but begins with a space, the path is not trimmed in methods of the class. Therefore, the path is malformed and an exception is raised. Similarly, a path or a combination of paths cannot be fully qualified twice. For example, "c:\temp c:\windows" also raises an exception in most cases. Ensure that your paths are well-formed when using methods that accept a path string.
In members that accept a path, the path can refer to a file or just a directory.
The class provides the following properties that enable you to retrieve information about a file. For an example of how to use each property, see the property pages.
The Directory property retrieves an object that represents the parent directory of a file.
The DirectoryName property retrieves the full path of the parent directory of a file.
The Exists property checks for the presence of a file before operating on it.
The Length retrieves the size of a file.
The Name retrieves the name of a file.
The following example displays an image picked at random from the user's My Pictures folder. It uses the DirectoryInfo class to obtain an enumerable collection of objects that represent files that have a .jpg or .png extension. That collection is used to construct a List(Of T) collection so that its index can be used to select a file that corresponds to the random number.
Private Sub LoadImage() Dim di As New DirectoryInfo(Environment.GetFolderPath(Environment.SpecialFolder.MyPictures)) Dim files = From f In di.EnumerateFiles() _ Where f.Extension.ToLower() = ".jpg" OrElse f.Extension = ".png" _ Select f Dim max As Integer = files.Count() + 1 Dim rnd As New Random() Dim r As Integer = rnd.[Next](0, max) Dim pics As New List(Of FileInfo)(files) Dim randpic As String = pics(r).FullName Dim img As New BitmapImage() img.SetSource(New FileStream(randpic, FileMode.Open)) MyImage.Source = img End Sub