Статья
11/18/2011

FileInfo Class

Microsoft Silverlight will reach end of support after October 2021. Learn more.

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.

Inheritance Hierarchy

System.Object
System.IO.FileSystemInfo
System.IO.FileInfo

Namespace: System.IO
Assembly: mscorlib (in mscorlib.dll)

Syntax

'Declaration
<ComVisibleAttribute(True)> _
Public NotInheritable Class FileInfo _
    Inherits FileSystemInfo

[ComVisibleAttribute(true)]
public sealed class FileInfo : FileSystemInfo

The FileInfo type exposes the following members.

Constructors

	Name	Description
	FileInfo	When it is called by trusted applications, initializes a new instance of the FileInfo class, which acts as a wrapper for a file path.

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Properties

	Name	Description
	Attributes	When called by trusted applications, gets or sets the FileAttributes of the current FileSystemInfo. (Inherited from FileSystemInfo.)
	CreationTime	When called by trusted applications, gets or sets the creation time of the current FileSystemInfo object. (Inherited from FileSystemInfo.)
	Directory	When it is called by trusted applications, gets an instance of the parent directory.
	DirectoryName	When it is called by trusted applications, 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	When called by trusted applications, gets the full path of the directory or file. (Inherited from FileSystemInfo.)
	LastAccessTime	When called by trusted applications, gets or sets the time the current file or directory was last accessed. (Inherited from FileSystemInfo.)
	LastWriteTime	When called by trusted applications, 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.)

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Methods

	Name	Description
	AppendText	When it is called by trusted applications, creates a StreamWriter that appends text to the file represented by this instance of the FileInfo.
	CopyTo(String)	When it is called by trusted applications, copies an existing file to a new file, disallowing the overwriting of an existing file.
	CopyTo(String, Boolean)	When it is called by trusted applications, copies an existing file to a new file, allowing the overwriting of an existing file.
	Create	When it is called by trusted applications, creates a file.
	CreateText	When it is called by trusted applications, creates a StreamWriter that writes a new text file.
	Delete	When it is called by trusted applications, 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	When it is called by trusted applications, moves a specified file to a new location, providing the option to specify a new file name.
	Open(FileMode)	When it is called by trusted applications, opens a file in the specified mode.
	Open(FileMode, FileAccess)	When it is called by trusted applications, opens a file in the specified mode with read, write, or read/write access.
	Open(FileMode, FileAccess, FileShare)	When it is called by trusted applications, 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	When it is called by trusted applications, 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().)

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Fields

	Name	Description
	FullPath	Infrastructure. Represents the fully qualified path of the directory or file. (Inherited from FileSystemInfo.)
	OriginalPath	Infrastructure. The path originally specified by the user, whether relative or absolute. (Inherited from FileSystemInfo.)

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Examples

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 FileInfo objects that represent files that have a .jpg or .png extension. That collection is used to construct a List<T> collection so that its index can be used to select a file that corresponds to the random number.

The example then creates a bitmap image by using the FileStream class and sets it as the source for an Image control (named myImage).

For example code and information about how to create an application that runs outside the browser, see Out-of-Browser Support.

Private Sub LoadImage()

    If Application.Current.HasElevatedPermissions Then
        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 If
End Sub

private void LoadImage()
{

    if (Application.Current.HasElevatedPermissions)
    {
        DirectoryInfo di = new DirectoryInfo(Environment.GetFolderPath(
           Environment.SpecialFolder.MyPictures));

        var files = from f in di.EnumerateFiles()
                    where f.Extension.ToLower() == ".jpg" || 
                        f.Extension == ".png"
                    select f;

        int max = files.Count() + 1;

        Random rnd = new Random();
        int r = rnd.Next(0, max);

        List<FileInfo> pics = new List<FileInfo>(files);

        string randpic = pics[r].FullName;

        BitmapImage img = new BitmapImage();
        img.SetSource(new FileStream(randpic, FileMode.Open));

        MyImage.Source = img;

    }
}

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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