Windows apps
Collapse the table of content
Expand the table of content
Information
The topic you requested is included in another documentation set. For convenience, it's displayed below. Choose Switch to see the topic in its original location.

FileInfo::Exists Property

 

Gets a value indicating whether a file exists.

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

public:
property bool Exists {
	virtual bool get() override;
}

Property Value

Type: System::Boolean

true if the file exists; false if the file does not exist or if the file is a directory.

When first called, FileInfo calls Refresh and caches information about the file. On subsequent calls, you must call Refresh to get the latest copy of the information.

The Exists property returns false if any error occurs while trying to determine if the specified file exists. This can occur in situations that raise exceptions such as passing a file name with invalid characters or too many characters, a failing or missing disk, or if the caller does not have permission to read the file.

The following code example uses the Exists property ensure a file exists before opening it. You can use this technique to throw a custom exception when the file is not found.

array<Byte>^ Openfile(String^ fileName)
{
    // Check the fileName argument.
    if (fileName == nullptr || fileName->Length == 0)
    {
        throw gcnew ArgumentNullException("fileName");
    }

    // Check to see if the file exists.
    FileInfo^ fInfo = gcnew FileInfo(fileName);

    // You can throw a personalized exception if
    // the file does not exist.
    if (!fInfo->Exists)
    {
        throw gcnew FileNotFoundException("The file was not found.",
            fileName);
    }

    try
    {
        // Open the file.
        FileStream^ fStream = gcnew FileStream(fileName, FileMode::Open);

        // Create a buffer.
        array<Byte>^ buffer = gcnew array<Byte>(fStream->Length);

        // Read the file contents to the buffer.
        fStream->Read(buffer, 0, (int)fStream->Length);

        // return the buffer.
        return buffer;
    }
    catch (IOException^ ex)
    {
        Console::WriteLine(ex->Message);
        return nullptr;
    }
}

Universal Windows Platform
Available since 10
.NET Framework
Available since 1.1
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Return to top
Show:
© 2017 Microsoft