File.Copy Method (String, String, Boolean)

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

Copies an existing file to a new file. Overwriting a file of the same name is allowed.

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


Public Shared Sub Copy ( _
    sourceFileName As String, _
    destFileName As String, _
    overwrite As Boolean _
public static void Copy(
    string sourceFileName,
    string destFileName,
    bool overwrite


  • destFileName
    Type: System..::.String
    The name of the destination file. This cannot be a directory.
  • overwrite
    Type: System..::.Boolean
    true if the destination file can be overwritten; otherwise, false.


Exception Condition

The caller does not have the required permission.


sourceFileName or destFileName is a zero-length string, contains only white space, or contains one or more invalid characters as defined by GetInvalidPathChars.


sourceFileName or destFileName specifies a directory.


sourceFileName or destFileName is nullNothingnullptra null reference (Nothing in Visual Basic).


The specified path, file name, or both exceed the system-defined maximum length. For example, on Windows-based platforms, paths must be less than 248 characters, and file names must be less than 260 characters.


The path specified in sourceFileName or destFileName is invalid (for example, it is on an unmapped drive).


sourceFileName was not found.


destFileName is read-only, or destFileName exists and overwrite is false.


An I/O error has occurred.


sourceFileName or destFileName is in an invalid format.


Version Notes

Windows Phone

This member has a SecurityCriticalAttribute attribute. This attribute restricts this member to internal use. Application code that uses this member throws a MethodAccessException.

Version Information

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0


Windows Phone

See Also


File Class

Copy Overload

System.IO Namespace