C# Signature:

[DllImport("kernel32.dll", CharSet = CharSet.Unicode)]
static extern bool CopyFile(string lpExistingFileName, string lpNewFileName, bool bFailIfExists);

[DllImport("kernel32.dll", CharSet = CharSet.Unicode, CallingConvention = CallingConvention.StdCall, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool CopyFile(
  [MarshalAs(UnmanagedType.LPWStr)]string lpExistingFileName,
  [MarshalAs(UnmanagedType.LPWStr)]string lpNewFileName,
  [MarshalAs(UnmanagedType.Bool)]bool bFailIfExists);

VB.NET Signature:

<DllImport("kernel32.dll", CharSet := CharSet.Unicode, CallingConvention := CallingConvention.StdCall, SetLastError := True)>
Shared Function CopyFile(<MarshalAs(UnmanagedType.LPWStr)> ByVal lpExistingFileName As String, <MarshalAs(UnmanagedType.LPWStr)> ByVal lpNewFileName As String, <MarshalAs(UnmanagedType.Bool)> ByVal bFailIfExists As Boolean) As <MarshalAs(UnmanagedType.Bool)> Boolean
End Function

User-Defined Types:

None.

Notes:

None.

Tips & Tricks:

Please add some!

Sample Code - C#

using System;
using System.Runtime.InteropServices;

namespace MyNamespace
{
    class Program
    {
        [DllImport("kernel32.dll")]
        static extern bool CopyFile(string lpExistingFileName, string lpNewFileName, bool bFailIfExists);

        /*
        lpExistingFileName - Source File
        lpNewFileName - Destination File

        bFailIfExists - Whether or not CopyFile will overwrite lpNewFileName if the file exists.
        If true, CopyFile will return false if lpNewFileName is an existing file. */

        static void Main(string[] args)
        {

            string SourceFile = "C:\\MySourceFile.txt"; // This file must exist or else CopyFile will fail and return false.
            string DestinationFile = "C:\\MyDestinatioFile.txt";

            if (CopyFile(SourceFile, DestinationFile, true))
            {
            // Your code here if CopyFile succeeds
            Console.WriteLine("File successfully copied.");
            } else
            {
            // Your code here if CopyFile fails
            Console.WriteLine("File could not be copied. The file already exists.");
            }

        }
    }
}

Alternative Managed API:

public static void System.IO.File.Copy(System.String sourceFileName , System.String destFileName , System.Boolean overwrite)

Please edit this page!

Do you have...

• helpful tips or sample code to share for using this API in managed code?
• corrections to the existing content?
• variations of the signature you want to share?
• additional languages you want to include?

Select "Edit This Page" on the right hand toolbar and edit it! Or add new pages containing supporting types needed for this API (structures, delegates, and more).