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How to copy files in C# with a customizable progress indicator and or progress bar

, 22 May 2009 CPOL
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This article shows you how to construct a class to copy files and folder trees with an optional progress indicator.

Copy Files


After reading about lots of ways to copy files with a progress indicator in C# and finding them all to be a little... long winded, I decided to write this article to help my fellow coders. It's a simple way to copy files and folders with a customizable progress bar/indicator.


The class uses the Windows Kernal32 CopyFileEx function to do the copying of files. This being said, it does use one pointer, and so needs to be compiled with the /unsafe parameter (or simply tick the 'allow unsafe code' option in the project's properties)

You can create your own way to display the progress of the copy. To do this, simply implement the ICopyFileDiag interface and pass your class to the copy method.

//The interface for the Dialog the CopyFiles class uses.
public interface ICopyFilesDiag
    //needed to sync the CopyClass update events with the dialog thread
    System.ComponentModel.ISynchronizeInvoke SynchronizationObject { get; set; }

    //This event should fire when you want to cancel the copy
    event CopyFiles.DEL_cancelCopy EN_cancelCopy;

    //This is how the CopyClass will send your dialog information about
    //the transfer
    void update(Int32 totalFiles, Int32 copiedFiles, Int64 totalBytes, 
                Int64 copiedBytes, String currentFilename);
    void Show();
    void Hide();

Using the code

The guts of the code is in the CopyFiles class; however, once this is referenced in your application, it's simply a case of specifying a list of files for a directory to copy and the location to copy it to.

You then choose to do the copy asynchronously or synchronously:

private void But_CopyFiles_Click(object sender, EventArgs e)

    //This the list of random files we want 
    //to copy into a single new directory
    List<String> TempFiles = new List<String>();
    TempFiles.Add("C:\\Copy Test Folder\\test.txt");
    TempFiles.Add("C:\\Copy Test Folder\\Bob.txt");
    TempFiles.Add("C:\\Copy Test Folder\\Test4\\Bob.Trev.txt");
    TempFiles.Add("C:\\Copy Test Folder\\Test4\\test.txt");
    TempFiles.Add("C:\\Copy Test Folder\\Test3\\Bob.Trev.txt");
    TempFiles.Add("C:\\Copy Test Folder\\Test3\\test.txt");
    TempFiles.Add("C:\\Copy Test Folder\\Test3\\B.o.b.Trev..txt");
    TempFiles.Add("C:\\Copy Test Folder\\Test2\\Bob.Trev.txt");
    TempFiles.Add("C:\\Copy Test Folder\\Test2\\test.txt");
    TempFiles.Add("C:\\Copy Test Folder\\Test1\\test.txt");
    TempFiles.Add("C:\\Copy Test Folder\\Test1\\B.o.b.Trev..txt");
    TempFiles.Add("C:\\Copy Test Folder\\Test1\\Bob.Trev.txt");

    //I would recommend you put at least one large file in this folder
    //to see the progress bar in action.
    CopyFiles.CopyFiles Temp = new CopyFiles.CopyFiles(TempFiles, "C:\\Test");
    //Uncomment the next line to copy the file tree.
    //CopyFiles.CopyFiles Temp = 
    // new CopyFiles.CopyFiles("C:\\Copy Test Folder", "C:\\Test");

    //Create the default Copy Files Dialog window from our Copy Files assembly
    //and sync it with our main/current thread
    CopyFiles.DIA_CopyFiles TempDiag = new CopyFiles.DIA_CopyFiles();
    TempDiag.SynchronizationObject = this;

    //Copy the files anysncrinsuly

    //Uncomment this line to do a synchronous copy.


This is an example of how the ICopyFileDiag can be implemented:

public partial class DIA_CopyFiles : Form, ICopyFilesDiag
    // Properties
    public System.ComponentModel.ISynchronizeInvoke 
           SynchronizationObject { get; set; }
    // Constructors
    public DIA_CopyFiles()
    // Methods
    public void update(Int32 totalFiles, Int32 copiedFiles, 
           Int64 totalBytes, Int64 copiedBytes, String currentFilename)
        Prog_TotalFiles.Maximum = totalFiles;
        Prog_TotalFiles.Value = copiedFiles;
        Prog_CurrentFile.Maximum = 100;
        if (totalBytes != 0)
            Prog_CurrentFile.Value = Convert.ToInt32((100f / 
                  (totalBytes / 1024f)) * (copiedBytes / 1024f));
        Lab_TotalFiles.Text = "Total files (" + copiedFiles + 
                  "/" + totalFiles + ")";
        Lab_CurrentFile.Text = currentFilename;
    private void But_Cancel_Click(object sender, EventArgs e)
    private void DIA_CopyFiles_Closed(object sender, System.EventArgs e)
    private void RaiseCancel()
        if (EN_cancelCopy != null)
    public event CopyFiles.DEL_cancelCopy EN_cancelCopy;


This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


About the Author

Neil Cadman

United Kingdom United Kingdom
No Biography provided

Comments and Discussions

QuestionHow to copy complete directory? PinmemberMember 110410572-Sep-14 1:53 
QuestionCopy and Rename? PinmemberElSEEDY3-Jun-14 5:33 
QuestionUser Control copyComplete Event Pinmemberarbh8915-Nov-12 7:33 
QuestionUpdated Code Pinmemberjtitley3-Oct-11 19:50 
QuestionRe: Updated Code Pinmemberscooter_seh7-Apr-12 7:47 
AnswerRe: Updated Code Pinmemberzt08194913-Nov-12 17:40 
GeneralRe: Updated Code Pinmemberscooter_seh14-Nov-12 2:28 
GeneralRe: Updated Code Pinmemberzt08194914-Nov-12 3:52 
QuestionCopy also empty folders Pinmemberlozirion10-Feb-11 1:04 
AnswerRe: Copy also empty folders PinmemberGary Noter7-Jul-11 9:20 
Generalfolder structure Pinmemberpavelnt26-Nov-10 1:24 
GeneralMy vote of 5 PinmemberB.V.Papadopoulos6-Sep-10 2:06 
GeneralError Handling Pinmembermason.c2-Jun-10 11:45 
QuestionCopyfolder for me does not work with large files PinmemberNadeem Rasool15-Apr-10 6:15 
AnswerRe: Copyfolder for me does not work with large files PinmemberNeil Cadman4-May-10 10:49 
GeneralCool article! PinmemberAbhinav S27-Mar-10 22:01 
QuestionVery helpful but I would like to copy an entire tree of files and folder. Pinmemberkakaomocha26-Mar-10 10:05 
AnswerRe: Very helpful but I would like to copy an entire tree of files and folder. PinmemberNeil Cadman4-May-10 10:52 
GeneralRe: Very helpful but I would like to copy an entire tree of files and folder. PinmemberNeil Cadman4-May-10 11:02 
GeneralRe: Very helpful but I would like to copy an entire tree of files and folder. Pinmembernasermokkary18-May-10 0:40 
GeneralRe: Very helpful but I would like to copy an entire tree of files and folder. PinmemberGary Noter7-Jul-11 9:23 
GeneralVery helpful! Pinmemberkolluti11-Mar-10 7:20 
GeneralMy vote of 1 Pinmemberkurtkc9-Mar-10 17:15 
QuestionTrouble with events EV_copyCanceled and EV_copyComplete Pinmemberjpangamarca18-Dec-09 7:06 
AnswerRe: Trouble with events EV_copyCanceled and EV_copyComplete PinmemberNeil Cadman3-Jan-10 9:48 

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