How to cancel a file copy

[hdbbdh]

Hi,

I am trying to make Backup program, that copy files from one location to another one, but I don't know how to allow user to cancel this operation.

The code that I use is:

Public Class Form1
 
Private Delegate Function CopyProgressRoutine(ByVal totalFileSize As Int64, ByVal totalBytesTransferred As Int64, ByVal streamSize As Int64, ByVal streamBytesTransferred As Int64, ByVal dwStreamNumber As Int32, ByVal dwCallbackReason As Int32, ByVal hSourceFile As Int32, ByVal hDestinationFile As Int32, ByVal lpData As Int32) As Int32
 
Private Declare Auto Function CopyFileEx Lib "kernel32.dll" (ByVal lpExistingFileName As String, ByVal lpNewFileName As String, ByVal lpProgressRoutine As CopyProgressRoutine, ByVal lpData As Int32, ByVal lpBool As Int32, ByVal dwCopyFlags As Int32) As Int32
 
Private Function CopyProgress(ByVal totalFileSize As Int64, ByVal totalBytesTransferred As Int64, ByVal streamSize As Int64, ByVal streamBytesTransferred As Int64, ByVal dwStreamNumber As Int32, ByVal dwCallbackReason As Int32, ByVal hSourceFile As Int32, ByVal hDestinationFile As Int32, ByVal lpData As Int32) As Int32
ProgressBar1.Value = Convert.ToInt32(totalBytesTransferred / totalFileSize * 100)
End Function
 
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim cpr As New CopyProgressRoutine(AddressOf CopyProgress)
CopyFileEx("C:\myFile.dll", "D:\myFile.dll", cpr, 0, 0, 0)
End Sub
 
End Class

Thank you

[raids51]

you could use a filestream and a buffer instead, then copy it byte by byte. but this is slower then for example io.file.copy... . but you would have more control over the file, you could keep track of the progress, the speed that its being copied at and you could cancel or pause it.

[hdbbdh]

Thank you raids51,
Can you give me an example about that, because I am very fresh in programming.
Thank you

[hdbbdh]

Hi,

I think I found the solution

Public Class Form1
    Private Delegate Function CopyProgressRoutine(ByVal totalFileSize As Int64, ByVal totalBytesTransferred As Int64, ByVal streamSize As Int64, ByVal streamBytesTransferred As Int64, ByVal dwStreamNumber As Int32, ByVal dwCallbackReason As Int32, ByVal hSourceFile As Int32, ByVal hDestinationFile As Int32, ByVal lpData As Int32) As Int32
    Private Declare Auto Function CopyFileEx Lib "kernel32.dll" (ByVal lpExistingFileName As String, ByVal lpNewFileName As String, ByVal lpProgressRoutine As CopyProgressRoutine, ByVal lpData As Int32, ByVal lpBool As Int32, ByVal dwCopyFlags As Int32) As Int32
 
    Private Const COPY_FILE_RESTARTABLE As Long = &H2
    Private Const PROGRESS_CONTINUE As Long = 0
    Private Const PROGRESS_CANCEL As Long = 1
    Dim blnCancel As Boolean = False
    Private Function CopyProgress(ByVal totalFileSize As Int64, ByVal totalBytesTransferred As Int64, ByVal streamSize As Int64, ByVal streamBytesTransferred As Int64, ByVal dwStreamNumber As Int32, ByVal dwCallbackReason As Int32, ByVal hSourceFile As Int32, ByVal hDestinationFile As Int32, ByVal lpData As Int32) As Int32
        ProgressBar1.Value = Convert.ToInt32(totalBytesTransferred / totalFileSize * 100)
        Me.Text = ProgressBar1.Value
        Application.DoEvents()
        If blnCancel = True Then
            Return PROGRESS_CANCEL
        Else
            Return PROGRESS_CONTINUE
        End If
    End Function
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim cpr As New CopyProgressRoutine(AddressOf CopyProgress)
        CopyFileEx("C:\myFile.dll", "D:\myFile.dll", cpr, 0, blnCancel, 0)
    End Sub
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        blnCancel = True
    End Sub
End Class

Thank you