ASP.NET 魔法學院

Imports System.Runtime.InteropServices

Public Class Form1
    Private pbCancel As Int32

    <DllImport("kernel32.dll", CharSet:=CharSet.Auto)> _
    Private Shared Function CopyFileEx( _
        ByVal lpExistingFileName As String, _
        ByVal lpNewFileName As String, _
        ByVal lpProgressRoutine As CopyProgressRoutine, _
        ByVal lpData As IntPtr, _
        ByRef pbCancel As Int32, _
        ByVal dwCopyFlags As ECopyFileFlags) As Boolean
    End Function

    ''' <summary>
    ''' 執行 CopyFileEx 方法的回呼函式定義。
    ''' </summary>
    Delegate Function CopyProgressRoutine( _
        ByVal TotalFileSize As Long, _
        ByVal TotalBytesTransferred As Long, _
        ByVal StreamSize As Long, _
        ByVal StreamBytesTransferred As Long, _
        ByVal dwStreamNumber As UInteger, _
        ByVal dwCallbackReason As ECopyProgressCallbackReason, _
        ByVal hSourceFile As IntPtr, _
        ByVal hDestinationFile As IntPtr, _
        ByVal lpData As IntPtr) As ECopyProgressResult

    ''' <summary>
    ''' 執行 CopyFileEx 的回呼函式的回傳列舉。
    ''' </summary>
    Enum ECopyProgressResult As UInteger
        PROGRESS_CONTINUE = 0
        PROGRESS_CANCEL = 1
        PROGRESS_STOP = 2
        PROGRESS_QUIET = 3
    End Enum

    Enum ECopyProgressCallbackReason As UInteger
        CALLBACK_CHUNK_FINISHED = 0
        CALLBACK_STREAM_SWITCH = 1
    End Enum

    <Flags()> _
    Enum ECopyFileFlags As UInteger
        COPY_FILE_FAIL_IF_EXISTS = 1
        COPY_FILE_RESTARTABLE = 2
        COPY_FILE_OPEN_SOURCE_FOR_WRITE = 4
        COPY_FILE_ALLOW_DECRYPTED_DESTINATION = 8
    End Enum

    Private Function XCopy(ByVal oldFile As String, ByVal newFile As String) As Boolean
        Return CopyFileEx(oldFile, newFile, New CopyProgressRoutine(AddressOf Me.CopyProgressHandler), IntPtr.Zero, pbCancel, ECopyFileFlags.COPY_FILE_RESTARTABLE)
    End Function

    Private Function CopyProgressHandler(ByVal total As Long, ByVal transferred As Long, ByVal streamSize As Long, ByVal StreamByteTrans As Long, ByVal dwStreamNumber As UInteger, ByVal reason As ECopyProgressCallbackReason, _
     ByVal hSourceFile As IntPtr, ByVal hDestinationFile As IntPtr, ByVal lpData As IntPtr) As ECopyProgressResult
        Label1.Text = String.Format("進度: {0}%", CInt(transferred / total * 100))
        Application.DoEvents()

        Return ECopyProgressResult.PROGRESS_CONTINUE
    End Function

    Private Sub btnCopy_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCopy.Click
        If XCopy("C:\Source.avi", "D:\New.avi") Then
            MsgBox("複製成功")
        Else
            MsgBox("複製失敗")
        End If

    End Sub

    Private Sub btnCancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCancel.Click
        pbCancel = 1
        Application.DoEvents()
    End Sub
End Class