Question

您好我正在尝试为FTP图片上传添加进度条，虽然我在互联网上查看了很多示例，但我尝试过很多东西，但是我无法使用以下代码。我想要一个进度条来跟踪上传的进度，然后在完成后显示100％。

我的编码：

   Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

            Dim s As String = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
            Static r As New Random
            Dim sb As New StringBuilder
            For i As Integer = 1 To 8
                Dim idx As Integer = r.Next(0, 35)
                sb.Append(s.Substring(idx, 1))
            Next

            Clipboard.SetText("http://my-site.com/osdf/" + sb.ToString() + ".png")


            Using ms As New System.IO.MemoryStream
                sc.CaptureDeskTopRectangle(Me.boundsRect).Save(ms, System.Drawing.Imaging.ImageFormat.Png)

                ''Close()
                Using wc As New System.Net.WebClient
                    AddHandler wc.UploadDataCompleted, AddressOf UploadCompleted
                    wc.UploadData("ftp://USERNAME:PASSWORD@My-site.com/pic/uploads/" + sb.ToString() + ".png", ms.ToArray())

                End Using
                MsgBox("File Uploaded", MsgBoxStyle.Information)
            End Using

        End Sub

我如何使用我的代码执行此操作？

提前致谢，我将非常感谢您的支持。

Answer 1

更改您的代码并使用WebClient事件，如：

Using wc As New System.Net.WebClient
    AddHandler wc.UploadDataCompleted, AddressOf wc_UploadDataCompleted
    AddHandler wc.UploadProgressChanged, AddressOf wc_UploadProgressChanged
    wc.UploadData("ftp://USERNAME:PASSWORD@My-site.com/pic/uploads/" & sb.ToString() & ".png", ms.ToArray())
End Using

你还需要：

Private Sub wc_UploadDataCompleted(sender As Object, e As System.Net.UploadDataCompletedEventArgs) 
    MsgBox("File Uploaded", MsgBoxStyle.Information)
End Sub

Private Sub wc_UploadProgressChanged(sender As Object, e As System.Net.UploadProgressChangedEventArgs)
    ProgressBar1.Value = e.ProgressPercentage
End Sub

您需要使用“UploadDataAsync”而不是“UploadData”才能看到进度条中的增量或使用带有UploadData方法的BackgroundWorker。

ftp上传的VB.NET进度条

1 个答案: