Question

我想在ProgressBar上显示下载过程的进度。我尝试过像this code for upload这样的事情，但我失败了。这是我尝试失败的一个例子

private void button5_Click(object sender, EventArgs e)
{
    Task.Run(() => Download());
}

private void Download()
{
    try
    {
        int Port = (int)numericUpDown1.Value;
        string Host = comboBox1.Text;
        string Username = textBox3.Text;
        string Password = textBox4.Text;
        string SourcePath = textBox5.Text;
        string RemotePath = textBox6.Text;
        string FileName = textBox7.Text;

        using (var file = File.OpenWrite(SourcePath + FileName))
        using (var Stream = new FileStream(SourcePath + FileName, FileMode.Open))
        using (var Client = new SftpClient(Host, Port, Username, Password))
        {
            Client.Connect();
            progressBar1.Invoke((MethodInvoker)
            delegate
            {
                progressBar1.Maximum = (int)Stream.Length;
            });
            Client.DownloadFile(RemotePath + FileName, /*file*/ Stream, DownloadProgresBar);
            Client.Disconnect();
        }
    }
    catch (Exception Ex)
    {
        System.Windows.Forms.MessageBox.Show(Ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
    }
}
private void DownloadProgresBar(ulong Downloaded)
{
    progressBar1.Invoke((MethodInvoker)
        delegate
        {
            progressBar1.Value = (int)Downloaded;
        });
}

提前谢谢

Answer 1

正如您所做的那样，与displaying progress of file upload的代码类似，您必须回复SftpClient.DownloadFile的downloadCallback参数。

public void DownloadFile(string path, Stream output, Action<ulong> downloadCallback = null)

您也可以在后台线程上正确下载。或者，您可以使用异步上载（SftpClient.BeginDownloadFile）。

出了什么问题，需要改变：

您必须打开/创建本地文件以进行书写（FileMode.Create）。
您必须检索远程文件的大小，而不是本地大小（尚不存在）。使用SftpClient.GetAttributes。

使用后台线程（任务）的示例：

private void button1_Click(object sender, EventArgs e)
{
    // Run Download on background thread
    Task.Run(() => Download());
}

private void Download()
{
    try
    {
        int Port = 22;
        string Host = "example.com";
        string Username = "username";
        string Password = "password";
        string RemotePath = "/remote/path/";
        string SourcePath = @"C:\local\path\";
        string FileName = "download.txt";

        using (var stream = new FileStream(SourcePath + FileName, FileMode.Create))
        using (var client = new SftpClient(Host, Port, Username, Password))
        {
            client.Connect();
            SftpFileAttributes attributes = client.GetAttributes(RemotePath + FileName);
            // Set progress bar maximum on foreground thread
            progressBar1.Invoke(
                (MethodInvoker)delegate { progressBar1.Maximum = (int)attributes.Size; });
            // Download with progress callback
            client.DownloadFile(RemotePath + FileName, stream, DownloadProgresBar);
            MessageBox.Show("Download complete");
        }
    }
    catch (Exception e)
    {
        MessageBox.Show(e.Message);
    }
}

private void DownloadProgresBar(ulong uploaded)
{
    // Update progress bar on foreground thread
    progressBar1.Invoke((MethodInvoker)delegate { progressBar1.Value = (int)uploaded; });
}

上传请参阅：
Displaying progress of file upload in a ProgressBar with SSH.NET

使用SSH.NET在ProgressBar中显示文件下载的进度

1 个答案: