C#进度条不'；下载时不更新

我正在使用BackgroundWorker从ftp服务器下载一个文件，但只有在文件下载完成后，进度才会更新

进度条保持为0，在下载期间冻结，并设置为100

这是我的密码：

    private void backgroundWorker1_DoWork(object sender, System.ComponentModel.DoWorkEventArgs e) {
        FtpWebRequest request = (FtpWebRequest)WebRequest.Create(activeDownload.ftpPath);
        request.Credentials = new NetworkCredential(ftpUser, ftpPass);
        request.Method = WebRequestMethods.Ftp.DownloadFile;

        FtpWebResponse response = (FtpWebResponse)request.GetResponse();
        Stream responseStream = response.GetResponseStream();

        using (FileStream writer = new FileStream(activeDownload.localPath, FileMode.Create)) {

            long length = response.ContentLength;
            int bufferSize = 2048;
            int readCount;
            byte[] buffer = new byte[2048];
            long bytesread = 0;
            backgroundWorker1.ReportProgress(0);

            readCount = responseStream.Read(buffer, 0, bufferSize);
            while (readCount > 0) {
                bytesread += readCount;
                writer.Write(buffer, 0, readCount);
                backgroundWorker1.ReportProgress((int)(bytesread / activeDownload.fileSize) * 100);
                readCount = responseStream.Read(buffer, 0, bufferSize);
            }
        }

        response.Close();
        responseStream.Close();
    }

    private void backgroundWorker1_ProgressChanged(object sender, System.ComponentModel.ProgressChangedEventArgs e) {
        progressBar1.Value = e.ProgressPercentage;
    }

---

我做错了什么？任何帮助都将不胜感激。

设置值，然后在下面运行

progressbar1.PerformStep()

你也可以

progressBar1.Refresh()

---

设置该值，然后在下面运行

progressbar1.PerformStep()

你也可以

progressBar1.Refresh()

---

查看以下链接是否有帮助：

及

下面是我在一个项目中实现的示例代码：

public ProcessFilesClass()
    {
        InitializeComponent();
        backgroundWorker1= new BackgroundWorker();
        backgroundWorker1.DoWork += new DoWorkEventHandler(backgroundWorker1_DoWork);
        backgroundWorker1.RunWorkerCompleted += new RunWorkerCompletedEventHandler(backgroundWorker1_RunWorkerCompleted);
        backgroundWorker1.ProgressChanged += new ProgressChangedEventHandler(backgroundWorker1_ProgressChanged);
    }

private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
    {
        BackgroundWorker worker = sender as BackgroundWorker;
        var backgroundWorker = sender as BackgroundWorker;
        worker.WorkerReportsProgress = true;
        WorkerProcessMethod();
    }

private void WorkerProcessMethod()
    {
            //Process items in list box
            int itemsToProcess = someListBox.Items.Count;
            for (int i = 0; i < itemsToProcess; i++)
                {
                    int findPercentage = ((i + 1) * 100) / someListBox.Items.Count;
                     if (backgroundWorker1 != null) { backgroundWorker1.ReportProgress(findPercentage, null); }
                }
    }

private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
    {
           progressBar1.Value = e.ProgressPercentage;

    }

private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
          //DisableProgressBarStatus
           this.Close();            
    }

publicprocessFileClass（）
{
初始化组件（）；
backgroundWorker1=新的BackgroundWorker（）；
backgroundWorker1.DoWork+=新的DoWorkerVenthandler（backgroundWorker1_DoWork）；
backgroundWorker1.RunWorkerCompleted+=新的RunWorkerCompletedEventHandler（backgroundWorker1\U RunWorkerCompleted）；
backgroundWorker1.ProgressChanged+=新的ProgressChangedEventHandler（backgroundWorker1\u ProgressChanged）；
}
私有void backgroundWorker1\u DoWork（对象发送方，DoWorkEventArgs e）
{
BackgroundWorker worker=发件人作为BackgroundWorker；
var backgroundWorker=发送方作为backgroundWorker；
worker.WorkerReportsProgress=true；
WorkerProcessMethod（）；
}
私有void WorkerProcessMethod（）
{
//处理列表框中的项目
int itemsToProcess=someListBox.Items.Count；
for（int i=0；i

查看以下链接是否有帮助：

及

下面是我在一个项目中实现的示例代码：

public ProcessFilesClass()
    {
        InitializeComponent();
        backgroundWorker1= new BackgroundWorker();
        backgroundWorker1.DoWork += new DoWorkEventHandler(backgroundWorker1_DoWork);
        backgroundWorker1.RunWorkerCompleted += new RunWorkerCompletedEventHandler(backgroundWorker1_RunWorkerCompleted);
        backgroundWorker1.ProgressChanged += new ProgressChangedEventHandler(backgroundWorker1_ProgressChanged);
    }

private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
    {
        BackgroundWorker worker = sender as BackgroundWorker;
        var backgroundWorker = sender as BackgroundWorker;
        worker.WorkerReportsProgress = true;
        WorkerProcessMethod();
    }

private void WorkerProcessMethod()
    {
            //Process items in list box
            int itemsToProcess = someListBox.Items.Count;
            for (int i = 0; i < itemsToProcess; i++)
                {
                    int findPercentage = ((i + 1) * 100) / someListBox.Items.Count;
                     if (backgroundWorker1 != null) { backgroundWorker1.ReportProgress(findPercentage, null); }
                }
    }

private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
    {
           progressBar1.Value = e.ProgressPercentage;

    }

private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
          //DisableProgressBarStatus
           this.Close();            
    }

publicprocessFileClass（）
{
初始化组件（）；
backgroundWorker1=新的BackgroundWorker（）；
backgroundWorker1.DoWork+=新的DoWorkerVenthandler（backgroundWorker1_DoWork）；
backgroundWorker1.RunWorkerCompleted+=新的RunWorkerCompletedEventHandler（backgroundWorker1\U RunWorkerCompleted）；
backgroundWorker1.ProgressChanged+=新的ProgressChangedEventHandler（backgroundWorker1\u ProgressChanged）；
}
私有void backgroundWorker1\u DoWork（对象发送方，DoWorkEventArgs e）
{
BackgroundWorker worker=发件人作为BackgroundWorker；
var backgroundWorker=发送方作为backgroundWorker；
worker.WorkerReportsProgress=true；
WorkerProcessMethod（）；
}
私有void WorkerProcessMethod（）
{
//处理列表框中的项目
int itemsToProcess=someListBox.Items.Count；
for（int i=0；i

好的，结果证明我做的一切都很好，但我分析的百分比是错误的。除以两个long（bytesread和activeDownload.fileSize）返回0。因此，进展率一直停留在0%

以下是正确的解析：

backgroundWorker1.ReportProgress(Convert.ToInt32((((double)bytesread / activeDownload.fileSize) * 100)));

---

好吧，结果证明我做的一切都很好，但我分析的百分比是错误的。除以两个long（bytesread和activeDownload.fileSize）返回0。因此，进展率一直停留在0%

以下是正确的解析：

backgroundWorker1.ReportProgress(Convert.ToInt32((((double)bytesread / activeDownload.fileSize) * 100)));

---

请问这是一个什么样的项目？某些项目（如VSTO）在BGW中的行为与预期不符，需要其他功能才能正常工作。如果问题在于您提供给

ReportProgress

的信息或进度条呈现，您是否进行了调试？添加一些

Debug.WriteLine

+我们需要，我已经找到了解决办法。下面是更多的细节。你能说说这是一个什么样的项目吗？某些项目（如VSTO）在BGW中的行为与预期不符，需要其他功能才能正常工作。如果问题在于您提供给

ReportProgress

的信息或进度条呈现，您是否进行了调试？添加一些

Debug.WriteLine

+我们需要，我已经找到了解决办法。更多细节见下文。