Question

我在C＃中有拨号程序。如果正在下载/上传，我想更改图像。如何在以下代码中添加此类检查？

private void UpdateNetworkInterface()
    {
        this.Invoke((MethodInvoker)delegate
        {
            NetworkInterface nic = nicArr[cmbInterface.SelectedIndex];
            IPv4InterfaceStatistics interfaceStats = nic.GetIPv4Statistics();
            long lngBytesSent = 0;
            long lngBtyesReceived = 0;
            int bytesSentSpeed = (int)(interfaceStats.BytesSent - lngBytesSent) /1024;
            int bytesReceivedSpeed = (int)(interfaceStats.BytesReceived - lngBtyesReceived) /1024;
            // Update the labels
            lblInterfaceType.Text = nic.NetworkInterfaceType.ToString();
            lblUpload.Text = bytesSentSpeed.ToString() + " KB";
            lblDownload.Text = bytesReceivedSpeed.ToString() + " KB";
            //this.StatusTextBox.AppendText(string.Format("{0}\r\n\r\n DOWNLOAD/UPLOAD in progress", ""));
        });
    }

Answer 1

您可以使用System.Net.WebClient来执行此操作。

它有一个事件DownloadProgressChanged，它有参数，它有包含下载字节和文件总字节数的字段。

由WebClient.DownloadFileAsync()触发。

MSDN链接：https://msdn.microsoft.com/en-us/library/system.net.webclient(v=vs.110).aspx

示例：

private void DownloadChanged(object sender, DownloadProgressChangedEventArgs e)
{
    labelProgress.Text = string.Format("{0} Percents Completed",
                 e.BytesReceived / e.TotalBytesToReceive * 100);

}

private void StartDownload(object sender, EventArgs e) // Button Event
{
    var webClient = new WebClient();
    webClient.DownloadProgressChanged += new DownloadProgressChangedEventHandler(DownloadChanged);
    webClient.DownloadFileAsync(/* URL */);
}

获取上传字节与下载一个相同。快乐编程！：）

Answer 2

这些属性为您提供转移的总字节数，您需要的是该数字的衍生物（变化率）。

最简单的方法就是做简单的数学问题

所以你需要录音然后比较这两点以获得速度。

private long _lastBytesRecevied;
private long _lastBytesSent;
private DateTime _lastReceivedMesurement;
private DateTime _lastSentMesurement;

//This needs to be done once at the start of the class to "seed" the first value.
private Init()
{
    _lastReceivedMesurement = DateTime.UtcNow;
    _lastBytesRecevied = interfaceStats.BytesReceived;

    _lastSentMesurement = DateTime.UtcNow;
    _lastBytesSent = interfaceStats.BytesSent;
}

private double getKBDownloadSpeed()
{
    double result = (interfaceStats.BytesReceived - _lastBytesRecevied) / (DateTime.UtcNow -  _lastReceivedMesurement).TotalSeconds;

   _lastReceivedMesurement = DateTime.UtcNow;
   _lastBytesRecevied = interfaceStats.BytesReceived;

   return result / 1024d;
}

private double getKBUploadSpeed()
{
   double result = (interfaceStats.BytesSent - _lastBytesSent) / (DateTime.UtcNow - _lastSentMesurement).TotalSeconds;

  _lastSentMesurement = DateTime.UtcNow;
  _lastBytesSent = interfaceStats.BytesSent;

   return result / 1024d;
}

现在，您的两个函数返回上次调用函数和当前调用之间的平均下载速度。

如果您获得下载速度的价值，请将图像更改为下载图标。如果您获得上传速度的值，请将图像更改为上传图标。

此致

Thiyagu Rajendran

**如果有帮助，请将回复标记为答案。

C＃检查下载上传字节是否大于

2 个答案: