c# - 在 C#4 中向 ProgressChanged 事件添加额外参数

Question

这是我的代码(简单下载器):

public void DownloadFile(string urlAddress, string location)
    {
        using (webClient = new WebClient())
        {
            webClient.DownloadFileCompleted += new AsyncCompletedEventHandler(Completed);
            webClient.DownloadProgressChanged += new DownloadProgressChangedEventHandler(ProgressChanged);
            Uri URL = urlAddress.StartsWith("http://", StringComparison.OrdinalIgnoreCase) ? new Uri(urlAddress) : new Uri("http://" + urlAddress);
            try
            {
                webClient.DownloadFileAsync(URL, location);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
    }

这是我的问题:

如何向我的 ProgressChanged 事件添加额外参数 (int RowNumber)？我的意思是这样的:

private void ProgressChanged(object sender, DownloadProgressChangedEventArgs e, int RowNumber)
    {
           // Other codes here
    }

& 这是 VS2010 给我的错误:

No overload for 'ProgressChanged' matches delegate 'System.Net.DownloadProgressChangedEventHandler'

我应该重写DownloadProgressChangedEventHandler吗？!怎么办？!

感谢您帮助我。

Answer 1

您应该更改此设置:

webClient.DownloadProgressChanged += new DownloadProgressChangedEventHandler(ProgressChanged);

与:

webClient.DownloadProgressChanged += new DownloadProgressChangedEventHandler((sender, e) => ProgressChanged(sender, e, RowNumber));