抛出异常的原因是http协议默认的并发访问量是2,但是当长时间访问网络不好,或者数据量较大的路径时候就会很快消耗完访问次数,所以解决办法如下(另外附上一个简单的下载方法,网上多的是):、
System.Net.ServicePointManager.DefaultConnectionLimit = 999;(999这个数字是随便写的,一般情况下512就够了,最大建议不要超过1024)
///
///下载方法
///serverPath为网络要下载的路径
public static void Download(string serverPath) { WebClient client = new WebClient(); HttpWebRequest myRequest = null; string fileName = "概预算表.xls";//被下载的文件名 serverPath= "另存为路径" + fileName;//另存为地址 FileStream writeStream = new FileStream(path, FileMode.Append, FileAccess.Write, FileShare.ReadWrite); try { myRequest = (HttpWebRequest)HttpWebRequest.Create(serverPath);//url地址 http://****** System.Net.ServicePointManager.DefaultConnectionLimit = 999;/*---------这里最重要--------*/ Stream readStream = myRequest.GetResponse().GetResponseStream(); byte[] btArray = new byte[512]; int contentSize = readStream.Read(btArray, 0, btArray.Length); while (contentSize > 0) { writeStream.Write(btArray, 0, contentSize); contentSize = readStream.Read(btArray, 0, btArray.Length); } //GC.Collect(); GC.WaitForPendingFinalizers(); //关闭流 writeStream.Close(); readStream.Close(); } catch (Exception ex) { writeStream.Close(); System.Windows.Forms.MessageBox.Show(ex.Message, "提示"); } }