Question

我正在从网站下载一个大文件。

大小：= 599 MB（629,113,799字节）。

程序运行正常。但是我遇到了一些错误：

无法验证文件是否已完全下载。我没有在屏幕上看到任何显示

的消息

Console.WriteLine("..............File succesfully downloaded......This mesage comes from --  wc_DownloadFileCompleted..........");

所以程序会完全下载文件。（我确实使用网络浏览器手动下载了文件并进行了比较手动下载和下载的文件之间的文件大小通过该计划。大小是一样的。所以这对我来说是一个很好的理由相信程序确实完全下载了文件）

然而在最后（在显示百分比为99之后）它会抛出错误..这是消息

WebClient请求期间发生异常。

错误消息在wc_DownloadFileCompleted内被触发方法

所以我需要的帮助是......我们如何验证文件是否已下载完全（没有任何错误）？我们如何消除错误。

我是否可以使用其他代码而不是使用代码我提出了。
我确实在屏幕上看到了文件下载百分比99。但是我没有看到＆＃34; 100＆＃34;出现。有什么意见吗？

using System.Threading.Tasks;
using System;
using System.Data;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Collections.Generic;
using System.Text;
using System.Diagnostics;
using System.Reflection; //Need this to get the DEBUG path
using MHPUtil;
using System.Net;
using System.Globalization;

namespace CmsNpiFileLoad
{
    public static class FileDownLoadPercentage
    {
        //We need a global variable that will remain the same throughout the run.
        //The unique value for this variable will get set in the DownloadFile() method.
        public static string Value { get; set; }
    }

    class CMsNPIFileDownLoad
    {
        //599 MB (629,113,799 bytes) is the size of the file.

        public void DownloadCMSNPIFile()
        {

            string Destinationfile = "S:\\MIS\\Provider NPI file\\" + "NPI.zip";
            string CmsDownLoadSite = "http://download.cms.gov/nppes/NPPES_Data_Dissemination_January_2018.zip";

            //Is the INTERNET AVAILABLE 
            if (System.Net.NetworkInformation.NetworkInterface.GetIsNetworkAvailable())
            {
                Console.WriteLine("Internet available, proceed with the download");
            }
            else
            {
                Console.WriteLine("Internet not available, proceed with the download");
                return;
            }

            //So at this point we dont have that file with us locally.. so lets download
            Console.WriteLine("Start Downloading....");
            try
            {
                using (WebClient client = new WebClient())
                {
                    client.DownloadProgressChanged += wc_DownloadProgressChanged; // This works well 
                    client.DownloadFileCompleted += wc_DownloadFileCompleted;
                    client.DownloadFileAsync(new System.Uri(CmsDownLoadSite), Destinationfile);
                }
            }
            catch (WebException we)
            {
                Console.WriteLine(we.ToString());
            }
            Console.ReadLine(); // We dont want the black screen to just disapper from us. so we put a readline so that it will keep displaying all the messsages

        }

        private static void wc_DownloadFileCompleted(object sender, System.ComponentModel.AsyncCompletedEventArgs e)
        {
            if (e.Cancelled)
            {
                Console.WriteLine("The download has been cancelled");
                return;
            }

            if (e.Error != null)
            {
                //I tested the the program 2 times.. each time an error occured.
                //The error message is "An exceptipon occured during a WebClient request.
                Console.WriteLine("An error ocurred while trying to download file");
                Console.WriteLine(e.Error.Message.ToString());
                return;
            }

            // I did not see this on the screen.. ????
            Console.WriteLine("..............File succesfully downloaded......This mesage comes from --  wc_DownloadFileCompleted..........");
        }

        private static void wc_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e)
        {

            if (FileDownLoadPercentage.Value != e.ProgressPercentage.ToString())
            {
                FileDownLoadPercentage.Value = e.ProgressPercentage.ToString();

                //Display File Donwload Percentage ( increments of 10 ) 
                if (Convert.ToInt16(e.ProgressPercentage) % 10 == 0)
                    Console.WriteLine(e.ProgressPercentage.ToString());

                //Show the percentage when it is 99
                if (Convert.ToInt16(e.ProgressPercentage) == 99)
                    Console.WriteLine(e.ProgressPercentage.ToString());
            }


            if (e.BytesReceived == e.TotalBytesToReceive)
            {
                Console.WriteLine("File DownLoad Complete...This message comes from --  wc_DownloadProgressChanged  "); // I did not see this on the screen.. ????
            }
        }
    }
}

Webclient.DownloadFileCompleted事件失败

0 个答案: