如何使用webclient获取电影大小，而无需下载？ [英] How to use webclient to get a movie size, without download it?

问题描述

如何使用WebClient获取电影大小，无需下载？



如果没有下载实际文件，我无法使用DownloadProgressChanged方法，实际下载过程链接。

我只想查询页面并仅提取数据，而没有实际内容。

谢谢。



我尝试了什么：

How to use WebClient to get a movie size, without download it?

Without downloading the actual file, I can not use the "DownloadProgressChanged" method, which is linked by the actual download process.
I only wish to interrogate the page and extract only the data, without the actual content.
Thanks.

What I have tried:

WebClient wc;
void Download4()
{
    wc = new WebClient();

    Uri uri = new Uri(url);
    wc.DownloadFileAsync(uri, movieName);
    wc.DownloadProgressChanged += new DownloadProgressChangedEventHandler(wc_DownloadProgressChanged);
    wc.DownloadFileCompleted += new AsyncCompletedEventHandler(wc_DownloadFileCompleted);
}

 void wc_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e)
 {
     label1.Text = Website.SizeSuffix(e.BytesReceived) + "/" + Website.SizeSuffix(e.TotalBytesToReceive);


         TotalBytesToReceive = TotalBytesToReceive + e.TotalBytesToReceive;

 }

 void wc_DownloadFileCompleted(object sender, AsyncCompletedEventArgs e)
 {
    label2.Text = TotalBytesToReceive.ToString();
 }

推荐答案

当然你不需要下载整个文件，因为HTTP告诉你整个流将有多大。但要以这种方式解决问题，你不应该使用真正基本的 System.Net.WebClient 。你必须使用 HttpWebRequest ：

WebClient类（System.Net） [ ^ ]，

HttpWebRequest Class（System.Net） [ ^ ]。br />


以下是我的建议：请下载我在过去的答案中提供的HttpDownloaded的完整代码：如何从互联网上下载文件 [ ^ ]。



此下载程序允许继续下载未完全下载的文件，这显然是基于获取网络流的完整大小从一开始就。你会看到如何做到这一点。这是一小段代码，只有一个文件;很容易阅读和理解。



另见我过去的答案：

如何从Asp.net 2.0中的服务器下载文件 [< a href =http://www.codeproject.com/Answers/212311/how-to-download-a-file-from-the-server-in-Asp-net#answer3target =_ blanktitle =新窗口> ^ ]，

FTP：下载文件 [ ^ ]，

如何从另一个站点获取数据 [ ^ ]。

-SA

Of course you don't need to download a whole file, because HTTP tells you how big the whole stream will be. But to solve the problem this way, you should not use really rudimentary System.Net.WebClient. You have to use HttpWebRequest instead:
WebClient Class (System.Net)[^],
HttpWebRequest Class (System.Net)[^].

Here is what I can suggest: please download the full code of my HttpDownloaded I provided in my past answer: how to download a file from internet[^].

This downloader allows to continue downloading of incompletely downloaded file, which apparently is based on getting the full size of a network stream from the very beginning. You will see how to do it. This is a very small piece of code, only one file; quite easy to read and understand.

See also my past answers:
how to download a file from the server in Asp.net 2.0[^],
FTP: Download Files[^],
How to get the data from another site[^].

—SA

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