我正在尝试制作一个用于从我的网站下载文件的用户界面。该网站包含zip文件，需要将这些文件下载到用户输入的目录中。但是，我无法成功下载文件，它只是从临时文件夹中打开。
代码:
private void webBrowser1_Navigating(object sender, WebBrowserNavigatingEventArgs e)
{
e.Cancel = true;
string filepath = null;
filepath = textBox1.Text;
WebClient client = new WebClient();
client.DownloadFileCompleted += new AsyncCompletedEventHandler(client_DownloadFileCompleted);
client.DownloadFileAsync(e.Url, filepath);
}
Directory.CreateDirectory(C:\dir\dira\dirb); // This code will create all of these directories
这段代码将下载给定的文件到给定的目录中（在前面的代码片段创建后）：
private void install()
{
WebClient webClient = new WebClient(); // Creates a webclient
webClient.DownloadFileCompleted += new AsyncCompletedEventHandler(Completed); // Uses the Event Handler to check whether the download is complete
webClient.DownloadProgressChanged += new DownloadProgressChangedEventHandler(ProgressChanged); // Uses the Event Handler to check for progress made
webClient.DownloadFileAsync(new Uri("http://www.com/newfile.zip"), @"C\newfile.zip"); // Defines the URL and destination directory for the downloaded file
}
因此，使用这两个代码片段，您可以创建所有目录，然后告诉下载器（不提示您将文件下载到该位置）。
如果您不想使用 "WebClient" 或者需要使用 System.Windows.Forms.WebBrowser，例如因为您想先模拟登录，那么您可以使用这个扩展的 WebBrowser。它钩取了 Windows URLMON 库中的 "URLDownloadToFile" 方法，并使用 WebBrowser 的上下文。
信息：http://www.pinvoke.net/default.aspx/urlmon/URLDownloadToFile%20.html
using System;
using System.IO;
using System.Runtime.InteropServices;
using System.Windows.Forms;
namespace dataCoreLib.Net.Webpage
{
public class WebBrowserWithDownloadAbility : WebBrowser
{
/// <summary>
/// The URLMON library contains this function, URLDownloadToFile, which is a way
/// to download files without user prompts. The ExecWB( _SAVEAS ) function always
/// prompts the user, even if _DONTPROMPTUSER parameter is specified, for "internet
/// security reasons". This function gets around those reasons.
/// </summary>
/// <param name="callerPointer">Pointer to caller object (AX).</param>
/// <param name="url">String of the URL.</param>
/// <param name="filePathWithName">String of the destination filename/path.</param>
/// <param name="reserved">[reserved].</param>
/// <param name="callBack">A callback function to monitor progress or abort.</param>
/// <returns>0 for okay.</returns>
/// source: http://www.pinvoke.net/default.aspx/urlmon/URLDownloadToFile%20.html
[DllImport("urlmon.dll", CharSet = CharSet.Auto, SetLastError = true)]
static extern Int32 URLDownloadToFile(
[MarshalAs(UnmanagedType.IUnknown)] object callerPointer,
[MarshalAs(UnmanagedType.LPWStr)] string url,
[MarshalAs(UnmanagedType.LPWStr)] string filePathWithName,
Int32 reserved,
IntPtr callBack);
/// <summary>
/// Download a file from the webpage and save it to the destination without promting the user
/// </summary>
/// <param name="url">the url with the file</param>
/// <param name="destinationFullPathWithName">the absolut full path with the filename as destination</param>
/// <returns></returns>
public FileInfo DownloadFile(string url, string destinationFullPathWithName)
{
URLDownloadToFile(null, url, destinationFullPathWithName, 0, IntPtr.Zero);
return new FileInfo(destinationFullPathWithName);
}
}
}
private void webBrowser1_Navigating(object sender, WebBrowserNavigatingEventArgs e)
{
e.Cancel = true;
WebClient client = new WebClient();
client.DownloadDataCompleted += new DownloadDataCompletedEventHandler(client_DownloadDataCompleted);
client.DownloadDataAsync(e.Url);
}
void client_DownloadDataCompleted(object sender, DownloadDataCompletedEventArgs e)
{
string filepath = textBox1.Text;
File.WriteAllBytes(filepath, e.Result);
MessageBox.Show("File downloaded");
}
你的解决方案基本可行。有几个要点需要考虑以保持简单：
仅针对您知道将发生下载的特定URL取消默认导航，否则用户将无法导航到任何地方。这意味着您不应更改网站下载URL。
DownloadFileAsync 不知道服务器在 Content-Disposition 标头中报告的名称，因此您必须指定一个名称或者从原始URL计算一个名称（如果可能）。您不能只指定文件夹并期望自动检索文件名。
您必须从 DownloadCompleted 回调处理下载服务器错误，因为 Web 浏览器控件不再为您执行此操作。
代码示例，将下载到 textBox1 指定的目录中，但使用随机文件名，并且没有任何其他错误处理：
private void webBrowser1_Navigating(object sender, WebBrowserNavigatingEventArgs e) {
/* change this to match your URL. For example, if the URL always is something like "getfile.php?file=xxx", try e.Url.ToString().Contains("getfile.php?") */
if (e.Url.ToString().EndsWith(".zip")) {
e.Cancel = true;
string filePath = Path.Combine(textBox1.Text, Path.GetRandomFileName());
var client = new WebClient();
client.DownloadFileCompleted += client_DownloadFileCompleted;
client.DownloadFileAsync(e.Url, filePath);
}
}
private void client_DownloadFileCompleted(object sender, AsyncCompletedEventArgs e) {
MessageBox.Show("File downloaded");
}
这个解决方案应该是可行的，但很容易被破坏。尝试考虑一些列出可下载文件的网络服务，并为其制作自定义UI。这样会更简单，您将控制整个过程。
string filename = Path.GetFileName(e.Url.LocalPath)。 - rotman请查看http://www.csharp-examples.net/download-files/和WebClient的MSDN文档http://msdn.microsoft.com/en-us/library/system.net.webclient.aspx
我的建议是尝试同步下载，因为它更直接。在尝试此操作时，您可能会得到有关WebClient参数错误或文件格式不正确的想法。
这是一个代码示例...
private void btnDownload_Click(object sender, EventArgs e)
{
string filepath = textBox1.Text;
WebClient webClient = new WebClient();
webClient.DownloadFileCompleted += new AsyncCompletedEventHandler(Completed);
webClient.DownloadProgressChanged += new DownloadProgressChangedEventHandler(ProgressChanged);
webClient.DownloadFileAsync(new Uri("http://mysite.com/myfile.txt"), filepath);
}
private void ProgressChanged(object sender, DownloadProgressChangedEventArgs e)
{
progressBar.Value = e.ProgressPercentage;
}
private void Completed(object sender, AsyncCompletedEventArgs e)
{
MessageBox.Show("Download completed!");
}
using System;
using System.Diagnostics;
using System.ComponentModel;
namespace MyProcessSample
{
class MyProcess
{
public static void Main()
{
Process myProcess = new Process();
myProcess.Start("chrome.exe","http://www.com/newfile.zip");
}
}
}
WebBrowser类）？也许你应该明确地说出来。虽然从你的方法名称中可以看出，但我一开始并没有注意到这一点。 - CodesInChaos