用C＃如何下载文件？

Question

用c＃如何下载EXE,DLL,ZIP等类型的文件？PS:最好能有例子～

Answer 1

下载1. C#: 
/// <summary>
/// 文件下载
/// </summary>
/// <param name="FullFileName"></param>
private void FileDownload(string FullFileName)
{
FileInfo DownloadFile = new FileInfo(FullFileName); 
Response.Clear();
Response.ClearHeaders();
Response.Buffer=false;
Response.ContentType="application/octet-stream";
Response.AppendHeader("Content-Disposition","attachment;filename=" +HttpUtility.UrlEncode(DownloadFile.FullName,System.Text.Encoding.UTF8));
Response.AppendHeader("Content-Length",DownloadFile.Length.ToString());
Response.WriteFile(DownloadFile.FullName);
Response.Flush();
Response.End();
}
2. vb.net
Public Sub WriteDLWindow(ByVal strFileName As String, ByVal page As System.Web.UI.Page)
        Try
           If File.Exists(page.MapPath(strFileName)) Then
               Dim TargetFile As FileInfo = New FileInfo(page.MapPath(strFileName))
               '清除缓冲区流中的所有内容输出.
               page.Response.Clear()
               '向输出流添加HTTP头 [指定下载/保存 对话框的文件名]
               page.Response.AppendHeader("Content-Disposition", "attachment; filename=" + page.Server.UrlEncode(TargetFile.Name))

'繁体格式
                'page.Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(strFileName, System.Text.Encoding.UTF8))                '向输出流添加HTTP头 [指定文件的长度,这样下载文件就会显示正确的进度
                page.Response.AppendHeader("Content-Length", TargetFile.Length.ToString())
                '表明输出的HTTP为流[stream],因此客户端只能下载.
                page.Response.ContentType = "application/octet-stream"
                '发送文件流到客户端.
                page.Response.WriteFile(TargetFile.FullName)
                '停止执行当前页
                page.Response.End()
            End If
        Catch ex As Exception
            Throw ex
        End Try
    End Sub

Answer 2

设置保存文件格式(example: *.xls):
Response.ContentType = "application/ms-excel";

Answer 3

这个好象是ASP的下载。
有没有WinForm的下载方法？

Answer 4

直接链接到文件的URL，打开不就下载了？为什么要这么复杂？

Answer 5

同意zjmotion() ( )只要实体在硬盘上,而数据库中保护了各个实体文件的路径,只要输出这个路径就行了,不是吗???

Answer 6

1.用WebRequest发送请求2.得到数据流：WebResponse.GetResponse().GetResponseStream()3.将主体写入文件中

Answer 7

winform 看这个System.Net.WebClient

Answer 8

我对C#.NET不是很熟悉，刚刚接触，不知道具体有哪些控件可用。
如果是ASP.NET，那么就简单了，直接Response.Redirect("http://文件的路径")就可以下载。
如果是WinForm程序，那就找个可以引用地址的控件，WebBrower？这个可以，只要
axWebBrowser1.Navigate("http://文件路径")
就可以开始下载，当然，仅仅为了引用一个地址而动用WebBrower好像有欠妥当，但我真的不知道有没有其他控件可以实现，实在想不到就这样用着吧。呵

Answer 9

能不能给个WinForm下载.exe,.dll,.zip的例子啊～
谢谢！～

Answer 10

自己改一下： private void DownLoadFile()
        {
            try
            {
                WebClient client = new WebClient();                if (!Directory.Exists(Application.StartupPath + @"\update"))
                {
                    Directory.CreateDirectory(Application.StartupPath + @"\update");
                }
                for (int i = 0; i <= this.listView1.Items.Count - 1; i++)
                {
                    string fileName = this.listView1.Items[i].SubItems[0].Text;
                    string url = @"http://172.16.120.155/update/UpdateFile/" + fileName;
                    string file = Application.StartupPath + "\\update\\" + fileName;
                    this.label2.Text = "正在下载：" + fileName;                    Stream myStream = client.OpenRead(url);
                    byte[] bBuffer = new byte[10240];
                    int nRealCount = 0;
                    DateTime dtStart=DateTime.Now ;
                    TimeSpan ts;
                    int lenth = Convert.ToInt32(this.listView1.Items[i].SubItems[1].Text.ToString());
                    int cur = 0;
                    progressBar1.Value = 0;
                    FileStream fs = new FileStream(file, FileMode.OpenOrCreate, FileAccess.Write);
                    //do
                    //{                       
                    //    dtStart = DateTime.Now;
                    //    nRealCount = myStream.Read(bBuffer, 0, bBuffer.Length);
                    //    if (nRealCount > 0)
                    //    {
                    //        fs.Write(bBuffer, 0, nRealCount);
                    //    }
                    //    ts = DateTime.Now - dtStart;
                    //    cur = cur + nRealCount;
                    //    double pe = cur;
                    //    pe = pe * 100 / lenth;
                    //    int va = Convert.ToInt32(pe);
                    //    progressBar1.Value = va;                      
                    //    this.label2.Text = "正在下载：" + fileName + "   " + cur / 1024 + " KB/" + lenth / 1024 + " KB";
                    //    MessageBox.Show("" + ts.Milliseconds + "  " + ts.TotalMilliseconds);
                    //    // this.label2.Text = "正在下载：" + fileName + "   " + cur / 1024 + " KB/" + lenth / 1024 + " KB"+"  下载速度:"+((double )nRealCount /(int)(ts.TotalMilliseconds/1000)) +" kb/s";
                    //    // 计算流量可以用 nRealCount / ts.Seconds来进行估算
                    //}
                    int value=0;
                    int counter = 1;
                    do
                    {
                        if (counter % 10 == 0)
                        {
                            ts = DateTime.Now - dtStart;                            int perSecondsValue = (int)((double)value / (ts.TotalMilliseconds / 1000)) / 1024;                                                        this.label3.Text = "速度：" +perSecondsValue +" k/s";
                            dtStart = DateTime.Now;
                            value = 0;
                        }                      
                       
                        nRealCount = myStream.Read(bBuffer, 0, bBuffer.Length);
                        if (nRealCount > 0)
                        {
                            fs.Write(bBuffer, 0, nRealCount);
                        }
                        cur = cur + nRealCount;
                        double pe = cur;
                        pe = pe * 100 / lenth;
                        int va = Convert.ToInt32(pe);
                        progressBar1.Value = va;
                        
                        this.label2.Text = "正在下载：" + fileName + "   " + cur / 1024 + " KB/" + lenth / 1024 + " KB";                                  
                        
                        value += nRealCount;
                        counter++;
                    }
                    while (nRealCount > 0);
                    fs.Close();                    
                    // client.DownloadFile(url, file);
                    this.listView1.Items[i].SubItems.Add("已下载");
                }                this.progressBar1.Visible = false;
                this.label3.Visible = false;
                this.label2.Text = "正在更新文件,请稍后...";
                string[] fileDir = Directory.GetFileSystemEntries(Application.StartupPath + @"\update");                foreach (string str in fileDir)
                {
                    int pos = str.LastIndexOf(@"\");
                    string FileName = str.Substring(pos);
                    string FilePath = Application.StartupPath + FileName;
                    File.Copy(str, FilePath, true);
                }                this.label2.Text = "程序更新已完成!";                this.label1.Text = this.finish;
                this.btnNext.Enabled = false;
                this.listView1.Visible = false;
                this.btnExit.Text = "完成(&F)";
                step++;
            }
            catch (Exception errMsg)
            {
                MessageBox.Show(errMsg.Message);
            }
        }

Answer 11

qyfjl(Try to improve my skills.) 能不能吧你发的那个完整的例子给我啊～
谢谢～

Answer 12

如果不要进度条。(new WebClient()).DownloadFile("http://123.com/love.zip", "c:\love.zip");就可以下载loave.zip。同理可以下载别的东西。不过，需要进度条的话可以在CodeProject上面找到很多。

Answer 13

那能不能讲讲ListView在这里起到的功能。比如int lenth = Convert.ToInt32(this.listView1.Items[i].SubItems[1].Text.ToString()); 什么意思？

Answer 14

楼主做的是b/s还是c/s
要是c/s我这里倒是有一个读写文件的类