C# 带进度条的文件下载

private long fileLength;

private long downLength;//已经下载文件大小，外面想用就改成公共属性 

private static bool stopDown;

public HttpDownLoad()

{

    fileLength = 0;

    downLength = 0;

    stopDown = false;

    // 

    //   TODO:   在此处添加构造函数逻辑 

    // 

}

 

///   <summary> 

///   文件下载 

///   </summary> 

///   <param   name= "url "> 连接 </param> 

///   <param   name= "fileName "> 本地保存文件名 </param> 

///   <param   name= "progressBar "> 进度条 </param> 

public void httpDownFile(string url, string fileName, ProgressBar progressBar)

{

    Label lable = new Label();

    httpDownFile(url, fileName, progressBar, lable);

    lable.Dispose();

}

 

///   <summary> 

///   文件下载 

///   </summary> 

///   <param   name= "url "> 连接 </param> 

///   <param   name= "fileName "> 本地保存文件名 </param> 

///   <param   name= "progressBar "> 进度条 </param> 

///   <param   name= "label "> 返回已经下载的百分比 </param> 

public string httpDownFile(string url, string fileName, ProgressBar progressBar, Label label)

{

    string strState = "No";

    stopDown = false;

    Stream str = null, fs = null;

    try

    {

        //获取下载文件长度 

        fileLength = getDownLength(url);

        downLength = 0;

        if (fileLength > 0)

        {

            WebClient DownFile = new WebClient();

            str = DownFile.OpenRead(url);

            //判断并建立文件 

            if (createFile(fileName))

            {

                byte[] mbyte = new byte[1024];

                int readL = str.Read(mbyte, 0, 1024);

                fs = new FileStream(fileName, FileMode.OpenOrCreate, FileAccess.Write);

                //读取流 

                while (readL != 0)

                {

                    if (stopDown)

                        break;

                    downLength += readL;//已经下载大小 

                    fs.Write(mbyte, 0, readL);//写文件 

                    readL = str.Read(mbyte, 0, 1024);//读流 

                    progressBar.Value = (int)(downLength * 100 / fileLength);

                    label.Text = progressBar.Value.ToString() + "% ";

                    Application.DoEvents();

                    strState = "OK";

                }

                str.Close();

                fs.Close();

            }

        }

    }

    catch (Exception)

    {

        if (str != null)

            str.Close();

        if (fs != null)

            fs.Close();

    }

    return strState;

}

 

///   <summary> 

///   文件下载 

///   </summary> 

///   <param   name= "url "> 连接 </param> 

///   <param   name= "fileName "> 本地保存文件名 </param> 

public void httpDownFile(string url, string fileName)

{

    try

    {

        WebClient DownFile = new WebClient();

        DownFile.DownloadFile(url, fileName);

    }

    catch (Exception)

    {

        //MessageBox.Show(ex.Message);

    }

}

 

///   <summary> 

///   获取下载文件大小 

///   </summary> 

///   <param   name= "url "> 连接 </param> 

///   <returns> 文件长度 </returns> 

private long getDownLength(string url)

{

    try

    {

        WebRequest wrq = WebRequest.Create(url);

        WebResponse wrp = (WebResponse)wrq.GetResponse();

        wrp.Close();

        return wrp.ContentLength;

    }

    catch (Exception)

    {

        //MessageBox.Show(ex.Message);

        return 0;

    }

}

 

///   <summary> 

///   建立文件(文件如已经存在，删除重建) 

///   </summary> 

///   <param   name= "fileName "> 文件全名(包括保存目录) </param> 

///   <returns> </returns> 

private bool createFile(string fileName)

{

    try

    {

        if (File.Exists(fileName))

        {

            File.Delete(fileName);

        }

        Stream s = File.Create(fileName);

        s.Close();

        return true;

    }

    catch (Exception)

    {

        //MessageBox.Show(ex.Message);

        return false;

    }

}

 

public void downClose()

{

    stopDown = true;
}