FormDownload.cs

// Name:        FormCode.cs
// Description: Dialog box for downloading content
// Author:      Tim Chipman
// Origination: Work performed for BuildingSmart by Constructivity.com LLC.
// Copyright:   (c) 2013 BuildingSmart International Ltd.
// License:     http://www.buildingsmart-tech.org/legal

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Net;
using System.Text;
using System.Windows.Forms;

namespace IfcDoc
{
    public partial class FormDownload : Form
    {
        Exception m_exception;
        string m_localpath;

        public FormDownload()
        {
            InitializeComponent();
        }

        public string Url
        {
            get
            {
                return this.textBoxUrl.Text;
            }
        }

        public string LocalPath
        {
            get
            {
                return this.m_localpath;
            }
        }

        private void buttonOK_Click(object sender, EventArgs e)
        {
            this.textBoxUrl.Enabled = false;
            this.progressBar.Value = 0;
            this.buttonOK.Enabled = false;
            this.errorProvider.Clear();

            // start download to local file
            this.backgroundWorkerDownload.RunWorkerAsync();
        }

        private void backgroundWorkerDownload_DoWork(object sender, DoWorkEventArgs e)
        {
            // connect to server
            this.m_exception = null;
            try
            {
                HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(this.textBoxUrl.Text);
                request.Accept = "text/plain";// "application/step";
                using (WebResponse response = request.GetResponse())
                {                    
                    using (Stream streamWeb = response.GetResponseStream())
                    {                        
                        this.m_localpath = Path.GetTempFileName();
                        this.m_localpath = Path.ChangeExtension(this.m_localpath, ".ifcdoc");
                        using (FileStream streamFile = new FileStream(this.m_localpath, FileMode.CreateNew))
                        {
                            streamFile.SetLength(response.ContentLength);
                            byte[] buffer = new byte[8192];
                            int len = 0;
                            do
                            {
                                len = streamWeb.Read(buffer, 0, buffer.Length);
                                if (len > 0)
                                {
                                    streamFile.Write(buffer, 0, len);
                                    this.backgroundWorkerDownload.ReportProgress((int)(100L * streamFile.Position / streamFile.Length));
                                }
                            } while (len > 0);
                        }
                    }
                }
            }
            catch (Exception x)
            {
                this.m_exception = x;                
            }
        }

        private void backgroundWorkerDownload_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            this.progressBar.Value = e.ProgressPercentage;
        }

        private void backgroundWorkerDownload_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            if (m_exception != null)
            {
                this.textBoxUrl.Enabled = true;
                this.buttonOK.Enabled = true;
                this.errorProvider.SetError(this.labelError, this.m_exception.Message);
            }
            else
            {
                this.DialogResult = DialogResult.OK;
                this.Close();
            }
        }
    }
}