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 下载示例

{

    public delegate void form1ContentControl(bool isFinish);

    public partial class Form2 : Form

    {

        public Form2(string _sourceFile,string _destFile)

        {

            InitializeComponent();

            sourceFile = _sourceFile;

            destFile = _destFile;

        }

        public string sourceFile;

        public string destFile;

        public event form1ContentControl contentControl;

        private void Form2_Load(object sender, EventArgs e)

        {

            label1.Text = String.Format("[{0}]下载中...",Path.GetFileName(sourceFile));

            fileDownloading();

        }

        private void button1_Click(object sender, EventArgs e)

        {

            if (button1.Text == "取消")

            {

                this.Close();

            }

            else

            {

                contentControl(true);

                this.Close();

            }

        }

        private void fileDownloading()

        {

            try

            {

                WebClient client = new WebClient();

                //进行异变下载

                client.DownloadFileAsync(new Uri(sourceFile), destFile);

                //绑定进度改变时的事件

                client.DownloadProgressChanged += client_DownloadProgressChanged;

                //绑定完成时事件

                client.DownloadFileCompleted += client_DownloadFileCompleted;

            }

            catch (WebException we)

            {

                MessageBox.Show(we.Message);

            }

            catch (Exception ex)

            {

                MessageBox.Show(ex.Message);

            }

        }

        /// <summary>

        /// 事件:WEBCIENT下载进度改变时触发的回调事件

        /// </summary>

        /// <param name="sender"></param>

        /// <param name="e"></param>

        void client_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e)

        {

            Action<DownloadProgressChangedEventArgs> onCompleted = progressChanging;

            onCompleted.Invoke(e);

        }

        /// <summary>

        /// 事件：WEBCLIENT下载完成时的回调事件

        /// </summary>

        /// <param name="sender"></param>

        /// <param name="e"></param>

        void client_DownloadFileCompleted(object sender, AsyncCompletedEventArgs e)

        {

            Action<AsyncCompletedEventArgs> onCompleted = progressCompleted;

            onCompleted.Invoke(e);

        }

        /// <summary>

        /// 文件下载进度改变时触发

        /// </summary>

        /// <param name="de"></param>

        private void progressChanging(DownloadProgressChangedEventArgs de)

        {

            progressBar1.Value = de.ProgressPercentage;

            linkLabel1.Text = String.Format("{0}%",de.ProgressPercentage);

            linkLabel2.Text = String.Format("{0}M/{1}M",Math.Round((double)de.BytesReceived/1024/1024,2),Math.Round((double)de.TotalBytesToReceive/1024/1024,2));

        }

        /// <summary>

        /// 当文件下载完成时触发

        /// </summary>

        /// <param name="de"></param>

        private void progressCompleted(AsyncCompletedEventArgs de)

        {

            label1.Text = String.Format("[{0}]下载已经完成！", Path.GetFileName(sourceFile));

            button1.Text = "完成";

        }

    }

}