C#异步批量下载文件 – liger_zql – 博客园

实现原理:采用WebClient进行批量下载任务,简单的模拟迅雷下载效果!

废话不多说,先看掩饰效果:

具体实现步骤如下:

1.新建项目:WinBatchDownload

2.先建一个Windows窗体:FrmBatchDownload,加载事件FrmBatchDownload_Load

3.放置一个Button按钮:btnStartDownLoad,单机事件btnStartDownLoad_Click

4.放置一个DataGridView:dgvDownLoad.

5.具体代码如下:

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<span style="color: #0000ff;">using</span><span style="color: #000000;"> System;</span>

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

#region 命名空间

using System.Threading;

using System.Runtime.InteropServices;

using System.Net;

using System.Collections;

#endregion

namespace WinBatchDownload

{

public partial class FrmBatchDownload : Form

{

#region 全局成员

//存放下载列表

List<SynFileInfo> m_SynFileInfoList;

#endregion

#region 构造函数

public FrmBatchDownload()

{

InitializeComponent();

m_SynFileInfoList = new List<SynFileInfo>();

}

#endregion

#region 窗体加载事件

private void FrmBatchDownload_Load(object sender, EventArgs e)

{

//初始化DataGridView相关属性

InitDataGridView(dgvDownLoad);

//添加DataGridView相关列信息

AddGridViewColumns(dgvDownLoad);

//新建任务

AddBatchDownload();

}

#endregion

#region 添加GridView列

/// <summary>

/// 正在同步列表

/// </summary>

void AddGridViewColumns(DataGridView dgv)

{

dgv.Columns.Add(new DataGridViewTextBoxColumn()

{

DataPropertyName = DocID,

HeaderText = 文件ID,

Visible = false,

Name = DocID

});

dgv.Columns.Add(new DataGridViewTextBoxColumn()

{

AutoSizeMode = DataGridViewAutoSizeColumnMode.None,

DataPropertyName = DocName,

HeaderText = 文件名,

Name = DocName,

Width = 300

});

dgv.Columns.Add(new DataGridViewTextBoxColumn()

{

DataPropertyName = FileSize,

HeaderText = 大小,

Name = FileSize,

});

dgv.Columns.Add(new DataGridViewTextBoxColumn()

{

DataPropertyName = SynSpeed,

HeaderText = 速度,

Name = SynSpeed

});

dgv.Columns.Add(new DataGridViewTextBoxColumn()

{

DataPropertyName = SynProgress,

HeaderText = 进度,

Name = SynProgress

});

dgv.Columns.Add(new DataGridViewTextBoxColumn()

{

DataPropertyName = DownPath,

HeaderText = 下载地址,

Visible = false,

Name = DownPath

});

dgv.Columns.Add(new DataGridViewTextBoxColumn()

{

DataPropertyName = SavePath,

HeaderText = 保存地址,

Visible = false,

Name = SavePath

});

dgv.Columns.Add(new DataGridViewTextBoxColumn()

{

DataPropertyName = Async,

HeaderText = 是否异步,

Visible = false,

Name = Async

});

}

#endregion

#region 添加下载任务并显示到列表中

void AddBatchDownload()

{

//清空行数据

dgvDownLoad.Rows.Clear();

//添加列表(建立多个任务)

List<ArrayList> arrayListList = new List<ArrayList>();

arrayListList.Add(new ArrayList(){

0,//文件id

PPTV客户端.exe,//文件名称

21.2 MB,//文件大小

0 KB/S,//下载速度

0%,//下载进度

http://download.pplive.com/pptvsetup_3.2.1.0076.exe,//远程服务器下载地址

D:\\PPTV客户端.exe,//本地保存地址

true//是否异步

});

arrayListList.Add(new ArrayList(){

1,

PPS客户端.exe,

14.3 MB,

0 KB/S,

0%,

http://download.ppstream.com/ppstreamsetup.exe,

D:\\PPS客户端.exe,

true

});

arrayListList.Add(new ArrayList(){

2,

美图看看客户端.exe,

4.1 MB,

0 KB/S,

0%,

http://kankan.dl.meitu.com/V2/1029/KanKan_kk360Setup.exe,

D:\\美图看看客户端.exe,

true

});

foreach (ArrayList arrayList in arrayListList)

{

int rowIndex = dgvDownLoad.Rows.Add(arrayList.ToArray());

arrayList[2] = 0;

arrayList.Add(dgvDownLoad.Rows[rowIndex]);

//取出列表中的行信息保存列表集合(m_SynFileInfoList)中

m_SynFileInfoList.Add(new SynFileInfo(arrayList.ToArray()));

}

}

#endregion

#region 开始下载按钮单机事件

private void btnStartDownLoad_Click(object sender, EventArgs e)

{

//判断网络连接是否正常

if (isConnected())

{

//设置不可用

btnStartDownLoad.Enabled = false;

//设置最大活动线程数以及可等待线程数

ThreadPool.SetMaxThreads(3, 3);

//判断是否还存在任务

if (m_SynFileInfoList.Count <= 0) AddBatchDownload();

foreach (SynFileInfo m_SynFileInfo in m_SynFileInfoList)

{

//启动下载任务

StartDownLoad(m_SynFileInfo);

}

}

else

{

MessageBox.Show(网络异常!);

}

}

#endregion

#region 检查网络状态

//检测网络状态

[DllImport(wininet.dll)]

extern static bool InternetGetConnectedState(out int connectionDescription, int reservedValue);

/// <summary>

/// 检测网络状态

/// </summary>

bool isConnected()

{

int I = 0;

bool state = InternetGetConnectedState(out I, 0);

return state;

}

#endregion

#region 使用WebClient下载文件

/// <summary>

/// HTTP下载远程文件并保存本地的函数

/// </summary>

void StartDownLoad(object o)

{

SynFileInfo m_SynFileInfo = (SynFileInfo)o;

m_SynFileInfo.LastTime = DateTime.Now;

//再次new 避免WebClient不能I/O并发

WebClient client = new WebClient();

if (m_SynFileInfo.Async)

{

//异步下载

client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(client_DownloadProgressChanged);

client.DownloadFileCompleted += new AsyncCompletedEventHandler(client_DownloadFileCompleted);

client.DownloadFileAsync(new Uri(m_SynFileInfo.DownPath), m_SynFileInfo.SavePath, m_SynFileInfo);

}

else client.DownloadFile(new Uri(m_SynFileInfo.DownPath), m_SynFileInfo.SavePath);

}

/// <summary>

/// 下载进度条

/// </summary>

/// <param name=”sender”></param>

/// <param name=”e”></param>

void client_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e)

{

SynFileInfo m_SynFileInfo = (SynFileInfo)e.UserState;

m_SynFileInfo.SynProgress = e.ProgressPercentage + %;

double secondCount = (DateTime.Now – m_SynFileInfo.LastTime).TotalSeconds;

m_SynFileInfo.SynSpeed = FileOperate.GetAutoSizeString(Convert.ToDouble(e.BytesReceived / secondCount), 2) + /s;

//更新DataGridView中相应数据显示下载进度

m_SynFileInfo.RowObject.Cells[SynProgress].Value = m_SynFileInfo.SynProgress;

//更新DataGridView中相应数据显示下载速度(总进度的平均速度)

m_SynFileInfo.RowObject.Cells[SynSpeed].Value = m_SynFileInfo.SynSpeed;

}

/// <summary>

/// 下载完成调用

/// </summary>

/// <param name=”sender”></param>

/// <param name=”e”></param>

void client_DownloadFileCompleted(object sender, AsyncCompletedEventArgs e)

{

//到此则一个文件下载完毕

SynFileInfo m_SynFileInfo = (SynFileInfo)e.UserState;

m_SynFileInfoList.Remove(m_SynFileInfo);

if (m_SynFileInfoList.Count <= 0)

{

//此时所有文件下载完毕

btnStartDownLoad.Enabled = true;

}

}

#endregion

#region 需要下载文件实体类

class SynFileInfo

{

public string DocID { get; set; }

public string DocName { get; set; }

public long FileSize { get; set; }

public string SynSpeed { get; set; }

public string SynProgress { get; set; }

public string DownPath { get; set; }

public string SavePath { get; set; }

public DataGridViewRow RowObject { get; set; }

public bool Async { get; set; }

public DateTime LastTime { get; set; }

public SynFileInfo(object[] objectArr)

{

int i = 0;

DocID = objectArr[i].ToString(); i++;

DocName = objectArr[i].ToString(); i++;

FileSize = Convert.ToInt64(objectArr[i]); i++;

SynSpeed = objectArr[i].ToString(); i++;

SynProgress = objectArr[i].ToString(); i++;

DownPath = objectArr[i].ToString(); i++;

SavePath = objectArr[i].ToString(); i++;

Async = Convert.ToBoolean(objectArr[i]); i++;

RowObject = (DataGridViewRow)objectArr[i];

}

}

#endregion

#region 初始化GridView

void InitDataGridView(DataGridView dgv)

{

dgv.AutoGenerateColumns = false;//是否自动创建列

dgv.AllowUserToAddRows = false;//是否允许添加行(默认:true)

dgv.AllowUserToDeleteRows = false;//是否允许删除行(默认:true)

dgv.AllowUserToResizeColumns = false;//是否允许调整大小(默认:true)

dgv.AllowUserToResizeRows = false;//是否允许调整行大小(默认:true)

dgv.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.Fill;//列宽模式(当前填充)(默认:DataGridViewAutoSizeColumnsMode.None)

dgv.BackgroundColor = System.Drawing.Color.White;//背景色(默认:ControlDark)

dgv.BorderStyle = BorderStyle.Fixed3D;//边框样式(默认:BorderStyle.FixedSingle)

dgv.CellBorderStyle = DataGridViewCellBorderStyle.SingleHorizontal;//单元格边框样式(默认:DataGridViewCellBorderStyle.Single)

dgv.ColumnHeadersBorderStyle = DataGridViewHeaderBorderStyle.None;//列表头样式(默认:DataGridViewHeaderBorderStyle.Single)

dgv.ColumnHeadersHeightSizeMode = DataGridViewColumnHeadersHeightSizeMode.DisableResizing;//是否允许调整列大小(默认:DataGridViewColumnHeadersHeightSizeMode.EnableResizing)

dgv.ColumnHeadersHeight = 30;//列表头高度(默认:20)

dgv.MultiSelect = false;//是否支持多选(默认:true)

dgv.ReadOnly = true;//是否只读(默认:false)

dgv.RowHeadersVisible = false;//行头是否显示(默认:true)

dgv.SelectionMode = DataGridViewSelectionMode.FullRowSelect;//选择模式(默认:DataGridViewSelectionMode.CellSelect)

}

#endregion

#region 文件相关操作类分

/// <summary>

/// 文件有关的操作类

/// </summary>

public class FileOperate

{

#region 相应单位转换常量

private const double KBCount = 1024;

private const double MBCount = KBCount * 1024;

private const double GBCount = MBCount * 1024;

private const double TBCount = GBCount * 1024;

#endregion

#region 获取适应大小

/// <summary>

/// 得到适应大小

/// </summary>

/// <param name=”size”>字节大小</param>

/// <param name=”roundCount”>保留小数(位)</param>

/// <returns></returns>

public static string GetAutoSizeString(double size, int roundCount)

{

if (KBCount > size) return Math.Round(size, roundCount) + B;

else if (MBCount > size) return Math.Round(size / KBCount, roundCount) + KB;

else if (GBCount > size) return Math.Round(size / MBCount, roundCount) + MB;

else if (TBCount > size) return Math.Round(size / GBCount, roundCount) + GB;

else return Math.Round(size / TBCount, roundCount) + TB;

}

#endregion

}

#endregion

}

}

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到此批量下载功能实现完毕,上面写的代码比较灵活,需要的朋友可以根据自己的项目修改相关内容。

最后附上源码:WinBatchDownload.zip

来源URL:http://www.cnblogs.com/zengqinglei/archive/2012/11/09/2762154.html