C#异步批量下载文件
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：
using System;
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
}
}
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
