C # Asynchronous bulk download file

Implementation principle: The use of WebClient for bulk download tasks, simple simulation thunder download effect!

Don't say much nonsense, first look at the disguise effect:

The specific implementation steps are as follows:

1. New Project: Winbatchdownload

2. First build a Windows Form: frmbatchdownload, Load event frmbatchdownload_load

3. Place a button: Btnstartdownload, single event Btnstartdownload_click

4. Place a datagridview:dgvdownload.

5. The specific code is as follows:

Using system;using system.collections.generic;using system.componentmodel;using system.data;using System.Drawing; Using system.text;using System.Windows.Forms; #region namespace using system.threading;using    System.runtime.interopservices;using system.net;using System.Collections, #endregionnamespace winbatchdownload{ Public partial class Frmbatchdownload:form {#region Global member//store download list list<synfileinfo> M_syn        Fileinfolist;            #endregion #region Constructor Public frmbatchdownload () {InitializeComponent ();        M_synfileinfolist = new list<synfileinfo> ();            #endregion #region Form Load event private void Frmbatchdownload_load (object sender, EventArgs e) {            Initializes the DataGridView related attribute Initdatagridview (dgvdownload);            Add DataGridView Related column information addgridviewcolumns (dgvdownload);        New Task Addbatchdownload (); } #endregion #region Add grIdview columns///<summary>///Synchronizing list///</summary> void Addgridviewcolumns (Datagridvi EW DGV) {DGV. Columns.Add (New Datagridviewtextboxcolumn () {datapropertyname = "DocID", Headert            ext = "File id", Visible = false, Name = "DocID"}); DGV. Columns.Add (New Datagridviewtextboxcolumn () {AutoSizeMode = Datagridviewautosizecolumnmode.none                , DataPropertyName = "DocName", HeaderText = "file name", name = "DocName",            Width = 300}); DGV. Columns.Add (New Datagridviewtextboxcolumn () {datapropertyname = "FileSize", Head            Ertext = "Size", Name = "FileSize",}); DGV. Columns.Add (New Datagridviewtextboxcolumn () {datapropertyname = "synspeed", Head ERtext = "Speed", Name = "Synspeed"}); DGV. Columns.Add (New Datagridviewtextboxcolumn () {datapropertyname = "synprogress", H            Eadertext = "Progress", Name = "synprogress"}); DGV. Columns.Add (New Datagridviewtextboxcolumn () {datapropertyname = "Downpath", Head            Ertext = "", Visible = false, Name = "Downpath"}); DGV. Columns.Add (New Datagridviewtextboxcolumn () {datapropertyname = "Savepath", Head            Ertext = "Save Address", Visible = false, Name = "Savepath"}); DGV. Columns.Add (New Datagridviewtextboxcolumn () {datapropertyname = "Async", Headert        ext = "Async", Visible = false, Name = "Async"}); } #endregion #region Add download task and display to list void Addbatchdownload () {//Empty row data dgvDownLoad.Rows.Clear ();            Add a list (build multiple tasks) list<arraylist> arraylistlist = new list<arraylist> (); Arraylistlist.add (New ArrayList () {"0",//File ID "PPTV client. exe",//File name "21.2 MB", File Size "0 kb/s",//download Speed "0%",//Download Progress "http://download.pplive.com/pptvsetup_3.2.            1.0076.exe ",//Remote server" D:\\PPTV client. exe ",//local Save Address true//whether asynchronous});                Arraylistlist.add (New ArrayList () {"1", "PPS client. exe", "14.3 MB", "0 kb/s", "0%", "Http://download.ppstream.com/ppstreamsetup.exe", "D:\\pps            Client. exe ", true});      Arraylistlist.add (New ArrayList () {"2", "Beautiful view client. exe", "4.1 MB",          "0 kb/s", "0%", "Http://kankan.dl.meitu.com/V2/1029/KanKan_kk360Setup.exe",            "D:\\ to see client. exe", true}); foreach (ArrayList ArrayList in arraylistlist) {int rowIndex = DGVDOWNLOAD.ROWS.ADD (arraylist.t                Oarray ());                ARRAYLIST[2] = 0;                Arraylist.add (Dgvdownload.rows[rowindex]);            Remove the row information from the list in the Save list Collection (M_synfileinfolist) M_synfileinfolist.add (New Synfileinfo (Arraylist.toarray ())); }} #endregion #region start the download button standalone event private void Btnstartdownload_click (object sender, Event                Args e) {//Determine if the network connection is normal if (isconnected ()) {//settings are not available                btnstartdownload.enabled = false;                Sets the maximum number of active threads and the number of threads to wait Threadpool.setmaxthreads (3, 3); Determine if there is a task if (m_synfileinfolist.count <= 0) addbaTchdownload (); foreach (Synfileinfo m_synfileinfo in m_synfileinfolist) {//Start download Task S                Tartdownload (M_synfileinfo);            }} else {MessageBox.Show ("network exception!"); }} #endregion #region Check network status//Detect network Status [DllImport ("Wininet.dll")] extern static        BOOL InternetGetConnectedState (out int connectiondescription, int reservedvalue);             <summary>///Detect network Status///</summary> bool IsConnected () {int I = 0;            BOOL state = InternetGetConnectedState (out I, 0);        return state; #endregion #region Download the file using WebClient//<summary>//HTTP to download the remote file and save the local function///&LT            ;/summary> void Startdownload (object o) {synfileinfo m_synfileinfo = (synfileinfo) o; M_synfileinfo.lasttime = DateTime.Now;            Again new to avoid WebClient cannot I/o concurrency WebClient client = new WebClient (); if (M_synfileinfo.async) {//asynchronously downloads the 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>///download progress bar///</summary>//<param name= "Sender" ></param >//<param name= "E" ></param> void Client_downloadprogresschanged (object sender, Downloadpro            Gresschangedeventargs 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"; The corresponding data in Update DataGridView shows the download Progress m_synfileinfo.rowobject.cells["Synprogress".            Value = m_synfileinfo.synprogress; The corresponding data in Update DataGridView shows the download speed (average speed of total progress) m_synfileinfo.rowobject.cells["Synspeed".        Value = M_synfileinfo.synspeed; }///<summary>///Download complete call///</summary>//<param name= "Sender" ></para m>//<param name= "E" ></param> void client_downloadfilecompleted (object sender, Asynccomplet            Edeventargs e) {//to which a file has been downloaded synfileinfo m_synfileinfo = (synfileinfo) e.userstate;            M_synfileinfolist.remove (M_synfileinfo); if (m_synfileinfolist.count <= 0) {//At this time All files are downloaded btnstartdownload.enabled = true; }} #endregion #region need to download the file entity classes class Synfileinfo {public string DocID {g Et 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 initialization of GridView void Initdatagridview (DataGridView dgv) { DGV. AutoGenerateColumns = false;//Whether the column DGV is created automatically. Allowusertoaddrows = false;//Whether to allow rows to be added (default: TRUE) DGV. Allowusertodeleterows = false;//Whether to allow deletion of rows (default: TRUE) DGV. Allowusertoresizecolumns = false;//whether to allow resizing (default: TRUE) DGV. Allowusertoresizerows = false;//Whether to allow row size adjustment (default: TRUE) DGV.            autoSizeColumnsMode = datagridviewautosizecolumnsmode.fill;//column width mode (current fill) (Default: Datagridviewautosizecolumnsmode.none) DGV. BackgroundColor = system.drawing.color.white;//background color (default: ControlDark) DGV. BorderStyle = borderstyle.fixed3d;//Border Style (default: BorderStyle.FixedSingle) DGV. CellbordErstyle = datagridviewcellborderstyle.singlehorizontal;//cell border Style (default: Datagridviewcellborderstyle.single) DGV.            Columnheadersborderstyle = datagridviewheaderborderstyle.none;//list Header style (default: Datagridviewheaderborderstyle.single) DGV. Columnheadersheightsizemode = datagridviewcolumnheadersheightsizemode.disableresizing;//whether to allow column size adjustment ( Default: Datagridviewcolumnheadersheightsizemode.enableresizing) DGV. Columnheadersheight = 30;//List Header height (default:) DGV. MultiSelect = false;//supports multiple selection (default: TRUE) DGV. ReadOnly = true;//is read-only (default: false) DGV. Rowheadersvisible = false;//If the wardrobe is displayed (default: TRUE) DGV. SelectionMode = datagridviewselectionmode.fullrowselect;//Select mode (default: Datagridviewselectionmode.cellselect)} #e Ndregion #region File related Operations classes///<summary>////Documents Related Operations class///</summary> Public            Class Fileoperate {#region The corresponding unit conversion constant 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 Get Fit Size//<summary>//Get fit size///</summary> <param name= "Size" > Byte size </param>//<param name= "Roundcount" > Reserved decimals (bit) </param >//<returns></returns> public static string getautosizestring (double size, int rou                Ndcount) {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}} 

Source: Https://github.com/marblemm/WinBatchDownload

C # Asynchronous bulk download file