delphi idftp idhttp 多線程多進度條

時間 2019-11-11

標籤 delphi idftp idhttp 多線程進度欄目 Delphi 简体版

原文原文鏈接

idftp 上傳數據庫

多個文件同時上傳，支持斷點續傳，多進度條。服務器

起初用API作，發現對API瞭解太少，便改用線程類來處理，代碼以下ide

TThread1 = class(TThread)
private
   fCount, tstart, tlast: integer;
   tURL, tFile, temFileName,temLocalFile: string;
   tResume: Boolean;
   tStream: TFileStream;
   temFtp: TIdFTP;
   sFileName: string;
   pb: TProgressBar;
   bstate:Integer; //1,表示準備上傳，2表示正在上傳，3表示上傳完成，4表示上傳失敗函數

protected
   procedure Execute; override;
public
   constructor create1(aURL, aFile, fileName,localfile: string; bResume: Boolean; Count,
     start, last: integer);
   procedure DownLodeFile(); //上傳文件
// function SetProgressInListView(lvw: TListView): Boolean; //在listview中動態建立進度條
   procedure StateChange;       //上傳狀態改變
   procedure FtpUp;
end;線程

建立線程以前把進度條動態建立好，給進度條的Tag屬性賦個惟一值，orm

for i:=0 to iCount-1 do
begin
    SetProgressInListView(ListView1,i,1,10,3);  //   建立進度條
    localfile:=ListView1.Items.Item[i].Caption;
    MyThread[i+1] := TThread1.create1('', '', '',localfile, false,i,2,1);
end;同步

constructor TThread1.create1(aURL, aFile, fileName,localfile: string; bResume: Boolean;
Count, start, last: integer);
var
   i:Integer;
begin
inherited create(true);     //設置爲true 主要是爲了調用resume 即建立線程時先不執行，調用thread1.resume執行線程。
freeonterminate:=true;
tURL := aURL;
tFile := aFile;
fCount := Count;
tResume := bResume;
tstart := start;
tlast := last;
temFileName := fileName;
temLocalFile:=localfile;
for i:=0 to Form1.ComponentCount-1 do
begin                                                       //將建好的進度條與線程先對應
    if Form1.Components[i] is TProgressBar then
      if Form1.Components[i].Tag=fcount then
      begin
        pb:=TProgressBar(Form1.Components[i]);
      end;
   end;
end;string

將線程與進度條相對應，線程中的變量最好在線程類中定義，每一個線程都有一塊空間存儲變量的值。上代碼中it

inherited create(true); 設爲true ,因此須要調用TThread.resume來啓動線程io

while j <= iCount do
     begin
       MyThread[j].Resume; //喚醒線程
       j := j + 1;

end;

線程執行函數：執行一次線程，動態建立一個IDFTP控件，將本地文件存成一個流，若是大於1M，則分段截取傳送。

procedure TThread1.DownLodeFile();
const
SEND_BUFFER=1048576;// 一次提交1M的東西
var
AFileStream: TFileStream;
AsFileStream: TMemoryStream;
begin
bstate:=1;
Synchronize(StateChange);
try
    temFtp := TIdFTP.Create(nil);
    temFtp.Host:=Form1.IPEdit.Text;
    temFtp.Username:=Form1.NameEdit.Text;
    temFtp.Password:=Form1.PwdEdit.Text;
    temFtp.Port:=StrToInt(Form1.PortEdit.Text);
    temFtp.Connect;
    temFtp.onWorkBegin := Form1.IdFTP1WorkBegin;
    temFtp.onwork := Form1.IdFTP1work;
    sFileName := ExtractFileName(temLocalFile);
    AFileStream := TFileStream.Create(temLocalFile, fmOpenRead);
//   temFtp.ChangeDir('LoacalUser'); //改變服務器端目錄
    try
// 獲取斷點
      AFileStream.Seek(temFtp.Size(sFileName), soFromBeginning);
// 開始斷點續傳
      AsFileStream:= TMemoryStream.Create;
      pb.Max:=AFileStream.Size;       //進度條賦值
      pb.min:=0;
      bstate:=2;
      Synchronize(StateChange);
      try
        while (AFileStream.Position < AFileStream.Size) do
        begin
          sleep(300);       //等待時間太長
          AsFileStream.Clear;
          AsFileStream.CopyFrom(AFileStream, Min(SEND_BUFFER, AFileStream.Size - AFileStream.Position));
      // AsFileStream.CopyFrom(AFileStream,AFileStream.Size - AFileStream.Position);
          AsFileStream.Position:=0;
          temFtp.Put(AsFileStream, sFileName, true);
          pb.Position:=AFileStream.Position;

        end;
          pb.Position:=AFileStream.Size;
          bstate:=3;
          Synchronize(StateChange);
          AsFileStream.Free;
          AFileStream.free;
      except
        bstate:=4;
        Synchronize(StateChange);
        AsFileStream.Free;
        AFileStream.free;
        raise;
      end;
// 判斷是否上傳完畢
   { if AFileStream.Position = AFileStream.Size then
       ShowMessage('上傳完畢!')
      else
        ShowMessage('下次記得繼續續傳~');
      synchronize(StateChange(true));
      AFileStream.Free;
      }