idhttp来下载时进度条的问题

Question

程序是由idhttp来下载东西,原来的程序是用idhttp控件,
现在我想把原来的代码改成多线程的(大致代码如下):
procedure TThreadHttp.Execute;
var
  IdHTTP1 : TIdHttp;
begin
  FreeOnTerminate:=true;
  ......
  IdHTTP1:=TIdHTTP.Create(nil);
  ......
  IdHTTP1.Get(aURL, tStream);
  ......
end;问题是原来程序的如下代码怎么改?(如下):
procedure IdHTTP1WorkEnd(Sender: TObject; AWorkMode: TWorkMode);
begin
  ProgressBar1.Position:=ProgressBar1.Max;
end;procedure IdHTTP1Status(ASender: TObject; const AStatus: TIdStatus;
  const AStatusText: String);
begin
  Memo_Update.Lines.Add(AStatusText);
end;
用原来的以上代码会提示Undeclared identifier:'TWorkMode'等错误.应该怎么改啊?我在界面上放的进度条,一定要用到啊,如果不用的话怎么判断下载了多少啊?

Answer 1

判断进度条的进度显示在 IdHTTP的 WorkBegin，Work，WorkEnd 3个事件里写代码  注意AWorkCount参数

Answer 2

可能是这个原因，在你的线程TThreadHttp.Execute;中，
...
IdHTTP1:=TIdHTTP.Create(nil);
...这个IdHTTP1是动态创建的，应该要设置好它的事件处理函数IdHTTP1:=TIdHTTP.Create(nil);
IdHTTP1.OnWorkEnd:=IdHTTP1Status;//加上这两句代码
IdHTTP1.OnStatus :=IdHTTP1WorkEnd;//

Answer 3

谢谢你们,我把我的代码都贴上来,希望你们帮忙一下!谢谢..
线程单元主要代码如下:
constructor TThreadHttp.create(myurl: string);
begin
  inherited Create(false);
  aURL:=myurl;
end;procedure TThreadHttp.Execute;
var
  tStream: TFileStream;
  aFile : string;
  IdHTTP1 : TIdHttp;
begin
  FreeOnTerminate:=true;
  IdHTTP1:=TIdHTTP.Create(nil);
  aFile:=GetURLFileName(aURL);//得到url最后一个文件名:如:如:http://localhost/aa/bb.exe,得到bb.exe
  if FileExists(aFile) then tStream := TFileStream.Create(aFile, fmOpenWrite)
  else tStream := TFileStream.Create(aFile, fmCreate);
  IdHTTP1.Request.ContentRangeStart := 0;
  try
    IdHTTP1.Get(aURL, tStream);
  except
    MessageBox(handle,PChar('请检查网络！'),'提示',MB_OK+MB_ICONINFORMATION);
    tStream.Free;
    IdHTTP1.Disconnect;
    Exit;
  end;
  tStream.Free;
  IdHTTP1.Disconnect;
end;主窗体单元主要代码如下:
procedure TUpdatefrm.sbnstartClick(Sender: TObject);
var
 XMLDocument :IXMLDocument;
 XMLNode :IXMLNode;
 i,j:integer;
 Node_name:string;
 ThreadDown1: TThreadHttp;
begin
  XMLDocument:=TXMLDocument.Create('http://aaa/aa/newversion.xml');
  XMLDocument.Active;
  XMLNode := XMLDocument.DocumentElement;
  j := XMLNode.ChildNodes.Count-1;
  for i:=0 to j do
  begin
    XMLNode := XMLDocument.DocumentElement;
    XMLNode:=XMLNode.ChildNodes.Nodes[i];
    if strtoint(XMLNode.Attributes['date'])>strtoint(nowversion_date) then //如果版本时间大于服务端的时间
    begin
      //Memo_Update.Lines.Add('即将下载数据：'+Node_name);
      Node_name:=XMLNode.NodeValue;
      ThreadDown1:=TThreadHttp.Create('http://aaa/aa/Down_Data/'+Node_name);
      //Memo_Update.Lines.Add('已成功下载！'+Node_name);
    end;
  end;
end;主窗体里有个progressbar,在没有弄成多线程时的代码如下:
procedure TUpdatefrm.IdHTTP1WorkEnd(Sender: TObject; AWorkMode: TWorkMode);
begin
  ProgressBar1.Position:=ProgressBar1.Max;
end;procedure TUpdatefrm.IdHTTP1Status(ASender: TObject;const AStatusText: String);
begin
  Memo_Update.Lines.Add(AStatusText);
  Memo_Update.Lines.Add('正在下载数据，请耐心等待');
end;procedure TUpdatefrm.IdHTTP1Work(Sender: TObject; AWorkMode: TWorkMode;
  const AWorkCount: Integer);
begin
  ProgressBar1.Position:=AWorkCount;
end;   procedure TUpdatefrm.IdHTTP1WorkBegin(Sender: TObject; AWorkMode: TWorkMode;
  const AWorkCountMax: Integer);
begin
  ProgressBar1.Max:=AWorkCountMax;
  ProgressBar1.Min:=0;
  ProgressBar1.Position:=0;
end;  改成了多线程后,我要把上面关于进度条的代码改一下用起来.应该怎么改?  

Answer 4

其中newversion.xml的文件如下:
<version ver="5.5.5.5">
   <Item1 date="20061205">a.exe</Item1>   
   <Item2 date="20061205">b.xml</Item2> 
   <Item3 date="20061205">c.txt</Item3> 
</version>
上面的关于xml的代码我是循环得到a.exe,b.xml,c.txt

Answer 5

zouansuifeng和do2008,谢谢你们关注!我是新手按你们说的,不太能上手写不出来,能具体给一下代码吗?如关于IdHTTP.work事件的
代码怎么写?参数怎么设?

Answer 6

http://community.csdn.net/Expert/topic/5220/5220328.xml?temp=.4521295已经回帖

Answer 7

好了，我写了一个demo，测试了一下，没有问题1.主窗口单元unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, IdBaseComponent, IdComponent, IdTCPConnection, IdTCPClient,
  IdHTTP, StdCtrls,XMLDoc,XMLIntf,Unit2, ComCtrls;type
  TForm1 = class(TForm)
    IdHTTP1: TIdHTTP;
    Button1: TButton;
    Memo_Update: TMemo;
    ProgressBar1: TProgressBar;
    procedure Button1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure IdHTTP1Status(ASender: TObject; const AStatus: TIdStatus;
      const AStatusText: String);
    procedure IdHTTP1Work(Sender: TObject; AWorkMode: TWorkMode;
      const AWorkCount: Integer);
    procedure IdHTTP1WorkBegin(Sender: TObject; AWorkMode: TWorkMode;
      const AWorkCountMax: Integer);
    procedure IdHTTP1WorkEnd(Sender: TObject; AWorkMode: TWorkMode);
  private
    { Private declarations }
  public
    { Public declarations }
    nowversion_date:string;
  end;var
  Form1: TForm1;implementation{$R *.dfm}procedure TForm1.Button1Click(Sender: TObject);
var
 XMLDocument :IXMLDocument;
 XMLNode :IXMLNode;
 i,j:integer;
 Node_name:string;
 ThreadDown1: TThreadHttp;
begin
  //http://127.0.0.1:8080/myapp/newversion.xml
  XMLDocument:=TXMLDocument.Create('http://127.0.0.1:8080/myapp/newversion.xml');
  XMLDocument.Active;
  XMLNode := XMLDocument.DocumentElement;
  j := XMLNode.ChildNodes.Count-1;
  for i:=0 to j do
  begin
    XMLNode := XMLDocument.DocumentElement;
    XMLNode:=XMLNode.ChildNodes.Nodes[i];
    if strtoint(XMLNode.Attributes['date'])>strtoint(nowversion_date) then //如果版本时间大于服务端的时间
    begin
      //Memo_Update.Lines.Add('即将下载数据：'+Node_name);
      Node_name:=XMLNode.NodeValue;
      ThreadDown1:=TThreadHttp.Create('http://127.0.0.1:8080/myapp/'+Node_name);
      //Memo_Update.Lines.Add('已成功下载！'+Node_name);
    end;
  end;
end;procedure TForm1.FormCreate(Sender: TObject);
begin
 nowversion_date :='20061205';
end;procedure TForm1.IdHTTP1Status(ASender: TObject; const AStatus: TIdStatus;
  const AStatusText: String);
begin
   Memo_Update.Lines.Add(AStatusText);
   //Memo_Update.Lines.Add('正在下载数据，请耐心等待');end;procedure TForm1.IdHTTP1Work(Sender: TObject; AWorkMode: TWorkMode;
  const AWorkCount: Integer);
begin
 ProgressBar1.Position:=AWorkCount;
end;procedure TForm1.IdHTTP1WorkBegin(Sender: TObject; AWorkMode: TWorkMode;
  const AWorkCountMax: Integer);
begin
  ProgressBar1.Max:=AWorkCountMax;
  ProgressBar1.Min:=0;
  ProgressBar1.Position:=0;end;procedure TForm1.IdHTTP1WorkEnd(Sender: TObject; AWorkMode: TWorkMode);
begin
  ProgressBar1.Position:=ProgressBar1.Max;  Memo_Update.Lines.Add('正在下载数据结束');
end;end.2.线程单元
unit Unit2;interfaceuses
  Classes, IdHTTP,SysUtils,Windows;type
  TThreadHttp = class(TThread)
  private
    { Private declarations }
    aURL: string;
  protected
    procedure Execute; override;
  public
    constructor create(myurl: string);
  end;
implementationuses Unit1;
constructor TThreadHttp.create(myurl: string);
begin
  inherited Create(false);
  aURL := myurl;
end;
function GetURLFileName(aURL: string): string;
var
  i: integer;
  s: string;
begin //返回下载地址的文件名
  s := aURL;
  i := Pos('/', s);
  while i<>0 do //去掉"/"前面的内容剩下的就是文件名了
  begin
    Delete(s, 1, i);
    i := Pos('/', s);
  end;
  Result := s;
end;procedure TThreadHttp.Execute;
var
  tStream: TFileStream;
  aFile: string;
  IdHTTP1: TIdHttp;
begin
  FreeOnTerminate := true;
  IdHTTP1 := TIdHTTP.Create(nil);
  IdHTTP1.OnStatus:=Form1.IdHTTP1Status;//加上这两句代码
  IdHTTP1.OnWork :=Form1.IdHTTP1Work;//
  IdHTTP1.OnWorkBegin:=Form1.IdHTTP1WorkBegin;//加上这两句代码
  IdHTTP1.OnWorkEnd :=Form1.IdHTTP1WorkEnd;//  aFile := GetURLFileName(aURL); //得到url最后一个文件名:如:如:http://localhost/aa/bb.exe,得到bb.exe
  if FileExists(aFile) then tStream := TFileStream.Create(aFile, fmOpenWrite)
  else tStream := TFileStream.Create(aFile, fmCreate);
  IdHTTP1.Request.ContentRangeStart := 0;
  try
    IdHTTP1.Get(aURL, tStream);
  except
    MessageBox(handle, PChar('请检查网络！'), '提示', MB_OK + MB_ICONINFORMATION);
    tStream.Free;
    IdHTTP1.Disconnect;
    Exit;
  end;
  tStream.Free;
  IdHTTP1.Disconnect;
end;
end.