千呼万唤高手来，一个URLDOWNLOADTOFILE的问题！急！

Question

我需要写一个下载的程序，在网上找了一段创建一个线程类的代码，代码如下：
{ Delphi File Download Thread Class , Copyright (c) Zhou Zuoji }unit FileDownLoadThread;
interface
uses
    Classes,
    SysUtils,
    Windows,
    ActiveX,
    UrlMon;
const
    S_ABORT = HRESULT($80004004);
    
type
    TFileDownLoadThread = class;
    
    TDownLoadProcessEvent = procedure(Sender:TFileDownLoadThread;Progress, ProgressMax:Cardinal) of object;
    TDownLoadCompleteEvent = procedure(Sender:TFileDownLoadThread) of object ;
    TDownLoadFailEvent = procedure(Sender:TFileDownLoadThread;Reason:LongInt) of object ;
    TDownLoadMonitor = class( TInterfacedObject, IBindStatusCallback )
    private
        FShouldAbort: Boolean;
        FThread:TFileDownLoadThread;
    protected
        function OnStartBinding( dwReserved: DWORD; pib: IBinding ): HResult; stdcall;
        function GetPriority( out nPriority ): HResult; stdcall;
        function OnLowResource( reserved: DWORD ): HResult; stdcall;
        function OnProgress( ulProgress, ulProgressMax, ulStatusCode: ULONG;
            szStatusText: LPCWSTR): HResult; stdcall;
        function OnStopBinding( hresult: HResult; szError: LPCWSTR ): HResult; stdcall;
        function GetBindInfo( out grfBINDF: DWORD; var bindinfo: TBindInfo ): HResult; stdcall;
        function OnDataAvailable( grfBSCF: DWORD; dwSize: DWORD; formatetc: PFormatEtc;
            stgmed: PStgMedium ): HResult; stdcall;
        function OnObjectAvailable( const iid: TGUID; punk: IUnknown ): HResult; stdcall;
    public
        constructor Create(AThread:TFileDownLoadThread);
        property ShouldAbort: Boolean read FShouldAbort write FShouldAbort;
    end;
    TFileDownLoadThread = class( TThread )
    private
        FSourceURL: string;
        FSaveFileName: string;
        FProgress,FProgressMax:Cardinal;
        FOnProcess: TDownLoadProcessEvent;
        FOnComplete: TDownLoadCompleteEvent;
        FOnFail: TDownLoadFailEvent;
        FMonitor: TDownLoadMonitor;
    protected
        procedure Execute; override;
        procedure UpdateProgress(Progress, ProgressMax, StatusCode: Cardinal; StatusText:string);
        procedure DoUpdateUI;
    public
        constructor Create( ASrcURL, ASaveFileName: string; AProgressEvent:TDownLoadProcessEvent = nil;
          ACompleteEvent:TDownLoadCompleteEvent = nil;AFailEvent:TDownLoadFailEvent=nil;CreateSuspended: Boolean=False );
        property SourceURL: string read FSourceURL;
        property SaveFileName: string read FSaveFileName;
        property OnProcess: TDownLoadProcessEvent read FOnProcess write FOnProcess;
        property OnComplete: TDownLoadCompleteEvent read FOnComplete write FOnComplete;
        property OnFail: TDownLoadFailEvent read FOnFail write FOnFail;
    end;
implementation
constructor TDownLoadMonitor.Create(AThread: TFileDownLoadThread);
begin
    inherited Create;
    FThread:=AThread;
    FShouldAbort:=False;
end;
function TDownLoadMonitor.GetBindInfo( out grfBINDF: DWORD; var bindinfo: TBindInfo ): HResult;
begin
    result := S_OK;
end;
function TDownLoadMonitor.GetPriority( out nPriority ): HResult;
begin
    Result := S_OK;
end;
function TDownLoadMonitor.OnDataAvailable( grfBSCF, dwSize: DWORD; formatetc: PFormatEtc; stgmed: PStgMedium ): HResult;
begin
    Result := S_OK;
end;
function TDownLoadMonitor.OnLowResource( reserved: DWORD ): HResult;
begin
    Result := S_OK;
end;
function TDownLoadMonitor.OnObjectAvailable( const iid: TGUID; punk: IInterface ): HResult;
begin
    Result := S_OK;
end;
function TDownLoadMonitor.OnProgress( ulProgress, ulProgressMax, ulStatusCode: ULONG; szStatusText: LPCWSTR ): HResult;
begin
    if FThread<>nil then
        FThread.UpdateProgress(ulProgress,ulProgressMax,ulStatusCode,'');
    if FShouldAbort then
        Result := E_ABORT
    else
        Result := S_OK;
end;
function TDownLoadMonitor.OnStartBinding( dwReserved: DWORD; pib: IBinding ): HResult;
begin
    Result := S_OK;
end;
function TDownLoadMonitor.OnStopBinding( hresult: HResult; szError: LPCWSTR ): HResult;
begin
    Result := S_OK;
end;
{ TFileDownLoadThread }
constructor TFileDownLoadThread.Create( ASrcURL, ASaveFileName: string;AProgressEvent:TDownLoadProcessEvent ;
          ACompleteEvent:TDownLoadCompleteEvent;AFailEvent:TDownLoadFailEvent; CreateSuspended: Boolean );
begin
    if (@AProgressEvent=nil) or (@ACompleteEvent=nil) or (@AFailEvent=nil) then
        CreateSuspended:=True;
    inherited Create( CreateSuspended );
    FSourceURL:=ASrcURL;
    FSaveFileName:=ASaveFileName;
    FOnProcess:=AProgressEvent;
    FOnComplete:=ACompleteEvent;
    FOnFail:=AFailEvent;
end;
procedure TFileDownLoadThread.DoUpdateUI;
begin
     if Assigned(FOnProcess) then
        FOnProcess(Self,FProgress,FProgressMax);
end;
procedure TFileDownLoadThread.Execute;
var
    DownRet:HRESULT;
begin
    inherited;
    FMonitor:=TDownLoadMonitor.Create(Self);
    DownRet:= URLDownloadToFile( nil, PAnsiChar( FSourceURL ), PAnsiChar( FSaveFileName ), 0,FMonitor as IBindStatusCallback);
    if DownRet=S_OK then
    begin
        if Assigned(FOnComplete) then
            FOnComplete(Self);
    end
    else
    begin
        if Assigned(FOnFail) then
            FOnFail(Self,DownRet);
    end;
    FMonitor:=nil;
end;
procedure TFileDownLoadThread.UpdateProgress(Progress, ProgressMax, StatusCode: Cardinal; StatusText: string);
begin
    FProgress:=Progress;
    FProgressMax:=ProgressMax;
    Synchronize(DoUpdateUI);
    if Terminated then
        FMonitor.ShouldAbort:=True;
end;
end.
搞了几天，还是没办法调用这个类来下载文件，希望高手指点！

Answer 1

直接找作者http://hi.csdn.net/zhouzuoji

Answer 2

线程没有执行？还是执行了没有下载下来文件？在不使用线程的情况下是否可以下载文件，如果不可以检查一下web server的配置

Answer 3

constructor TFileDownLoadThread.Create( ASrcURL, ASaveFileName: string;AProgressEvent:TDownLoadProcessEvent ; 
          ACompleteEvent:TDownLoadCompleteEvent;AFailEvent:TDownLoadFailEvent; CreateSuspended: Boolean ); 
begin 
    if (@AProgressEvent=nil) or (@ACompleteEvent=nil) or (@AFailEvent=nil) then 
        CreateSuspended:=True; //如果你不指定这上面的三项参数，你的线程被挂起起了
    inherited Create( CreateSuspended ); 
    FSourceURL:=ASrcURL; 
    FSaveFileName:=ASaveFileName; 
    FOnProcess:=AProgressEvent; 
    FOnComplete:=ACompleteEvent; 
    FOnFail:=AFailEvent; 
end; 
//____________________//测试通过unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls,FileDownLoadThread;type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
    procedure DownLoadFail(Sender:TFileDownLoadThread;Reason:LongInt);
    procedure DownLoadProcess(Sender:TFileDownLoadThread;Progress, ProgressMax:Cardinal);
    procedure DownLoadComplete(Sender:TFileDownLoadThread);
  public
    { Public declarations }
  end;var
  Form1: TForm1;implementation
{$R *.dfm}procedure TForm1.Button1Click(Sender: TObject);
begin
  TFileDownLoadThread.Create('http://www.xxx.com/xxx/client.exe','c:\123.exe',DownLoadProcess,DownLoadComplete,DownLoadFail,false);
end;procedure TForm1.DownLoadComplete(Sender: TFileDownLoadThread);
begin
  showmessage('OK.');
end;procedure TForm1.DownLoadFail(Sender: TFileDownLoadThread;
  Reason: Integer);
begin
  showmessage('failed.');
end;procedure TForm1.DownLoadProcess(Sender: TFileDownLoadThread; Progress,
  ProgressMax: Cardinal);
begin
  //弄个进度条
end;end.