使用Indy TIdHTTP下載文件

Question

我目前有一個程序可以從我的VPS下載文件並將其解壓縮。 我想直接從原始網站下載它，但它不起作用。 我要使其下載此鏈接：

https://bintray.com/oxidemod/builds/download_file?file_path=Oxide-Rust.zip

代替這個：

http://41.185.91.51/RSM/Oxide-Rust.zip

編輯：使用此鏈接：

https://dl.bintray.com/oxidemod/builds/Oxide-Rust.zip

即使使用SSL協議，也不起作用。

我正在使用RAD Studio 10.2 Tokyo。

我找到了以下帖子，但正在努力將其添加到當前項目中：

使用TIdHTTP INDY 10下載的文件

這是我當前的項目代碼：

unit uOxideModInstaller;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,
  System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.ExtCtrls, Vcl.ComCtrls,
  Vcl.StdCtrls, IdBaseComponent, IdComponent,
  IdTCPConnection, IdTCPClient, IdHTTP, System.Zip;

type

  TDownload = class;

  Tfrmoxidemodinstaller = class(TForm)
    lbl1: TLabel;
    pb1: TProgressBar;
    btn1: TButton;
    btn2: TButton;
    lblstatus: TLabel;
    procedure btn2Click(Sender: TObject);
    procedure btn1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

  TDownload = class(TThread)
  private
    httpclient: TIdHTTP;
    url: string;
    filename: string;
    maxprogressbar: integer;
    progressbarstatus: integer;
    procedure ExtractZip(ZipFile: string; ExtractPath: string);
    procedure idhttp1Work(ASender: TObject; AWorkMode: TWorkMode;
      AWorkCount: Int64);
    procedure idhttp1WorkBegin(ASender: TObject; AWorkMode: TWorkMode;
      AWorkCountMax: Int64);
    procedure UpdateProgressBar;
    procedure SetMaxProgressBar;
  protected
    procedure Execute; override;
  public
    constructor Create(CreateSuspended: boolean; aurl, afilename: string);
    destructor Destroy; override;
  end;

var
  frmoxidemodinstaller: Tfrmoxidemodinstaller;

implementation

{$R *.dfm}
{ Thread }

constructor TDownload.Create(CreateSuspended: boolean; aurl, afilename: string);
begin
  inherited Create(CreateSuspended);
  httpclient := TIdHTTP.Create(nil);
  httpclient.OnWorkBegin := idhttp1WorkBegin;
  httpclient.OnWork := idhttp1Work;
  url := aurl;
  filename := afilename;
end;

procedure TDownload.idhttp1Work(ASender: TObject; AWorkMode: TWorkMode;
  AWorkCount: Int64);
begin
  progressbarstatus := AWorkCount;
  Queue(UpdateProgressBar);

end;

procedure TDownload.idhttp1WorkBegin(ASender: TObject; AWorkMode: TWorkMode;
  AWorkCountMax: Int64);
begin
  maxprogressbar := AWorkCountMax;
  Queue(SetMaxProgressBar);
end;

procedure TDownload.Execute;
var
  Stream: TMemoryStream;
begin
  Stream := TMemoryStream.Create;
  try
    httpclient.Get(url, Stream);
    Stream.SaveToFile(filename);
  finally
    Stream.Free;
  end;
end;

procedure TDownload.UpdateProgressBar;
var
  ZipFile: string;
begin
  frmoxidemodinstaller.pb1.Position := progressbarstatus;
  frmoxidemodinstaller.lblstatus.Caption := 'Downloading...';

  if frmoxidemodinstaller.pb1.Position = frmoxidemodinstaller.pb1.Max then
  begin
    frmoxidemodinstaller.lblstatus.Caption := 'Done Downloading. Installing...';
    Sleep(2000);
    ExtractZip('oxide.zip', GetCurrentDir);
  end;
end;

procedure TDownload.SetMaxProgressBar;
begin
  frmoxidemodinstaller.pb1.Max := maxprogressbar;
end;

destructor TDownload.Destroy;
begin
  FreeAndNil(httpclient);
  inherited Destroy;
end;

{ TForm1 }

procedure TDownload.ExtractZip(ZipFile, ExtractPath: string);
begin
  if TZipFile.IsValid(ZipFile) then
  begin
    TZipFile.ExtractZipFile(ZipFile, ExtractPath);
    frmoxidemodinstaller.lblstatus.Caption := 'Oxide Installed!';
    DeleteFile(ZipFile);
  end
  else
  begin
    ShowMessage('Error installing oxide!');
    frmoxidemodinstaller.lblstatus.Caption := 'Error Installing Oxide!';
  end;
end;

procedure Tfrmoxidemodinstaller.btn1Click(Sender: TObject);
var
  DownloadThread: TDownload;
  link: string;
begin
  link := 'http://41.185.91.51/RSM/Oxide-Rust.zip';
  DownloadThread := TDownload.Create(true, link, 'oxide.zip');
  DownloadThread.FreeOnTerminate := true;
  DownloadThread.Start;
end;

procedure Tfrmoxidemodinstaller.btn2Click(Sender: TObject);
begin
  Close;
end;

end.

Answer 1

這個網址：

https://bintray.com/oxidemod/builds/download_file?file_path=Oxide-Rust.zip

返回到此URL的HTTP 302重定向：

https://dl.bintray.com/oxidemod/builds/Oxide-Rust.zip

因此，您需要處理HTTP重定向。 將TIdHTTP.HandleRedirects屬性設置為true（默認情況下為false）。

如果您使用的是Delphi 10.2 Tokyo或更高版本，則可以替代地使用Delphi自己的System.Net.HttpClient.THTTPClient 。 它不需要任何外部SSL庫，就像TIdHTTP一樣。 確保將THTTPClient.HandleRedirects屬性設置為true。

Answer 2

您需要為SSL分配IOHandler。

在您的uses子句中包含IdSSLOpenSSL，並在創建httpclient之后添加以下內容。

httpclient.IOHandler := TIdSSLIOHandlerSocketOpenSSL.Create(httpclient);

然后只需確保您的OpenSSL DLL位於可執行文件所在的路徑或相同的文件夾中即可。