Delphi10.2 关于Http 下载

演示如图：

代码如下：

 unit Unit1;

 interface

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

 type
   TForm1 = class(TForm)
     Label1: TLabel;
     Label2: TLabel;
     Edit1: TEdit;
     Edit2: TEdit;
     IdHTTP1: TIdHTTP;
     IdAntiFreeze1: TIdAntiFreeze;
     Button1: TButton;
     ProgressBar1: TProgressBar;
     Label3: TLabel;
     Label4: TLabel;
     Label5: TLabel;
     Label6: TLabel;
     procedure IdHTTP1WorkBegin(ASender: TObject; AWorkMode: TWorkMode;
       AWorkCountMax: Int64);
     procedure IdHTTP1Work(ASender: TObject; AWorkMode: TWorkMode;
       AWorkCount: Int64);
     procedure Button1Click(Sender: TObject);
   private
     { Private declarations }
   public
     { Public declarations }
   end;

 var
   Form1: TForm1;

 implementation

 {$R *.dfm}
 //1. 字节数转换为KB或MB字符串
 function BytesToStr(iBytes: Integer): String;
 var
   iKb: Integer;
 begin
   iKb := Round(iBytes / );
   if iKb >  then
     Result := Format('%.2f MB', [iKb / ])
   else
     Result := Format('%d KB', [iKb]);
 end;

 procedure TForm1.IdHTTP1WorkBegin(ASender: TObject; AWorkMode: TWorkMode;
   AWorkCountMax: Int64);
 begin
   ProgressBar1.Max := AWorkCountMax;                // 获取要下载的文件大小
   Label2.Caption := BytesToStr(AWorkCountMax);
   Update;
 end;

 procedure TForm1.IdHTTP1Work(ASender: TObject; AWorkMode: TWorkMode;
   AWorkCount: Int64);
 begin
   Label1.Caption := BytesToStr(aWorkCount);      //更新进度
   ProgressBar1.Position := aWorkCount;           //更新进度条
   Update;
 end;

 procedure TForm1.Button1Click(Sender: TObject);

 var
   tStream: TMemoryStream;
 begin
   tStream := TMemoryStream.Create;
   try
     IdHTTP1.Get(Edit1.Text, tStream);       //保存到内存流 （下载链接）
     tStream.SaveToFile(Edit2.Text);         //保存为文件  （路径）
     ShowMessage('下载成功！');
   except
     ShowMessage('下载失败！');
   end;
   tStream.Free;

 end;

 end.