Delphi10.2 关于Http 下载
演示如图：
代码如下：
1 unit Unit1; 2 3 interface 4 5 uses 6 Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics, 7 Vcl.Controls, Vcl.Forms, Vcl.Dialogs, IdComponent, Vcl.ComCtrls, Vcl.StdCtrls, 8 IdAntiFreezeBase, IdAntiFreeze, IdBaseComponent, IdTCPConnection, IdTCPClient, 9 IdHTTP; 10 11 type 12 TForm1 = class(TForm) 13 Label1: TLabel; 14 Label2: TLabel; 15 Edit1: TEdit; 16 Edit2: TEdit; 17 IdHTTP1: TIdHTTP; 18 IdAntiFreeze1: TIdAntiFreeze; 19 Button1: TButton; 20 ProgressBar1: TProgressBar; 21 Label3: TLabel; 22 Label4: TLabel; 23 Label5: TLabel; 24 Label6: TLabel; 25 procedure IdHTTP1WorkBegin(ASender: TObject; AWorkMode: TWorkMode; 26 AWorkCountMax: Int64); 27 procedure IdHTTP1Work(ASender: TObject; AWorkMode: TWorkMode; 28 AWorkCount: Int64); 29 procedure Button1Click(Sender: TObject); 30 private 31 { Private declarations } 32 public 33 { Public declarations } 34 end; 35 36 var 37 Form1: TForm1; 38 39 implementation 40 41 {$R *.dfm} 42 //1. 字节数转换为KB或MB字符串 43 function BytesToStr(iBytes: Integer): String; 44 var 45 iKb: Integer; 46 begin 47 iKb := Round(iBytes / 1024); 48 if iKb > 1000 then 49 Result := Format('%.2f MB', [iKb / 1024]) 50 else 51 Result := Format('%d KB', [iKb]); 52 end; 53 54 procedure TForm1.IdHTTP1WorkBegin(ASender: TObject; AWorkMode: TWorkMode; 55 AWorkCountMax: Int64); 56 begin 57 ProgressBar1.Max := AWorkCountMax; // 获取要下载的文件大小 58 Label2.Caption := BytesToStr(AWorkCountMax); 59 Update; 60 end; 61 62 procedure TForm1.IdHTTP1Work(ASender: TObject; AWorkMode: TWorkMode; 63 AWorkCount: Int64); 64 begin 65 Label1.Caption := BytesToStr(aWorkCount); //更新进度 66 ProgressBar1.Position := aWorkCount; //更新进度条 67 Update; 68 end; 69 70 71 procedure TForm1.Button1Click(Sender: TObject); 72 73 var 74 tStream: TMemoryStream; 75 begin 76 tStream := TMemoryStream.Create; 77 try 78 IdHTTP1.Get(Edit1.Text, tStream); //保存到内存流 （下载链接） 79 tStream.SaveToFile(Edit2.Text); //保存为文件 （路径） 80 ShowMessage('下载成功！'); 81 except 82 ShowMessage('下载失败！'); 83 end; 84 tStream.Free; 85 86 end; 87 88 89 end.
