delphi NetHTTPClient1 下载显示进度条

unit untFrmDownFile;

interface

uses

Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,

Vcl.Controls, Vcl.Forms, Vcl.Dialogs, System.Net.URLClient,

System.Net.HttpClient, System.Net.HttpClientComponent, Vcl.ComCtrls,

Vcl.StdCtrls;

type

TFrmDown = class(TForm)

NetHTTPClient1: TNetHTTPClient;

ProgressBar1: TProgressBar;

Label1: TLabel;

procedure NetHTTPClient1RequestCompleted(const Sender: TObject;

const AResponse: IHTTPResponse);

procedure NetHTTPClient1ReceiveData(const Sender: TObject; AContentLength,

AReadCount: Int64; var Abort: Boolean);

procedure FormCreate(Sender: TObject);

procedure FormDestroy(Sender: TObject);

procedure FormShow(Sender: TObject);

private

{ Private declarations }

AResponse: TStringStream;

public

{ Public declarations }

FileName: string;

procedure DoDownload(Url: string);

end;

var

FrmDown: TFrmDown;

implementation

{$R *.dfm}

//delphi 字节数转换为KB或MB字符串

function BytesToStr(iBytes: Integer): String;

var

iKb: Integer;

begin

iKb := Round(iBytes / 1024);

if iKb > 1000 then

Result := Format('%.2f MB', [iKb / 1024])

else

Result := Format('%d KB', [iKb]);

end;

procedure TFrmDown.DoDownload(Url: string);

begin

AResponse.Clear;

NetHTTPClient1.Get(Url,AResponse);

end;

procedure TFrmDown.FormCreate(Sender: TObject);

begin

AResponse := TStringStream.Create('',TEncoding.UTF8);

end;

procedure TFrmDown.FormDestroy(Sender: TObject);

begin

FreeAndNil(AResponse);

end;

procedure TFrmDown.FormShow(Sender: TObject);

begin

ProgressBar1.Position := 0;

end;

procedure TFrmDown.NetHTTPClient1ReceiveData(const Sender: TObject;

AContentLength, AReadCount: Int64; var Abort: Boolean);

begin

ProgressBar1.Max := AContentLength;

ProgressBar1.Position := AReadCount;

Label1.Caption := BytesToStr(AReadCount) + ' / ' + BytesToStr(AContentLength);

end;

procedure TFrmDown.NetHTTPClient1RequestCompleted(const Sender: TObject;

const AResponse: IHTTPResponse);

begin

try

if AResponse.ContentStream.Size > 0 then

begin

if FileExists(FileName) then

DeleteFile(FileName);

Self.AResponse.SaveToFile(FileName);

Application.MessageBox('下载成功', '提示信息', MB_OK + MB_ICONINFORMATION);

Self.Close;

end;

except

Self.Close;

end;

end.

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