带进度的文件复制 - 回复 "冷风无泪" 的问题

问题来源: http://www.cnblogs.com/del/archive/2008/12/02/1066817.html#1389078

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本例效果图:

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代码文件:

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unit Unit1;



interface



uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, StdCtrls, ComCtrls;



type

  TForm1 = class(TForm)

    Button1: TButton;

    ProgressBar1: TProgressBar;

    procedure Button1Click(Sender: TObject);

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}



procedure TForm1.Button1Click(Sender: TObject);

const

  getPath = 'c:\temp\get.rar';

  setPath = 'c:\temp\set.rar';

var

  getStream,setStream: TFileStream;

  num, n: Integer;

  buf: PByte;

  BufSize,block: Integer;

begin



  if not FileExists(getPath) then

  begin

    ShowMessage('源文件不存在');

    Exit;

  end;



  getStream := TFileStream.Create(getPath, fmOpenRead or fmShareExclusive);

  setStream := TFileStream.Create(setPath, fmCreate);



  num := getStream.Size;

  setStream.Size := num;

  getStream.Position := 0;

  setStream.Position := 0;



  BufSize := num;

  block := BufSize div 100;

  GetMem(buf, BufSize);



  ProgressBar1.Max := 100;

  ProgressBar1.Min := 0;

  ProgressBar1.Position := 0;



  while num <> 0 do

  begin

    Application.ProcessMessages;

    n := block;

    if n > num then n := num;

    getStream.ReadBuffer(buf^, n);

    setStream.WriteBuffer(buf^, n);

    ProgressBar1.Position := Trunc((1 - num / BufSize) * 100);

    Dec(num, n);

  end;



  FreeMem(buf, BufSize);

  getStream.Free;

  setStream.Free;



  ShowMessage('复制完毕');

  ProgressBar1.Position := 0;

end;



end.


 
   

窗体文件:

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object Form1: TForm1

  Left = 0

  Top = 0

  Caption = 'Form1'

  ClientHeight = 104

  ClientWidth = 265

  Color = clBtnFace

  Font.Charset = DEFAULT_CHARSET

  Font.Color = clWindowText

  Font.Height = -11

  Font.Name = 'Tahoma'

  Font.Style = []

  OldCreateOrder = False

  Position = poDesktopCenter

  PixelsPerInch = 96

  TextHeight = 13

  object Button1: TButton

    Left = 96

    Top = 56

    Width = 75

    Height = 25

    Caption = 'Button1'

    TabOrder = 0

    OnClick = Button1Click

  end

  object ProgressBar1: TProgressBar

    Left = 8

    Top = 16

    Width = 249

    Height = 17

    TabOrder = 1

  end

end