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  • 关于 Delphi 中流的使用(10): 压缩与解压缩进度 回复 "ilst" 的问题

    问题来源: http://www.cnblogs.com/del/archive/2008/08/02/1022539.html#1275599

    本例是在这个例子的基础上修改的: http://www.cnblogs.com/del/archive/2008/01/01/1022539.html

    本例效果图:



    代码文件:
    unit Unit1;
    
    interface
    
    uses
      Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
      Dialogs, StdCtrls, ComCtrls;
    
    type
      TForm1 = class(TForm)
        Button1: TButton;
        Button2: TButton;
        ProgressBar1: TProgressBar;
        procedure Button1Click(Sender: TObject);
        procedure Button2Click(Sender: TObject);
        procedure CsProgress(Sender: TObject); {压缩的 OnProgress 事件}
        procedure DsProgress(Sender: TObject); {解压缩的 OnProgress 事件}
      end;
    
    var
      Form1: TForm1;
    
    implementation
    
    {$R *.dfm}
    
    uses Zlib;
    
    {压缩的 OnProgress 事件}
    procedure TForm1.CsProgress(Sender: TObject);
    begin
      ProgressBar1.Position := Integer(TCompressionStream(Sender).Position div 1024);
      Application.ProcessMessages;
    end;
    
    {解压缩的 OnProgress 事件}
    procedure TForm1.DsProgress(Sender: TObject);
    begin
      ProgressBar1.Position := Integer(TDecompressionStream(Sender).Position div 1024);
      Application.ProcessMessages;
    end;
    
    {压缩}
    procedure TForm1.Button1Click(Sender: TObject);
    var
      cs: TCompressionStream;
      fs,ms: TMemoryStream;
      num: Integer;
    begin
      fs := TMemoryStream.Create;
      fs.LoadFromFile('c:\temp\test.txt'); {我是用一个 15M 的文本文件测试的}
      num := fs.Size;
    
      ms := TMemoryStream.Create;
      ms.Write(num, SizeOf(num));
    
      cs := TCompressionStream.Create(clMax, ms);
    
      {在原来代码基础是添加这两行}
      ProgressBar1.Max := Integer(fs.Size div 1024);
      cs.OnProgress := CsProgress;
    
      fs.SaveToStream(cs);
      cs.Free;
    
      ms.SaveToFile('c:\temp\test.zipx');
    
      ms.Free;
      fs.Free;
    end;
    
    
    {解压缩}
    procedure TForm1.Button2Click(Sender: TObject);
    var
      ds: TDecompressionStream;
      fs,ms: TMemoryStream;    
      num: Integer;
    begin
      fs := TMemoryStream.Create;
      fs.LoadFromFile('c:\temp\test.zipx');
      fs.Position := 0;
      fs.ReadBuffer(num,SizeOf(num));
    
      ms := TMemoryStream.Create;
      ms.SetSize(num);
    
      ds := TDecompressionStream.Create(fs);
    
      {在原来代码基础是添加这两行}
      ProgressBar1.Max := Integer(ms.Size div 1024);
      ds.OnProgress := DsProgress;
    
      ds.Read(ms.Memory^, num);
    
      ms.SaveToFile('c:\temp\test2.txt');
    
      ds.Free;
      ms.Free;
      fs.Free;
    end;
    
    end.
    
    窗体文件:
    object Form1: TForm1
      Left = 0
      Top = 0
      Caption = 'Form1'
      ClientHeight = 136
      ClientWidth = 205
      Color = clBtnFace
      Font.Charset = DEFAULT_CHARSET
      Font.Color = clWindowText
      Font.Height = -11
      Font.Name = 'Tahoma'
      Font.Style = []
      OldCreateOrder = False
      PixelsPerInch = 96
      TextHeight = 13
      object Button1: TButton
        Left = 64
        Top = 24
        Width = 75
        Height = 25
        Caption = #21387#32553
        TabOrder = 0
        OnClick = Button1Click
      end
      object Button2: TButton
        Left = 64
        Top = 55
        Width = 75
        Height = 25
        Caption = #35299#21387#32553
        TabOrder = 1
        OnClick = Button2Click
      end
      object ProgressBar1: TProgressBar
        Left = 24
        Top = 97
        Width = 150
        Height = 17
        TabOrder = 2
      end
    end
    
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  • 原文地址:https://www.cnblogs.com/del/p/1258881.html
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