89 lines
2.3 KiB
ObjectPascal
89 lines
2.3 KiB
ObjectPascal
unit U_CompressionFun;
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interface
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uses
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Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
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Dialogs, ComCtrls, ToolWin, ShlObj, cxShellCommon, cxControls,
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cxContainer, cxShellTreeView, cxShellListView, StdCtrls, BtnEdit,
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OleCtnrs, DB, ADODB,ZLib;
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procedure CompressionStream(var ASrcStream:TMemoryStream;ACompressionLevel:Integer = 2);
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procedure UnCompressionStream(var ASrcStream:TMemoryStream);
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implementation
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uses
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U_iniparam;
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////////////////////////////////////////////////////
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///////压缩流
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////////////////////////////////////////////////////
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procedure CompressionStream(var ASrcStream:TMemoryStream;ACompressionLevel:Integer = 2);
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var
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nDestStream:TMemoryStream;
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nTmpStream:TCompressionStream;
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nCompressionLevel:TCompressionLevel;
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begin
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ASrcStream.Position := 0;
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nDestStream := TMemoryStream.Create;
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try
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//级别
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case ACompressionLevel of
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0:nCompressionLevel := clNone;
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1:nCompressionLevel := clFastest;
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2:nCompressionLevel := clDefault;
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3:nCompressionLevel := clMax;
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else
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nCompressionLevel := clMax;
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end;
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//开始压缩
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nTmpStream := TCompressionStream.Create(nCompressionLevel,nDestStream);
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try
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ASrcStream.SaveToStream(nTmpStream);
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finally
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nTmpStream.Free;//释放后nDestStream才会有数据
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end;
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ASrcStream.Clear;
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ASrcStream.LoadFromStream(nDestStream);
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ASrcStream.Position := 0;
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finally
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nDestStream.Clear;
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nDestStream.Free;
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end;
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end;
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////////////////////////////////////////////////////
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///////解压缩流
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////////////////////////////////////////////////////
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procedure UnCompressionStream(var ASrcStream:TMemoryStream);
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var
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nTmpStream:TDecompressionStream;
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nDestStream:TMemoryStream;
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nBuf: array[1..512] of Byte;
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nSrcCount: integer;
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begin
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ASrcStream.Position := 0;
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nDestStream := TMemoryStream.Create;
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nTmpStream := TDecompressionStream.Create(ASrcStream);
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try
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repeat
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//读入实际大小
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nSrcCount := nTmpStream.Read(nBuf, SizeOf(nBuf));
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if nSrcCount > 0 then
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nDestStream.Write(nBuf, nSrcCount);
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until (nSrcCount = 0);
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ASrcStream.Clear;
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ASrcStream.LoadFromStream(nDestStream);
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ASrcStream.Position := 0;
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finally
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nDestStream.Clear;
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nDestStream.Free;
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nTmpStream.Free;
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end;
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end;
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end.
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