pdf文件格式多余内容的移除，解除llPDFLib5.2的限制

 1 ......
 2 uses shellAPI;
 3 
 4 const
 5   StrJSText : AnsiString = ‘\(app.viewerVersion>=5\)‘;  // 查找这部分的JavaScript脚本特征
 6 ......
 7 function RunDosCommand(const CommandLine: string): boolean;
 8 var
 9   HRead,HWrite:THandle;
10   StartInfo:TStartupInfo;
11   ProceInfo:TProcessInformation;
12   sa:TSecurityAttributes;
13 begin
14   FillChar(sa,sizeof(sa),0);
15   sa.nLength := sizeof(sa);
16   sa.bInheritHandle := True;
17   sa.lpSecurityDescriptor := nil;
18   CreatePipe(HRead,HWrite,@sa,0);
19 
20   FillChar(StartInfo,SizeOf(StartInfo),0);
21   StartInfo.cb := SizeOf(StartInfo);
22   StartInfo.wShowWindow := SW_HIDE;
23   StartInfo.dwFlags := STARTF_USESTDHANDLES or STARTF_USESHOWWINDOW;
24   StartInfo.hStdError := HWrite;
25   StartInfo.hStdInput := GetStdHandle(STD_INPUT_HANDLE);
26   StartInfo.hStdOutput := HWrite;
27   try
28     CreateProcess(nil,//lpApplicationName: PChar
29       PChar(CommandLine), //lpCommandLine: PChar
30       nil, //lpProcessAttributes: PSecurityAttributes
31       nil, //lpThreadAttributes: PSecurityAttributes
32       True, //bInheritHandles: BOOL
33       CREATE_NEW_CONSOLE,
34       nil,
35       nil,
36       StartInfo,
37       ProceInfo );
38     WaitForSingleObject(ProceInfo.hProcess,INFINITE);
39   except
40   end;
41   CloseHandle(HRead);
42   CloseHandle(HWrite);
43   Result := True;
44 end;
45 
46 { 更改JavaScript中IF条件的值，由>=5改为<-5，使条件永不成立。 }
47 procedure AlterJSIFValue(var srcPt: PAnsiChar; srcLen:Integer);
48 var jsPt : PAnsiChar;
49   i,j,jsLen : Integer;
50 begin
51   jsPt  := PAnsiChar(StrJSText);
52   jsLen := Length(StrJSText);
53   for i := 0 to srcLen-jsLen do
54   begin
55     for j := 0 to jsLen-1 do
56     if srcPt[i+j]<>jsPt[j] then break;
57     if j=jsLen then
58     begin
59       srcPt[i+j-5] := ‘<‘;
60       srcPt[i+j-4] := ‘-‘;
61       break; // 目前发现只有一处JavaScript，如果有多处，可注释此行。
62     end;
63   end;
64 end;
65 
66 ......
67 
68     if FPdf.FileName <> ‘‘ then
69     begin
70       dir := ExtractFilePath(FPdf.FileName);
71       fn := ExtractFileName(FPdf.FileName);
72       Delete(fn,Pos(ExtractFileExt(fn),fn),Length(fn)); // 去掉扩展名
73 
74       stream := TMemoryStream.Create;
75       stream.LoadFromFile(FPdf.FileName);
76       try
77         m := stream.Size;
78         pt := PAnsiChar(stream.Memory);
79         AlterJSIFValue(pt,m);
80         stream.Position := 0;
81         stream.SaveToFile(FPdf.FileName);
82         FreeAndNil(stream);
83 
84         cpdf := ‘cpdf.exe‘;
85         begin
86           dir := ExtractFilePath(FPdf.FileName);
87           ChgDosName(dir);
88           ChDir(dir);
89           cpdf := cpdf + ‘ -remove-annotations ‘ + fn + ‘.pdf -o ‘ + fn + ‘.pdf‘;
90           RunDosCommand(cpdf);
91         end;
92       except // 有异常，则将原始的及错误的，保存一份以便查原因。
93         if FileExists(FPdf.FileName) then
94           RenameFile(FPdf.FileName, dir + fn + ‘_bak.pdf‘);
95         stream.Position := 0;
96         stream.SaveToFile(dir + fn + ‘_err.pdf‘);
97       end;
98     end;