procedure TGetDataThread.DoGetData;
var
FFile_Handle:THandle;
FFile_Map:THandle;
list:TStringList;
p:PChar;
i,interval:Integer;
begin
try
totallen := 0;
offset := 0;
tstream := TMemoryStream.Create;
stream := TMemoryStream.Create;
list := TStringList.Create;
//获取系统信息
GetSystemInfo(sysinfo);
//页面分配粒度大小
blocksize := sysinfo.dwAllocationGranularity;
//打开文件
FFile_Handle := CreateFile(PChar(FSourceFileName),GENERIC_READ,FILE_SHARE_READ,nil,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,0);
if FFile_Handle = INVALID_HANDLE_VALUE then Exit;
//获取文件尺寸
filesize := GetFileSize(FFile_Handle,nil);
//创建映射
FFile_Map := CreateFileMapping(FFile_Handle,nil,PAGE_READONLY,0,0,nil);
if FFile_Map = 0 then Exit;
//此处我们已10倍blocksize为一个数据块来映射，如果文件尺寸小于10倍blocksize，则直接映射整个文件长度
if filesize div blocksize > 10 then
readlen := 10*blocksize
else
readlen := filesize;
for i := 0 to FInfoList.Count - 1 do
begin
list.Delimiter := ':';
list.DelimitedText := FInfoList.Strings[i];
//取得长度，我这里做了解析，因为我存储的信息为 a:b:c 这种类型，所以以:号分隔
len := StrToInt(list.Strings[1]);
interval := StrToInt(list.Strings[2]);
if (i = 0) or (totallen+len >=readlen) then
begin
//如果已读取的长度加上即将要读取的长度大于 10倍blocksize，那么我们要保留之前映射末尾的内容，以便和新映射的内容合并
if i > 0 then
begin
offset := offset + readlen;
//写入临时流
tstream.Write(p^,readlen-totallen);
tstream.Position := 0;
end;
//如果未读取的数据长度已经不够一个分配粒度，那么就直接映射剩下的长度
if filesize-offset < blocksize then
readlen := filesize-offset;
//映射，p是指向映射区域的指针
//注意这里第三个参数，一直设为0，这个值要根据实际情况设置
p := PChar(MapViewOfFile(FFile_Map,FILE_MAP_READ,0,offset,readlen));
end;
//如果临时流中有数据，需要合并
if tstream.Size > 0 then
begin
//把临时流数据copy过来
stream.CopyFrom(tstream,tstream.Size);
//然后在末尾写入新数据，合并完成
stream.Write(p^,len-tstream.Size);
totallen := len-tstream.Size;
//移动指针的位置，指向下一个数据的开始
Inc(p,len-tstream.Size);
tstream.Clear;
end
else
begin
stream.Write(p^,len);
totallen := totallen + len;
Inc(p,len);
end;
stream.Position := 0;
//将流保存成文件
stream.SaveToFile(IntToStr(i)+'.txt');
stream.Clear;
end;
finally
stream.Free;
tstream.Free;
CloseHandle(FFile_Handle);
CloseHandle(FFile_Map);
end;
end;

unit  FileMap;  

interface  

uses  
   Windows,Messages,SysUtils,Classes,Graphics,Controls,Forms,StdCtrls,Dialogs;  

type  
   TFileMap=class(TComponent)  
   private  
       FMapHandle:THandle;                  //内存映射文件句柄  
       FMutexHandle:THandle;              //互斥句柄  
       FMapName:string;                        //内存映射对象  
       FSynchMessage:string;              //同步消息  
       FMapStrings:TStringList;        //存储映射文件信息  
       FSize:DWord;                                //映射文件大小  
       FMessageID:DWord;                      //注册的消息号  
       FMapPointer:PChar;                    //映射文件的数据区指针  
       FLocked:Boolean;                        //锁定  
       FIsMapOpen:Boolean;                  //文件是否打开  
       FExistsAlready:Boolean;          //是否已经建立过映射文件  
       FReading:Boolean;                      //是否正在读取内存文件数据  
       FAutoSynch:Boolean;                  //是否同步  
       FOnChange:TNotifyEvent;          //当内存数据区内容改变时  
       FFormHandle:Hwnd;                      //存储本窗口的窗口句柄  
       FPNewWndHandler:Pointer;  
       FPOldWndHandler:Pointer;  
       procedure  SetMapName(Value:string);  
       procedure  SetMapStrings(Value:TStringList);  
       procedure  SetSize(Value:DWord);  
       procedure  SetAutoSynch(Value:Boolean);  
       procedure  EnterCriticalSection;  
       procedure  LeaveCriticalSection;  
       procedure  MapStringsChange(Sender:TObject);  
       procedure  NewWndProc(var  FMessage:TMessage);  
   public  
       constructor  Create(AOwner:TComponent);override;  
       destructor  Destroy;override;  
       procedure  OpenMap;  
       procedure  CloseMap;  
       procedure  ReadMap;  
       procedure  WriteMap;  
       property  ExistsAlready:Boolean  read  FExistsAlready;  
       property  IsMapOpen:Boolean  read  FIsMapOpen;  
   published  
       property  MaxSize:DWord  read  FSize  write  SetSize;  
       property  AutoSynchronize:Boolean  read  FAutoSynch  write  SetAutoSynch;  
       property  MapName:string  read  FMapName  write  SetMapName;  
       property  MapStrings:TStringList  read  FMapStrings  write  SetMapStrings;  
       property  OnChange:TNotifyEvent  read  FOnChange  write  FOnChange;  
   end;  
implementation  
constructor  TFileMap.Create(AOwner:TComponent);  
begin  
   inherited  Create(AOwner);  
   FAutoSynch:=True;  
   FSize:=4096;  
   FReading:=False;  
   FMapStrings:=TStringList.Create;  
   FMapStrings.OnChange:=MapStringsChange;  
   FMapName:='Unique  &  Common  name';  
   FSynchMessage:=FMapName+'Synch-Now';  
   if  AOwner  is  TForm  then  
   begin  
       FFormHandle:=(AOwner  as  TForm).Handle;  
       FPOldWndHandler:=Ptr(GetWindowLong(FFormHandle,GWL_wNDPROC));  
       FPNewWndHandler:=MakeObjectInstance(NewWndProc);  
       if  FPNewWndHandler=nil  then  
           raise  Exception.Create('超出资源');  
       SetWindowLong(FFormHandle,GWL_WNDPROC,Longint(FPNewWndHandler));  
   end  
   else  raise  Exception.Create('组件的所有者应该是TForm');  
end;  
destructor  TFileMap.Destroy;  
begin  
   CloseMap;  
   SetWindowLong(FFormHandle,GWL_WNDPROC,Longint(FPOldWndHandler));  
   if  FPNewWndHandler<>nil  then  
       FreeObjectInstance(FPNewWndHandler);  
   FMapStrings.Free;  
   FMapStrings:=nil;  
   inherited  destroy;  
end;  
procedure  TFileMap.OpenMap;  
var  
   TempMessage:array[0..255]  of  Char;  
begin  
   if  (FMapHandle=0)  and  (FMapPointer=nil)  then  
   begin  
       FExistsAlready:=False;  
       FMapHandle:=CreateFileMapping($FFFFFFFF,nil,PAGE_READWRITE,0,FSize,PChar(FMapName)); 
       if  (FMapHandle=INVALID_HANDLE_VALUE)  or  (FMapHandle=0)  then  
           raise  Exception.Create('创建文件映射对象失败!')  
       else  
       begin  
           if  (FMapHandle<>0)  and  (GetLastError=ERROR_ALREADY_EXISTS)  then  
               FExistsAlready:=True;  //如果已经建立的话，就设它为TRUE；  
           FMapPointer:=MapViewOfFile(FMapHandle,FILE_MAP_ALL_ACCESS,0,0,0);  
           if  FMapPointer=nil  then  
               raise  Exception.Create('映射文件的视图到进程的地址空间失败')  
           else  
           begin  
               StrPCopy(TempMessage,FSynchMessage);  
               FMessageID:=RegisterWindowMessage(TempMessage);  
               if  FMessageID=0  then  
                   raise  Exception.Create('注册消息失败')  
           end  
       end;  
       FMutexHandle:=Windows.CreateMutex(nil,False,PChar(FMapName+'.Mtx'));  
       if  FMutexHandle=0  then  
           raise  Exception.Create('创建互斥对象失败');  
       FIsMapOpen:=True;  
       if  FExistsAlready  then  //判断内存文件映射是否已打开  
           ReadMap  
       else  
           WriteMap;  
   end;  
end;  
procedure  TFileMap.CloseMap;  
begin  
   if  FIsMapOpen  then  
   begin  
       if  FMutexHandle<>0  then  
       begin  
           CloseHandle(FMutexHandle);  
           FMutexHandle:=0;  
       end;  
       if  FMapPointer<>nil  then  
       begin  
           UnMapViewOfFile(FMapPointer);  
           FMapPointer:=nil;  
       end;  
       if  FMapHandle<>0  then  
       begin  
           CloseHandle(FMapHandle);  
           FMapHandle:=0;  
       end;  
       FIsMapOpen:=False;  
   end;  
end;  
procedure  TFileMap.ReadMap;  
begin  
   FReading:=True;  
   if(FMapPointer<>nil)  then  FMapStrings.SetText(FMapPointer);  
end;  
procedure  TFileMap.WriteMap;  
var  
   StringsPointer:PChar;  
   HandleCounter:integer;  
   SendToHandle:HWnd;  
begin  
   if  FMapPointer<>nil  then  
   begin  
       StringsPointer:=FMapStrings.GetText;  
       EnterCriticalSection;  
       if  StrLen(StringsPointer)+1<=FSize  
           then  System.Move(StringsPointer^,FMapPointer^,StrLen(StringsPointer)+1)  
       else  
           raise  Exception.Create('写字符串失败，字符串太大！');  
       LeaveCriticalSection;  
       SendMessage(HWND_BROADCAST,FMessageID,FFormHandle,0);  
       StrDispose(StringsPointer);  
   end;  
end;  
procedure  TFileMap.MapStringsChange(Sender:TObject);  
begin  
   if  FReading  and  Assigned(FOnChange)  then  
       FOnChange(Self)  
   else  if  (not  FReading)  and  FIsMapOpen  and  FAutoSynch  then  
       WriteMap;  
end;  
procedure  TFileMap.SetMapName(Value:string);  
begin  
   if  (FMapName<>Value)  and  (FMapHandle=0)  and  (Length(Value)<246)  then  
   begin  
       FMapName:=Value;  
       FSynchMessage:=FMapName+'Synch-Now';  
   end;  
end;  
procedure  TFileMap.SetMapStrings(Value:TStringList);  
begin  
   if  Value.Text<>FMapStrings.Text  then  
   begin  
       if  Length(Value.Text)<=FSize  then  
           FMapStrings.Assign(Value)  
       else  
           raise  Exception.Create('写入值太大');  
   end;  
end;  
procedure  TFileMap.SetSize(Value:DWord);  
var  
   StringsPointer:PChar;  
begin  
   if  (FSize<>Value)  and  (FMapHandle=0)  then  
   begin  
       StringsPointer:=FMapStrings.GetText;  
       if  (Value<StrLen(StringsPointer)+1)  then  
           FSize:=StrLen(StringsPointer)+1  
       else  FSize:=Value;  
       if  FSize<32  then  FSize:=32;  
       StrDispose(StringsPointer);  
   end;  
end;  
procedure  TFileMap.SetAutoSynch(Value:Boolean);  
begin  
   if  FAutoSynch<>Value  then  
   begin  
       FAutoSynch:=Value;  
       if  FAutoSynch  and  FIsMapOpen  then  WriteMap;  
   end;  
end;  
procedure  TFileMap.EnterCriticalSection;  
begin  
   if    (FMutexHandle<>0)  and  not  FLocked  then  
   begin  
       FLocked:=(WaitForSingleObject(FMutexHandle,INFINITE)=WAIT_OBJECT_0);  
   end;  
end;  
procedure  TFileMap.LeaveCriticalSection;  
begin  
   if  (FMutexHandle<>0)  and  FLocked  then  
   begin  
       ReleaseMutex(FMutexHandle);  
       FLocked:=False;  
   end;  
end;  
//消息捕获过程  
procedure  TFileMap.NewWndProc(var  FMessage:TMessage);  
begin  
   with  FMessage  do  
   begin  
       if  FIsMapOpen  
         if  (Msg=FMessageID)  and  (WParam<>FFormHandle)  then  
               ReadMap;  
       Result:=CallWindowProc(FPOldWndHandler,FFormHandle,Msg,wParam,lParam);  
   end;  
end;end.