DLL里面的共享数据段怎么写? Delphi / Windows SDK/APIhttp://www.delphi2007.net/DelphiAPI/html/delphi_20061208112551103.html
DLL里面的共享数据段怎么写? 用delphi,谢谢!
怎么没人回啊!?
内存映射文件,Delphi好似没有共享段的声明。
楼上,不是吧,我现在的情况是在调用dll之前,先要向dll里传一个值,有什么方案可以解决?
仅仅是传值的话,就用正常的传值方法呗。
如果仅仅是传值,就不必要大动干戈了吧。
共享数据段是用来多个进程同时调用一个DLL时,做进程间通讯用途的。
我可以给你参考下我以前写过的关于 dll共享一个整数的例子 你可以参考下
library DLLMem;
{ Important note about DLL memory management: ShareMem must be the
first unit in your library's USES clause AND your project's (select
Project-View Source) USES clause if your DLL exports any procedures or
functions that pass strings as parameters or function results. This
applies to all strings passed to and from your DLL--even those that
are nested in records and classes. ShareMem is the interface unit to
the BORLNDMM.DLL shared memory manager, which must be deployed along
with your DLL. To avoid using BORLNDMM.DLL, pass string information
using PChar or ShortString parameters. }
uses
windows,
SysUtils,
Classes,
SHareMem in 'SHareMem.pas';
exports
setsharedata,getsharedata; //提供接口
{$R *.res}
begin //程序从这里进入
DllProc:=@DllEntrypoint;
DllEntryPoint(DLL_PROCESS_ATTACH);
end.
unit SHareMem;
interface
uses
SysUtils,windows;
type
Tsharedata=integer;
Psharedata=^Tsharedata;
const
sharedata_size=sizeof(Tsharedata);
mapfilenamw='DLLMem';
var
maphandle:Thandle;
sharedata:psharedata;
procedure opensharedata;
procedure closesharedata;
procedure setsharedata(value:Tsharedata);stdcall;
function getsharedata:Tsharedata;stdcall;
procedure DllEntrypoint (reason:dword);
implementation
procedure opensharedata; //把文件映射到内存
begin
maphandle:=CreateFileMapping($FFFFFFFF,nil,PAGE_READWRITE,0,sharedata_size,mapfilenamw);
//if maphandle=0 then Raise Exception('创建公有数据的buf不成功');
sharedata:=mapviewoffile(maphandle,File_Map_Write,0,0,sharedata_size);
end ;
procedure closesharedata; //取消内存映射文件
begin
UnMapViewOfFile(sharedata);
closehandle(maphandle);
end;
procedure setsharedata(value:Tsharedata);stdcall; //从程序中读入直到文件中
begin
sharedata^:=value;
end;
function getsharedata:Tsharedata;stdcall; //从文件中取出直
begin
result:=sharedata^;
end;
procedure DllEntrypoint (reason:dword); //入口函数,目的是把文件映射到内存或取消内存影射文件
begin
case reason of
Dll_PROCESS_ATTACH:opensharedata;
Dll_PROCESS_DETACH:closesharedata;
end;
end;
end.
如果你看得满意就给我点分吧
TMapFile