这段dll动态生成adoquery的代码问题在哪里？(50分)

library moduleab;

uses
SysUtils,dialogs,adodb,
Classes;

procedure mainfunc(cnstring:string);stdcall;
var myado:tadoquery;
s:string;
i:integer;
begin
myado:=tadoquery.Create(nil);
myado.ConnectionString:='Provider=Microsoft.Jet.OLEDB.4.0;Data Source=E:/myaccess/myaccess.mdb;Persist Security Info=False';
with myado do
begin
close;
sql.Clear;
sql.Add('select * from order_info');
open;
first;
while not eof do
begin
for i:=0 to fieldcount-1 do
s:=s+Fields.AsString;
next;
end;
end;
showmessage(s);
end;

exports
mainfunc;

{$R *.res}

begin
end.

cnstring:string改成pchar
用string问题多多

用string传递，ShareMem必须有且在uses的最前
Important note about DLL memory management: ShareMem must be the
first unit in your library's USES clause AND your project's

还是不行，我都没有用那个参数

是什么问题？是程序不通呢？还是
showmessage(s);没内容？

"我都没有用那个参数"
你怎么调用dll

张剑波：我把参数改为pchar，然后随便赋一个
错误依旧，执行 myado:=tadoquery.Create(nil);的时候就过不去，报错eolesyserror

你uses activex;
在dll的初始化代码中执行 CoInitialize(nil);

接受答案了.