寻求用DLL完成数据查询的方法!急

Question

我想用一个有窗体的DLL完成数据查询的任务,谁有这方面的例子,请给我一个!不胜感谢!

Answer 1

动态库代码如下：
library MyForms;uses
  SysUtils,Classes,Forms,
  DLLForm in 'DLLForm.pas' {FormDLL};function ShowForm:Integer;stdcall;
  var
    FormDll:TFormDLL; 
  begin
    FormDll:=TFormDll.Create(Application);
    Result:=FormDll.showmodal;
    FormDll.Free;
  end;
  exports
      ShowForm;
{$R *.res}begin
end.
动态库中的窗体上主要有ADOConnection1，ADOQuery1，DataSource1，DBGrid1，BitBtn1，BitBtn2等控件；窗体代码如下：
unit DLLForm;
interface
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ExtCtrls, StdCtrls, Buttons, DB, ADODB, Grids, DBGrids, ActiveX,
  DBClient, MConnect, SConnect, DBTables;type
  TFormDLL = class(TForm)
    Panel1: TPanel;
    BitBtn1: TBitBtn;
    DataSource1: TDataSource;
    DBGrid1: TDBGrid;
    BitBtn2: TBitBtn;
    ADOConnection1: TADOConnection;
    ADOQuery1: TADOQuery;
    procedure BitBtn1Click(Sender: TObject);
    procedure BitBtn2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;var
  FormDLL: TFormDLL;
implementation
{$R *.dfm}
procedure TFormDLL.BitBtn1Click(Sender: TObject);
begin
  Close;
end;procedure TFormDLL.BitBtn2Click(Sender: TObject);
begin
  FormDLL.ADOQuery1.Active:=False;  
  FormDLL.ADOQuery1.SQL.Clear;
  FormDLL.ADOQuery1.SQL.Add('select * from test');
  FormDLL.ADOQuery1.Open;
end;
initialization
  CoInitialize(nil);
finalization
  CoUnInitialize;
end.
在应用程序中调用该DLL，应用程序代码如下：
unit UseDLL;
interface
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, ADODB,ActiveX, DB;type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;var
  Form1: TForm1;
  function ShowForm:Integer;stdcall;
  external'myforms.dll';
implementation{$R *.dfm}procedure TForm1.Button1Click(Sender: TObject);
begin
  ShowForm;//调用动态库myforms.dll中的函数
end;end.