如何从主程序向带窗体的DLL中传入变量和从DLL向主程序传变量.

Question

1:主程序登录时有个用户名变量,现在调用了一个带输入窗体的DLL,输入完一条记录时要添添加主程序中的变量用户,请问如何做,
2:在关闭DLL的输入窗体时如何把窗体上的cxtextedit1.TEXT的内容传到主程序的EDIT2.TEXT中.
我的主程序:
unit dll_tes;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;type
  Ttest = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Edit1: TEdit;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure Edit1Change(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;var
  test: Ttest;
  formref:longint;
function myshowform1(ahandle:thandle):longint;stdcall;
procedure mycloseform1(aformref:longint);stdcall;implementation
function myshowform1;external 'dll_1.dll';
procedure mycloseform1;external 'dll_1.dll';{$R *.dfm}procedure Ttest.Button1Click(Sender: TObject);
begin
formref:=myshowform1(application.handle);
//showmessage(inttostr(formref));end;procedure Ttest.Button2Click(Sender: TObject);
begin   mycloseform1(formref);test.Close;end;procedure Ttest.FormClose(Sender: TObject; var Action: TCloseAction);
begin
mycloseform1(formref);
end;procedure Ttest.Edit1Change(Sender: TObject);
beginend;end.DLL的程序:
library dll_1;
uses
  SysUtils,
  ActiveX,
  windows,
  Classes,
  sgdgd_tj in 'sgdgd_tj.pas' {Form1},
  SGDGD_TJDY in 'SGDGD_TJDY.pas' {Form12};
  procedure _DllProc(Reason: Integer);
begin
  //DLL装载时调用CoInitialize
  if Reason = DLL_PROCESS_ATTACH then
    CoInitialize(nil)
  else if Reason = DLL_PROCESS_DETACH then
  //DLL卸载时调用CoUninitialize
    CoUninitialize;
end;{$R *.res}
 exports
  myshowform1,
  mycloseform1;
begin
   DLLProc := @_DllProc;
  _DllProc(DLL_PROCESS_ATTACH); //装载end.

Answer 1

向DLL传，则在DLL中增加一个Procedure，DLL向主程序传，则在DLL当中加一个Callback。
或者也可以定义消息。

Answer 2

向DLL传是通过函数参数传，回传用回调函数

Answer 3

主程序
unit HostForm;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;type
  TfrmHost = class(TForm)
    edtUserName: TEdit;
    btnCallDLL: TButton;
    procedure btnCallDLLClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;  TOnGetUserName = procedure(NewName: PChar); stdcall;procedure TransParam(hApp: THandle; UserName: PChar;
  GetName: TOnGetUserName); stdcall; external 'Dll.Dll';var
  frmHost: TfrmHost;implementation{$R *.dfm}procedure DoGetUserName(NewName: PChar); stdcall;
begin
  frmHost.edtUserName.Text := NewName;
end;procedure TfrmHost.btnCallDLLClick(Sender: TObject);
begin
  TransParam(frmHost.Handle, PChar(edtUserName.Text), DoGetUserName);
end;end.

Answer 4

DLL程序
unit DllForm;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;type
  TfrmDLL = class(TForm)
    btnOk: TButton;
    edtUserName: TEdit;
    btnCancel: TButton;
    procedure btnCancelClick(Sender: TObject);
    procedure btnOkClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;  TOnGetUserName = procedure(NewName: PChar); stdcall;procedure TransParam(hApp: THandle; UserName: PChar;
  GetName: TOnGetUserName); stdcall; export;implementation{$R *.dfm}procedure TransParam(hApp: THandle; UserName: PChar;
  GetName: TOnGetUserName);
var
  frmDLL: TfrmDLL;
begin
  Application.Handle := hApp;
  frmDLL := TfrmDLL.Create(nil);
  try
    frmDLL.edtUserName.Text := UserName; //修改TfrmDLL上的文本框里内容为传入的UserName
    if Assigned(GetName) and (frmDLL.ShowModal = mrOk) then
      GetName(PChar(frmDLL.edtUserName.Text)); //把文本框内容回传(回调)给exe
  finally
    frmDLL.Free;
  end;
end;procedure TfrmDLL.btnCancelClick(Sender: TObject);
begin
  ModalResult := mrCancel;
end;procedure TfrmDLL.btnOkClick(Sender: TObject);
begin
  ModalResult := mrOk;
end;end.

Answer 5

TO blazingfire 
 在测试时提示:无法定位程序输入点Transparam于动态库DLL_1.DLL上.
我是跟据你的代码,加到我现有的DLL中的.如下:
主调程序:
unit dll_tes;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;type
  Ttest = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Edit1: TEdit;
    Button3: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure Button3Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;tongetusername=procedure(newname:pchar);stdcall;
procedure transparam(happ:thandle;username:pchar;
           getname:tongetusername);stdcall;external 'dll_1.dll';var
  test: Ttest;
  formref:longint;
function myshowform1(ahandle:thandle):longint;stdcall;
procedure mycloseform1(aformref:longint);stdcall;implementation
procedure togetusername(newname:pchar);stdcall;
begin
 test.Edit1.text:=newname;
end;function myshowform1;external 'dll_1.dll';
procedure mycloseform1;external 'dll_1.dll';{$R *.dfm}procedure Ttest.Button1Click(Sender: TObject);
begin
if formref<>0 then
  begin
  mycloseform1(formref);
  formref:=myshowform1(application.handle);
  end
 else
    begin
    formref:=myshowform1(application.handle);
    end;
end;procedure Ttest.Button2Click(Sender: TObject);
begin
 mycloseform1(formref);
 close;
end;procedure Ttest.FormClose(Sender: TObject; var Action: TCloseAction);
begin
end;
procedure Ttest.Button3Click(Sender: TObject);
begin
transparam(test.Handle ,pchar(edit1.text),togetusername);
end;
end.
把你的DLL部份代码加到了sgdgd_tj.pas(DLL中的窗体)中,原DLL代码没有变化.(不知这样对不对),如下: public
    { Public declarations }
  end;
  TONGETUSERNAME=PRocedure(newname:pchar);stdcall;
  Procedure transparam(Happ:Thandle;UserName:Pchar;
   Getname:Tongetusername);stdcall;export;var
  Form1: TForm1;  function myshowform1(ahandle:thandle):longint;stdcall;
  procedure mycloseform1(aformref:longint);stdcall;implementationuses Unit2, SGDGD_TJDY;
{$R *.dfm}Procedure TransParam(Happ:thandle;username:pchar;
  getname:tongetusername);
var
  form1:tform1;
begin
 Application.Handle:=happ;
  form1:=tform1.Create(nil);
  try
   form1.cxtextedit9.Text:=username;
   if assigned(getname)and(form1.showmodal=mrok)then
      getname(pchar(form1.cxTextEdit9.text));
   finally
    form1.Free;
   end;
end;
function myshowform1(ahandle:thandle):longint;
var
form1:tform1;
begin
 application.Handle:=ahandle;
 form1:=tform1.Create(application);
 form1.ShowModal;
 result:=longint(form1);
end;  procedure mycloseform1(aformref:longint);
   begin
    if aformref>0 then
       Tform1(aformref).free;
   end;
procedure TForm1.Button1Click(Sender: TObject);
begin
modalresult:=mrcancel;
end;procedure TForm1.Button2Click(Sender: TObject);
begin
modalresult:=mrok;
end;另:ModalResult是不是一个模式窗体的返回值呀,它有什么用?

Answer 6

exe向DLL传
dll:
EXE中的数据传到DLL中的G_dll
procdure GetValue( s: pchar);stdcall;
begin
  G_dll:= s;
end;exe:调用DLL中的GetValue过程
GetValue(G_dll);

Answer 7

EXE传到DLL我现在懂了,但从DLL传到EXE不是很清楚,请叫了...

Answer 8

delphi 一本书叫 windows核心编程里面有吧，先申请空间，mapping，然后怎么怎么的就可以了，下这书看看，我看了又忘了，看来还是要多看书呀