关于dll资源释放的问题

Question

我在主表单中自定义了一个loaddll函数，在被调用的dll所包含的pas文件中有个showform函数，而且在调用的表单中创建了一个线程．调用后可以正常显示，但是当关闭调用的窗口时总是出现can change visible in  onshow or in onhide．源代码如下
主程序中的showform
procedure Tform1.LoadDll(dllFile :string);
var
//  libhandle: Thandle;
  ShowForm: TShowForm;
begin
      libhandle :=loadlibrary(pchar(dllFile));
      try
        if libhandle=0 then
          raise EdllLoadError.Create('调用功能模块失败!');
        @ShowForm := getprocaddress(libhandle,'ShowForm');
        if not( @showForm=nil) then
           ShowForm(Application)
        else
         //raiseLastwin32Error;
      finally
       // FreeLibrary(libhandle);
      end;
end;
dll中包含的pas 中的showform
procedure ShowForm(mainApp: TApplication);stdcall;
var
    ptr:PLongInt;
begin
  application.Handle:=mainApp.Handle;
  ptr:=@(Application.mainform);
  ptr^:=LongInt(mainApp.MainForm);
  form1:=Tform1.Create(mainApp.MainForm);   try
    begin
      form1.Show;
      form1.Visible:=true;
      form1.SetFocus;
    end
  finally
  end;
end;
请大家帮忙解决，这个问题已经烦了我好多天了

Answer 1

問題可能出在你的form1裡。
form1有什麼代碼麼？

Answer 2

我 在form1里面有一个 线程,是 用来进行初始化的,这个线程我只写了execute方法,那问题会不会是我的线程销毁问题,或者表单释放的问题??请问线程销毁和表单释放应该是 怎么 个顺序,用那些代码来写,还有我是不是用写下destroy方法??明天我把form1的代码贴上来,楼上的帮我看看 ,谢谢你了

Answer 3

我帮你加了两句释放的 试试dll中包含的pas 中的showform
procedure ShowForm(mainApp: TApplication);stdcall;
var
    ptr:PLongInt;
begin
  application.Handle:=mainApp.Handle;
  ptr:=@(Application.mainform);
  ptr^:=LongInt(mainApp.MainForm);
  form1:=Tform1.Create(mainApp.MainForm);
   try
    begin
      form1.Show;
      form1.Visible:=true;
      form1.SetFocus;
    end
  finally
    form1.free;
  end;
end;主程序中的showform
procedure Tform1.LoadDll(dllFile :string);
var
  libhandle: Integer;
  ShowForm: TShowForm;
begin
      libhandle :=loadlibrary(pchar(dllFile));
      try
        if libhandle=0 then
          raise EdllLoadError.Create('调用功能模块失败!');
        @ShowForm := getprocaddress(libhandle,'ShowForm');
        if not( @showForm=nil) then
           ShowForm(Application)
        else
         raiseLastwin32Error;
      finally
        FreeLibrary(libhandle);
      end;
end;这个DLL创建了就必须释放的，和前面的窗体一样 你动态生成了就释放掉
这样不容易构成异常 libhandle 定义成整型 如果为0的话那就调用失败

Answer 4

我的程序中的form1中的代码是这样的，大家帮看看吧
unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ExtCtrls, DB, ADODB;type
MyThread=class(TThread)
procedure Execute;override;
end;
  TForm1 = class(TForm)
    Memo1: TMemo;
    Label1: TLabel;
    Edit1: TEdit;
    Button1: TButton;
    ADODataSet1: TADODataSet;
    ADOConnection1: TADOConnection;
    Edit2: TEdit;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    Label2: TLabel;
    Label3: TLabel;
    Button5: TButton;
    Button6: TButton;
    Button7: TButton;
    Button8: TButton;
    Button9: TButton;
    Button10: TButton;
    Button11: TButton;
    Button12: TButton;
    Button13: TButton;
    Label4: TLabel;
    Timer1: TTimer;
    procedure FormActivate(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure Button1Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Edit2Click(Sender: TObject);
    procedure Edit1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure Button5Click(Sender: TObject);
    procedure Button6Click(Sender: TObject);
    procedure Button7Click(Sender: TObject);
    procedure Button8Click(Sender: TObject);
    procedure Button9Click(Sender: TObject);
    procedure Button10Click(Sender: TObject);
    procedure Button11Click(Sender: TObject);
    procedure Button12Click(Sender: TObject);
    procedure Button13Click(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
    procedure FormCreate(Sender: TObject);  private
    { Private declarations }
  public
    { Public declarations }
  end;
  procedure ShowForm(mainApp:TApplication);stdcall;
  var
    hwn:Thandle; //用于控制edit的句柄
    isready:boolean; //读卡器状态
    canQuery:boolean; //根据查询条件状态判断是否可以进行查询
    runTime:integer; //表单的存在时间
    CardInit:MyThread;
    Form1: TForm1;
  function checkCardReaderValid(iport:PByte):PChar;stdcall;external 'cardapi.dll';
  function getPersonMsg(iport:PByte):PChar;stdcall;external 'cardapi.dll';
  function resetCardReader(iport:PByte):PChar;stdcall;external 'cardapi.dll';
implementation{$R *.dfm}
procedure ShowForm(mainApp: TApplication);stdcall;
var
    ptr:PLongInt;
begin
  application.Handle:=mainApp.Handle;
  ptr:=@(Application.mainform);
  ptr^:=LongInt(mainApp.MainForm);
  form1:=Tform1.Create(mainApp.MainForm);   try
    begin
      form1.Show;
      form1.Visible:=true;
      form1.SetFocus;
    end
  finally
  end;
end;
procedure TForm1.FormActivate(Sender: TObject);
begin
    hwn:=edit1.Handle;
  if not edit1.Focused then edit1.SetFocus;  //输入焦点为edit1
  runTime:=20;
  timer1.Enabled:=true;
  CardInit:=MyThread.Create(true);
  CardInit.Execute;    canQuery:=false;//初始化后无输入条件时不可查询end;procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  isready:=false;
  runTime:=20;
  CardInit.Terminate;
  cardinit.Destroy;end;procedure TForm1.Button1Click(Sender: TObject);
var
  t:SystemTime;
  a:string;
begin
  if (canQuery<>true) then
  begin
    if (not (edit1.Text='')) and (not (edit2.Text='')) then
    canQuery:= true;
  end;if not canQuery then
showmessage('查询条件不足，请完善!')
else
begin
//保存查询日志到Access数据库
  windows.GetLocalTime(t);
  a:=(Format('%d-%d-%d   %d:%d:%d.%d',[t.wYear,t.wMonth,t.wDay,t.wHour,t.wMinute,t.wSecond,t.wMilliseconds]));
  adodataset1.Active:=true;
  adodataset1.Edit;
  adodataset1.Append;
  try
    adodataset1.FieldByName('DATE_TIME').AsString:=a;
    adodataset1.FieldByName('User').AsString:=edit1.text;
    adodataset1.FieldByName('Successful').AsBoolean:=false;
    adodataset1.Post;
  finally
    adodataset1.Active:=false;
  end;
  end;end;procedure TForm1.Button3Click(Sender: TObject);
begin
postmessage(hwn, WM_KEYDOWN, 50, 0);
end;procedure TForm1.Edit2Click(Sender: TObject);
begin
hwn:=edit2.Handle;
end;procedure TForm1.Edit1Click(Sender: TObject);
begin
hwn:=edit1.Handle;
end;procedure TForm1.Button2Click(Sender: TObject);
begin
postmessage(hwn, WM_KEYDOWN, 49, 0);
end;procedure TForm1.Button4Click(Sender: TObject);
begin
postmessage(hwn, WM_KEYDOWN, 51, 0);
end;procedure TForm1.Button5Click(Sender: TObject);
begin
postmessage(hwn, WM_KEYDOWN, 52, 0);
end;procedure TForm1.Button6Click(Sender: TObject);
begin
postmessage(hwn, WM_KEYDOWN, 53, 0);
end;procedure TForm1.Button7Click(Sender: TObject);
begin
postmessage(hwn, WM_KEYDOWN, 54, 0);
end;procedure TForm1.Button8Click(Sender: TObject);
begin
postmessage(hwn, WM_KEYDOWN, 55, 0);
end;procedure TForm1.Button9Click(Sender: TObject);
begin
postmessage(hwn, WM_KEYDOWN, 56, 0);
end;procedure TForm1.Button10Click(Sender: TObject);
begin
postmessage(hwn, WM_KEYDOWN, 57, 0);
end;procedure TForm1.Button11Click(Sender: TObject);
begin
postmessage(hwn, WM_KEYDOWN, 48, 0);
end;procedure TForm1.Button12Click(Sender: TObject);
begin
postmessage(hwn, WM_KEYDOWN, 88, 0);
end;procedure TForm1.Button13Click(Sender: TObject);
begin
postmessage(hwn, WM_KEYDOWN, VK_BACK, 0);
end;procedure Tform1.Timer1Timer(Sender: TObject);
var
  b:string;
begin
    runTime:=runTime-1;
    b:=inttostr(runTime);
    label4.Caption:='为保证信息安全该页将于'+b+'秒后关闭';
    if runTime=0 then
    begin      //timer1.Enabled:=false;
      //CardInit.Terminate;
      //CardInit.Destroy;
      form1.Close;
    end;
end;procedure MyThread.Execute;
var
   s,p:string;
   i,num:integer;
begin
  isready:=true;
  try
    //初始化设备
    s:= checkCardReaderValid(0);
    if Copy(s,0,1)='1' then
      form1.Memo1.Lines.Add('### 请放卡.......')
    else
      form1.Memo1.Lines.Add('*** 初始化错误......');    //开始读卡
    while  isready do
      begin
        Application.ProcessMessages;
        p:= getPersonMsg(0);
        if Copy(p,0,1)='1' then
         begin
         form1.Memo1.Lines.Add(p);
         num:=0;
         for i:=1 to length(p) do
         begin
            if copy(p,i,1)='|' then num:=num+1;
            if num=3 then
            begin
              form1.edit1.Text:=copy(p,i+2,18);
              canquery:=true; //通过读卡获取身份信息后查询可进行
              //button1.Enabled:=true;
            end;
         end;
//复位设备，准备下一次阅读
          resetCardReader(0);
         end;
         Sleep(1000);
      end;
  except
  end;end;procedure TForm1.FormCreate(Sender: TObject);
begin
//  CardInit:=MyThread.Create(true);
//  CardInit.Execute;
end;end.

Answer 5

我的这个程序是在调用完form1关闭后出现错误，错误的地方我想应该在线程的释放和表单的释放问题上，但是不知道怎么改，希望大家帮忙，小弟在这里先谢了