procedure TForm1.Button17Click(Sender: TObject);var Thd:FindForm;beginThd := FindForm.Create(False);thd.DoIt := True;Thd.MainWnd := Self.Handle;emrpd.Print(2) ; //弹出窗体Thd.DoIt := False;Thd.Free;end;

unit Unit2;interfaceuses  Classes,Windows,SysUtils,Messages;type  FindForm = class(TThread)  private    { Private declarations }  protected    procedure Execute; override;  public    MainWnd:THandle;    DoIt:Boolean;  end;implementationuses Unit1;{ Important: Methods and properties of objects in visual components can only be  used in a method called using Synchronize, for example,      Synchronize(UpdateCaption);  and UpdateCaption could look like,    procedure FindForm.UpdateCaption;    begin      Form1.Caption := ‘Updated in a thread‘;    end; }{ FindForm }  function ExFindChildWindow(const TopWnd, ParentWnd: HWND; const WindowClass, WindowName: string): HWND;var    ChdWnd, wnd: HWND;    sClass, sName: string;begin    ChdWnd := 0;    result := 0;    repeat        ChdWnd := FindWindowEx(TopWnd, ChdWnd, nil, nil);        if ChdWnd > 0 then        begin            sClass := GetClassNameByWnd(ChdWnd);            sName := GetTextByWnd(ChdWnd);            if ((WindowClass = sClass) or (WindowClass = ‘‘)) and ((WindowName = sName) or (Pos(WindowName, sName) > 0) or (WindowName = ‘‘)) then            begin              Result := ChdWnd;              Exit;            end            else            begin                wnd := ExFindChildWindow(ChdWnd, ParentWnd, WindowClass, WindowName);                if wnd > 0 then                begin                  Result := wnd;                   Exit;                end            end;        end;    until ChdWnd = 0;end;procedure FindForm.Execute;var  FormWnd:THandle;  FilePathWnd:THandle;  Edt_Hnd1,Edt_Hnd2,button_hnd1:THandle;  t:string;begin  { Place thread code here } while DoIt do begin FormWnd :=  ExFindChildWindow(0, MainWnd,‘‘, ‘行范围打印‘);   if formwnd >0  then   begin     form1.Caption := ‘Find:行范围打印,‘+‘Handle=‘+inttostr(FormWnd);      Edt_Hnd1 := FindWindowEx(FormWnd, 0, ‘Edit‘, ‘‘);      Edt_Hnd2 := GetWindow(Edt_Hnd1,GW_HWNDNEXT); //找到下一个 控件      button_hnd1 :=GetWindow(Edt_Hnd2,GW_HWNDNEXT);// 找到下一个 控件      form1.Caption := ‘Find:行范围打印,‘+‘Handle=‘+inttostr(FormWnd)+‘,EDT1= ‘      +inttostr(Edt_Hnd1)+‘,Edt2=‘+Inttostr(Edt_Hnd2)+‘,btn1=‘+ IntToStr(button_hnd1);      t:= ‘100‘;      sendmessage(Edt_Hnd1, WM_SETTEXT, 0, LongInt(t));   //赋值消息 WM_SETTEXT      sendmessage(Edt_Hnd2, WM_SETTEXT, 0, LongInt(t));      sendmessage(button_hnd1,WM_LBUTTONDOWN,0,0); //按下鼠标      sendmessage(button_hnd1,WM_LBUTTONUP,0,0);   //释放鼠标   相当于click//      sendmessage(button_hnd1,BN_CLICKED,0,0); //点击事件不起作用，不知为什么     DoIt := False;     Exit;   end; end; end;end.