unit Unit2;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs;

type
  TForm2 = class(TForm)
    procedure FormShow(Sender: TObject);
  private
    fIsCommopen: Boolean;
      procedure OpenCom(DllName: string);
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form2: TForm2;
    newh: hwnd;

implementation
  uses
  U_iniParam;
{$R *.dfm}
 procedure TForm2.OpenCom(DllName: string);
type
  TMyFunc = function(fhandle: hwnd; sCommName: PAnsiChar; IntTime: Integer; IsMessage: Integer): hwnd; stdcall;
var
  Tf: TMyFunc;
  Tp: TFarProc;
  Th: Thandle;
begin
  Th := LoadLibrary(pchar(trim(DllName)));
  if Th > 0 then
  begin
    try
      Tp := GetProcAddress(Th, 'CommOpen');
      if Tp <> nil then
      begin
        Tf := TMyFunc(Tp);
        newh := Tf(Self.Handle, 'Comm1', 500, 1);
        if newh < 1 then
        begin
          Application.MessageBox(pchar('打开串口失败！'), '提示');
        end
        else
          fIsCommopen := true;
      end
      else
      begin
        fIsCommopen := false;
      end;
    finally
//       FreeLibrary(Th);
    end;
  end
  else
  begin
    fIsCommopen := false;
    Application.MessageBox(pchar('找不到 ' + trim(DllName) + ' 文件！'), '提示');
  end;
end;
procedure TForm2.FormShow(Sender: TObject);
begin
  if trim(MBDYDllName) <> '' then
      OpenCom(MBDYDllName);
end;

end.