RegisterClass(TForm1)和Application.CreateFrom(...)。。。。。

Question

RegisterClass//注册类
Application.CreateForm(Form1, TForm1)//创建一个窗体给程序

Answer 1

RegisterClass//注册类
Application.CreateForm(Form1, TForm1)//创建一个窗体给程序

Answer 2

//试试就明白了
procedure TForm1.Button1Click(Sender: TObject);
begin
  if Assigned(GetClass('TForm1')) then
    ShowMessage('1-找到')
  else ShowMessage('1-没找到');
  RegisterClass(TForm1);
  if Assigned(GetClass('TForm1')) then
    ShowMessage('2-找到')
  else ShowMessage('2-没找到');
  UnRegisterClass(TForm1);
  if Assigned(GetClass('TForm1')) then
    ShowMessage('3-找到')
  else ShowMessage('3-没找到');
end;