取消自动创建窗体 Form1关键代码 implementation uses Unit2; {$R *.dfm} procedure TForm1.Button1Click(Sender: TObject); begin if not Assigned(Form2) then //assigned 是用来判断某一指针(pointer)或过程引用是否为nil(空),如果为空则返回假(false). begin Form2 := TForm2.Create(Self); Form2.Show; en
1.如果要创建一个mdi child,先看是否有这个child 存在,如果有,则用它,如果没有再创建 //该函数判断MDI 子窗体是否存在,再进行创建和显示function isInclude(formclass: TFormClass): boolean;var i: Integer; form: TObject;begin result := false; for i := 0 to frmMain.MDIChildCount do begin form := frmMain
//第一种方式 procedure TForm1.btn1Click(Sender: TObject); begin With TForm2.Create(Application) do Try ShowModal; finally free; end; end; //第二种方式 procedure TForm1.btn2Click(Sender: TObject); begin if not assigned(Form2) then begin Form2:=TForm2.Create(nil
procedure TForm1.FormCreate(Sender: TObject); var hr :thandle; begin hr:=createroundrectrgn(1,1,width-2,height-2,5,5); setwindowrgn(handle,hr,true); end;