delphi 中tab order中listBox元素拖动如何实现.就是在要在鼠标指向的哪一行显示一个虚线框,如何实现.我在ondragover中这样写, 可是虚线框不断闪动, 移动过后虚线框不消失procedure TFormMain.ListBox1DragOver(Sender, Source: TObject; X, Y: Integer;
State: TDragState; var Accept: Boolean);
var
k: Integer;
Rct: TRect;
begin
Accept := true; k := y div ListBox1.ItemHeight;
Rct := ListBox1.ItemRect(k);
ListBox1.Canvas.DrawFocusRect(Rct);
end;
State: TDragState; var Accept: Boolean);
var
k: Integer;
Rct: TRect;
begin
Accept := true; k := y div ListBox1.ItemHeight;
Rct := ListBox1.ItemRect(k);
ListBox1.Canvas.DrawFocusRect(Rct);
end;
ListBox1.Canvas.DrawFocusRect(Rct);