将工具提示添加到C＃中的OvalShape

    bool hoverSeen = false;

    private void ovalShape1_MouseHover(object sender, EventArgs e) {
        if (!hoverSeen) {
            hoverSeen = true;
            // Todo, fix position
            Point pos = ovalShape1.Parent.PointToClient(Cursor.Position);
            toolTip1.Show("On oval", ovalShape1.Parent, pos);
        }
    }

    private void ovalShape1_MouseLeave(object sender, EventArgs e) {
        if (hoverSeen) toolTip1.Hide(ovalShape1.Parent);
        hoverSeen = false;
    }