public partial class GroundForm : Form
    {
        public GroundForm()
        {
            InitializeComponent();
        }

        private void display_Click(object sender, EventArgs e)
        {
            DropDownForm.Instance().ShowForm(); //顯示窗體
        }

        private void close_Click(object sender, EventArgs e)
        {
            DropDownForm.Instance().CloseForm(); //隱藏窗體
            //關閉窗體
            this.Close();
        }
    }

   public partial class DropDownForm : System.Windows.Forms.Form
    {
        #region 聲明的變量

        private System.Drawing.Rectangle Rect; //定義一個存儲矩形框的數組
        private FormState InfoStyle = FormState.Hide; //定義變量為隱藏
        static private DropDownForm dropDownForm = new DropDownForm(); //實例化當前窗體
        private static int AW_HIDE = 0x00010000;
        private static int AW_SLIDE = 0x00040000;
        private static int AW_VER_NEGATIVE = 0x00000008;

        #endregion

        #region 該窗體的構造方法

        public DropDownForm()
        {
            InitializeComponent();
            //初始化工作區(qū)大小
            System.Drawing.Rectangle rect = System.Windows.Forms.Screen.GetWorkingArea(this);
            this.Rect = new System.Drawing.Rectangle(rect.Right - this.Width - 1, rect.Bottom - this.Height - 1,
                this.Width, this.Height);
        }

        #endregion

        #region 調用API函數顯示窗體

        [DllImportAttribute("user32.dll")]
        private static extern bool AnimateWindow(IntPtr hwnd, int dwTime, int dwFlags);

        #endregion

        #region 鼠標控制圖片的變化

        private void pictureBox1_MouseEnter(object sender, EventArgs e)
        {
            for (int i = 0; i < imageList1.Images.Count; i++)
            {
                if (i == 1)
                    pictureBox1.Image = imageList1.Images[i];
            }
        }

        private void pictureBox1_MouseLeave(object sender, EventArgs e)
        {
            for (int i = 0; i < imageList1.Images.Count; i++)
            {
                if (i == 0)
                    pictureBox1.Image = imageList1.Images[i];
            }
        }

        #endregion

        #region 定義標識窗體移動狀態(tài)的枚舉值

        protected enum FormState
        {
            //隱藏窗體
            Hide = 0,

            //顯示窗體
            Display = 1,

            //顯示窗體中
            Displaying = 2,

            //隱藏窗體中
            Hiding = 3
        }

        #endregion

        #region 用屬性標識當前狀態(tài)

        protected FormState FormNowState
        {
            get { return this.InfoStyle; }
            set { this.InfoStyle = value; }
        }

        #endregion

        #region 顯示窗體

        public void ShowForm()
        {
            switch (this.FormNowState)
            {
                case FormState.Hide:
                    if (this.Height <= this.Rect.Height - 192) //當窗體沒有完全顯示時
                        this.SetBounds(Rect.X, this.Top - 192, Rect.Width, this.Height + 192); //使窗體不斷上移
                    else
                    {
                        this.SetBounds(Rect.X, Rect.Y, Rect.Width, Rect.Height); //設置當前窗體的邊界
                        this.FormNowState = FormState.Display; //設置當前窗體的操作狀態(tài)為顯示
                    }

                    AnimateWindow(this.Handle, 800, AW_SLIDE + AW_VER_NEGATIVE); //動態(tài)顯示本窗體
                    break;
            }
        }

        #endregion

        #region 關閉窗體

        public void CloseForm()
        {
            switch (this.FormNowState)
            {
                case FormState.Display: //顯示當前窗體
                    if (this.Top <= this.Rect.Bottom - 192) //如果窗體沒有完全隱藏
                    {
                        this.SetBounds(Rect.X, this.Top + 192, Rect.Width, this.Height - 192); //使窗體不斷下移
                    }
                    else
                    {
                        this.Close(); //隱藏當前窗體
                        this.FormNowState = FormState.Hide; //設置窗體的操作狀態(tài)為隱藏
                    }

                    break;
            }
        }

        #endregion

        #region 返回當前窗體的實例化對象

        static public DropDownForm Instance()
        {
            return dropDownForm;
        }

        #endregion

        #region 在窗體的關閉事件中進行動態(tài)關閉

        private void DropDownForm_FormClosing(object sender, FormClosingEventArgs e)
        {
            e.Cancel = true;
            AnimateWindow(this.Handle, 800, AW_SLIDE + AW_VER_NEGATIVE + AW_HIDE);
            this.Close();
        }

        #endregion
    }