//步骤

//1.导入代码

//2.事件中添加form_1mousedown函数

//3.在load函数中定义AnimateWindow语句，注意有两个引用。

//4.DllImport若有错误，按shift+alt+F10添加第一个解决

 [System.Runtime.InteropServices.DllImport("user32.dll")]//api加载声明

        protected static extern bool AnimateWindow(IntPtr hWnd, int dwTime, int dwFlags);//定义AnimateWindow

        public const Int32 AW_BLEND = 0x00080000;

        public const Int32 AW_CENTER = 0x00000010;

        public const Int32 AW_ACTIVATE = 0x00020000;

        public const Int32 AW_HIDE = 0x00010000;

        public const Int32 AW_SLIDE = 0x00040000;

 public Form1()

        {

            InitializeComponent();

            SetClassLong(this.Handle, GCL_STYLE, GetClassLong(this.Handle, GCL_STYLE) | CS_DropSHADOW);//API函数加载 

    ，实现窗体边框阴影效果

            this.SetStyle(ControlStyles.UserPaint | ControlStyles.AllPaintingInWmPaint |     

ControlStyles.OptimizedDoubleBuffer, true);

        }

 #region 窗体拖动代码

        //

        public const int WM_NCLBUTTONDOWN = 0xA1;

        public const int HTCAPTION = 0x2;

        [DllImportAttribute("user32.dll")]

        public static extern int SendMessage(IntPtr hWnd, int Msg, int wParam, int lParam);

        [DllImportAttribute("user32.dll")]

        public static extern bool ReleaseCapture();

        private void Form1_MouseDown(object sender, MouseEventArgs e)//在窗体事件中手动添加，注意引用，无引用则无法完成

        {

            ReleaseCapture();

            SendMessage(Handle, WM_NCLBUTTONDOWN, HTCAPTION, 0);

        }

        #endregion

        #region 窗体边框阴影效果

        const int CS_DropSHADOW = 0x20000;

        const int GCL_STYLE = (-26);

        //声明win32 api

        [DllImport("user32.dll", CharSet = CharSet.Auto)]

        public static extern int SetClassLong(IntPtr hwnd, int nIndex, int deNewLong);

        [DllImport("user32.dll", CharSet = CharSet.Auto)]

        public static extern int GetClassLong(IntPtr hwnd, int nIndex);   #endregion

    

private void Form1_Load(object sender, EventArgs e)

            {

                AnimateWindow(this.Handle, 500, AW_BLEND | AW_CENTER | AW_ACTIVATE);

            }

private void Form1_FormClosing(object sender, FormClosingEventArgs e)

        {

            AnimateWindow(this.Handle, 500, AW_CENTER | AW_BLEND | AW_HIDE);

        }