WinForm改变无边框窗体大小

方法一 【优点：添加方便，通用 ； 缺点 边框有点大，大概有5像素，看着有点不舒服】 

 //定义窗体风格常量
        private const Int32 WS_THICKFRAME = 0x40000;
        private const Int32 WS_BORDER = 0x800000;


        protected override CreateParams CreateParams
        {
            get
            {
                CreateParams p = base.CreateParams;
                p.Style |= WS_THICKFRAME;  //是窗体可以改变大小
                p.Style &= ~WS_BORDER;  //去除边框
                return p;
            }
        }

方法二【优点，无边框；缺点：①操作费事些，代码多些 ②只能上下拖动大小，不能左右改变。③直接在要拖动的控件上操作，非拖动边框处（拖边框，只会改变此控件的大小，并且无法还原）】

添加引用： 

//using System.Runtime.InteropServices;

     

   [DllImport("user32.dll")]
        public static extern bool ReleaseCapture();
        [DllImport("user32.dll")]
        public static extern bool SendMessage(IntPtr hwnd, int wMsg, int wParam, int lParam);


        //常量
        public const int WM_SYSCOMMAND = 0x0112;


        //窗体移动
        public const int SC_MOVE = 0xF010;
        public const int HTCAPTION = 0x0002;   [DllImport("user32.dll")]
        public static extern bool ReleaseCapture();
        [DllImport("user32.dll")]
        public static extern bool SendMessage(IntPtr hwnd, int wMsg, int wParam, int lParam);


        //常量
        public const int WM_SYSCOMMAND = 0x0112;


        //窗体移动
        public const int SC_MOVE = 0xF010;
        public const int HTCAPTION = 0x0002;


        //改变窗体大小
        public const int WMSZ_LEFT = 0xF001;
        public const int WMSZ_RIGHT = 0xF002;
        public const int WMSZ_TOP = 0xF003;
        public const int WMSZ_TOPLEFT = 0xF004;
        public const int WMSZ_TOPRIGHT = 0xF005;
        public const int WMSZ_BOTTOM = 0xF006;
        public const int WMSZ_BOTTOMLEFT = 0xF007;
        public const int WMSZ_BOTTOMRIGHT = 0xF008;


        //窗体移动
        private void panel_title_bar_MouseDown(object sender, MouseEventArgs e)
        {
            ReleaseCapture();
            SendMessage(this.Handle, WM_SYSCOMMAND, SC_MOVE + HTCAPTION, 0);
        }
        //窗体大小的改变
        private void panel_bottom_MouseDown(object sender, MouseEventArgs e)
        {
            ReleaseCapture();
            SendMessage(this.Handle, WM_SYSCOMMAND, WMSZ_BOTTOM, 0);
        }


        //改变窗体大小
        public const int WMSZ_LEFT = 0xF001;
        public const int WMSZ_RIGHT = 0xF002;
        public const int WMSZ_TOP = 0xF003;
        public const int WMSZ_TOPLEFT = 0xF004;
        public const int WMSZ_TOPRIGHT = 0xF005;
        public const int WMSZ_BOTTOM = 0xF006;
        public const int WMSZ_BOTTOMLEFT = 0xF007;
        public const int WMSZ_BOTTOMRIGHT = 0xF008;


        //窗体移动
        private void panel_title_bar_MouseDown(object sender, MouseEventArgs e)
        {
            ReleaseCapture();
            SendMessage(this.Handle, WM_SYSCOMMAND, SC_MOVE + HTCAPTION, 0);
        }
        //窗体大小的改变 添加到一个控件上
        private void panel_bottom_MouseDown(object sender, MouseEventArgs e)
        {
            ReleaseCapture();
            SendMessage(this.Handle, WM_SYSCOMMAND, WMSZ_BOTTOM, 0);
        }

寻找更好的方法中。。。