using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Drawing2D;
using System.Runtime.InteropServices;

namespace TestProject
{
    public partial class UserPanel : Panel
    {

        //所有用到了headBar的部分都需要这段代码
        [DllImport("user32.dll")]
        public static extern bool ReleaseCapture();

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

        [DllImport("user32.dll", EntryPoint = "GetWindowLong", CharSet = CharSet.Auto)]
        public static extern int GetWindowLong(HandleRef hWnd, int nIndex);

        [DllImport("user32.dll", EntryPoint = "SetWindowLong", CharSet = CharSet.Auto)]
        public static extern IntPtr SetWindowLong(HandleRef hWnd, int nIndex, int dwNewLong);

        public const int WM_SYSCOMMAND = 0x0112;
        public const int SC_MOVE = 0xF010;
        public const int HTCAPTION = 0x0002;

        public UserPanel()
        {
            InitializeComponent();
        }

        private void UserPanel_Paint(object sender, PaintEventArgs e)
        {
            Graphics g = e.Graphics;
            Pen p = new Pen(Color.CadetBlue, 2);
            Rectangle rect = new Rectangle(this.Location, this.Size);
            LinearGradientBrush b3 = new LinearGradientBrush(rect, Color.LightSkyBlue, Color.White, LinearGradientMode.Vertical);
            g.FillRectangle(Brushes.White, rect);
            g.DrawString("通知公告", new Font("微软雅黑", 14F, FontStyle.Regular, GraphicsUnit.Point, 134), Brushes.Black, this.Width / 2 - 40, 2);
            //绘制关闭按钮
            b3 = new LinearGradientBrush(rect, Color.IndianRed, Color.White, LinearGradientMode.Vertical);
            rect = new Rectangle(new Point(this.Location.X + this.Size.Width - this.Size.Height, 0), new Size(this.Size.Height, this.Size.Height));
            //绘制关闭按钮
            GraphicsPath Rect = CreateRoundedRectanglePath(rect, 1);
            g.FillPath(Brushes.Tomato, Rect);
            g.DrawLine(new Pen(Color.White, 4), new Point(this.Location.X + this.Size.Width - this.Size.Height + 12, 12), new Point(this.Location.X + this.Size.Width - 12, this.Size.Height - 12));
            g.DrawLine(new Pen(Color.White, 4), new Point(this.Location.X + this.Size.Width - this.Size.Height + 12, this.Size.Height - 12), new Point(this.Location.X + this.Size.Width - 12, 12));
            //绘制最小化按钮
            rect = new Rectangle(new Point(this.Location.X + this.Size.Width - this.Size.Height * 2 - 10, 0), new Size(this.Size.Height, this.Size.Height));
            //使用路径绘制
            Rect = CreateRoundedRectanglePath(rect, 1);
            g.FillPath(Brushes.Tomato, Rect);
            g.DrawLine(new Pen(Color.White, 4), new Point(this.Location.X + this.Size.Width - this.Size.Height * 2, 20), new Point(this.Location.X + this.Size.Width - this.Size.Height - 20, 20));
        }

        internal static GraphicsPath CreateRoundedRectanglePath(Rectangle rect, int cornerRadius)
        {
            GraphicsPath roundedRect = new GraphicsPath();
            roundedRect.AddArc(rect.X, rect.Y, cornerRadius * 2, cornerRadius * 2, 180, 90);
            roundedRect.AddLine(rect.X + cornerRadius, rect.Y, rect.Right - cornerRadius * 2, rect.Y);
            roundedRect.AddArc(rect.X + rect.Width - cornerRadius * 2, rect.Y, cornerRadius * 2, cornerRadius * 2, 270, 90);
            roundedRect.AddLine(rect.Right, rect.Y + cornerRadius * 2, rect.Right, rect.Y + rect.Height - cornerRadius * 2);
            roundedRect.AddArc(rect.X + rect.Width - cornerRadius * 2, rect.Y + rect.Height - cornerRadius * 2, cornerRadius * 2, cornerRadius * 2, 0, 90);
            roundedRect.AddLine(rect.Right - cornerRadius * 2, rect.Bottom, rect.X + cornerRadius * 2, rect.Bottom);
            roundedRect.AddArc(rect.X, rect.Bottom - cornerRadius * 2, cornerRadius * 2, cornerRadius * 2, 90, 90);
            roundedRect.AddLine(rect.X, rect.Bottom - cornerRadius * 2, rect.X, rect.Y + cornerRadius * 2);
            roundedRect.CloseFigure();
            return roundedRect;
        }

        private void UserPanel_MouseDown(object sender, MouseEventArgs e)
        {
            ReleaseCapture();
            SendMessage(Handle, WM_SYSCOMMAND, SC_MOVE + HTCAPTION, 0);
            if (e.Location.X >= this.Location.X + this.Size.Width - this.Size.Height)
            {
                this.FindForm().Close();
            }
            if (e.X > this.Location.X + this.Size.Width - this.Size.Height * 2 && e.X < this.Location.X + this.Size.Width - this.Size.Height - 20)
            {
                FindForm().WindowState = FormWindowState.Minimized;
            }
        }
    }
}