using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Work.UserComponents
{
    public partial class UcTabControlMetro : TabControl
    {
        public UcTabControlMetro()
        {
            InitializeComponent();

            base.SetStyle(
                ControlStyles.UserPaint |                      // 控件将自行绘制，而不是通过操作系统来绘制
                ControlStyles.OptimizedDoubleBuffer |          // 该控件首先在缓冲区中绘制，而不是直接绘制到屏幕上，这样可以减少闪烁
                ControlStyles.AllPaintingInWmPaint |           // 控件将忽略 WM_ERASEBKGND 窗口消息以减少闪烁
                ControlStyles.ResizeRedraw |                   // 在调整控件大小时重绘控件
                ControlStyles.SupportsTransparentBackColor,    // 控件接受 alpha 组件小于 255 的 BackColor 以模拟透明
                true);                                         // 设置以上值为 true
            base.UpdateStyles();
            //this.SizeMode = TabSizeMode.Fixed;
        }

        private Color backgroundColor = Color.FromArgb(251, 251, 251);
        [Browsable(true), Category("自定义分组"), Description("Tab控件背景")]
        public Color BackgroundColor
        {
            get { return backgroundColor; }
            set
            {
                backgroundColor = value;
                this.Invalidate();
            }
        }

        private Color borderColor = Color.FromArgb(0, 174, 157);
        [Browsable(true), Category("自定义分组"), Description("Tab控件边框颜色")]
        public Color BorderColor
        {
            get { return borderColor; }
            set
            {
                borderColor = value;
                this.Invalidate();
            }
        }

        private Color tabSelectColor = Color.Red;
        [Browsable(true), Category("自定义分组"), Description("Tab选中颜色")]
        public Color TabSelectColor
        {
            get { return tabSelectColor; }
            set
            {
                tabSelectColor = value;
                this.Invalidate();
            }
        }

        private Color tabSelectTextColor = Color.Gray;
        [Browsable(true), Category("自定义分组"), Description("Tab选中文字颜色")]
        public Color TabSelectTextColor
        {
            get { return tabSelectTextColor; }
            set
            {
                tabSelectTextColor = value;
                this.Invalidate();
            }
        }

        private Color tabUnSelectTextColor = Color.White;
        [Browsable(true), Category("自定义分组"), Description("Tab未选中文字颜色")]
        public Color TabUnSelectTextColor
        {
            get { return tabUnSelectTextColor; }
            set
            {
                tabUnSelectTextColor = value;
                this.Invalidate();
            }
        }

        private bool showCloseButton = false;
        [Browsable(true), Category("自定义分组"), Description("显示关闭页面按钮")]
        public bool ShowCloseButton
        {
            get { return showCloseButton; }
            set
            {
                showCloseButton = value;
                this.Invalidate();
            }
        }

        Size oldSize = new Size();
        protected override void OnPaint(PaintEventArgs e)
        {
            if (TabPages.Count > 0 && oldSize.Width != this.Size.Width && this.SizeMode == TabSizeMode.Fixed)
            {
                //this.SizeMode = TabSizeMode.Fixed;
                this.ItemSize = new Size((int)Math.Floor(1.0 * (this.Width - 4) / TabPages.Count), 40);
                oldSize.Width = this.Size.Width;
            }

            // 绘制背景
            e.Graphics.FillRectangle(new SolidBrush(backgroundColor), new RectangleF(0, 0, this.Width, this.Height));

            // 绘制边框
            int startX = this.Margin.Left;
            int startY = this.Margin.Top;
            if (this.TabCount > 0)
            {
                startX = this.GetTabRect(0).Top;
                startY = this.GetTabRect(0).Bottom;
            }
            e.Graphics.DrawRectangle(new Pen(tabSelectColor), startX, startY, this.Width - this.Margin.Right - startX, this.Height - this.Margin.Bottom - startY);

            // 绘制tab控件
            for (int i = 0; i < this.TabCount; i++)
            {
                // 计算tab标题位置
                Rectangle bounds = this.GetTabRect(i);
                PointF textPoint = new PointF();
                SizeF textSize = TextRenderer.MeasureText(this.TabPages[i].Text, this.Font);
                // 加上每个标签的左偏移量X  
                textPoint.X = bounds.X + (bounds.Width - textSize.Width) / 2;
                textPoint.Y = bounds.Y + (bounds.Height - textSize.Height) / 2;

                // 当前选中的tab
                if (this.SelectedIndex == i)
                {
                    // 绘制tab框
                    var rect = this.GetTabRect(i);
                    // 底部和背景色相同
                    e.Graphics.DrawLine(new Pen(backgroundColor), new Point(rect.Left, rect.Bottom), new Point(rect.Right, rect.Bottom));
                    e.Graphics.DrawLine(new Pen(tabSelectColor), new Point(rect.Left, rect.Bottom), new Point(rect.Left, rect.Top));
                    e.Graphics.DrawLine(new Pen(tabSelectColor), new Point(rect.Left, rect.Top), new Point(rect.Right, rect.Top));
                    e.Graphics.DrawLine(new Pen(tabSelectColor), new Point(rect.Right, rect.Top), new Point(rect.Right, rect.Bottom));
                    // 绘制tab标题文字
                    //e.Graphics.TextRenderingHint = System.Drawing.Text.TextRenderingHint.SystemDefault;
                    e.Graphics.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAliasGridFit;
                    e.Graphics.DrawString(this.TabPages[i].Text, this.Font, new SolidBrush(tabSelectTextColor), textPoint.X, textPoint.Y);
                }
                else
                {
                    // 绘制tab框
                    e.Graphics.FillRectangle(new SolidBrush(tabSelectColor), this.GetTabRect(i));
                    // 绘制tab标题文字
                    //e.Graphics.TextRenderingHint = System.Drawing.Text.TextRenderingHint.SystemDefault;
                    e.Graphics.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAliasGridFit;
                    e.Graphics.DrawString(this.TabPages[i].Text, this.Font, new SolidBrush(tabUnSelectTextColor), textPoint.X, textPoint.Y);
                }

                // 绘制关闭按钮
                if (showCloseButton)
                {
                    using (Pen pen = new Pen(Color.Gray, 1f))
                    {
                        Point p1 = new Point(bounds.X + 10, bounds.Y + 10);
                        Point p2 = new Point(bounds.X + bounds.Width - 10, bounds.Y + bounds.Height - 10);
                        e.Graphics.DrawLine(pen, p1, p2);

                        Point p3 = new Point(bounds.X + 10, bounds.Y + bounds.Height - 10);
                        Point p4 = new Point(bounds.X + bounds.Width - 10, bounds.Y + 10);
                        e.Graphics.DrawLine(pen, p3, p4);
                    }
                }
            }
        }
    }
}