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

namespace WCS_Client.From
{
    public partial class Form1 : Form
    {
        int zoomStep = 20;      //缩放步长
        bool ifNativeMouseWheelSupport = false;//鼠标滚轮是否有效
        Point mouseDownPoint = new Point(); //记录拖拽过程鼠标位置
        bool isMove = false;    //判断鼠标在picturebox上移动时，是否处于拖拽过程(鼠标左键是否按下)
        public Form1()
        {
            InitializeComponent();
        }
        private static Form1 childFromInstanc;
        public static Form1 ChildFromInstanc
        {
            get
            {
                if (childFromInstanc == null || childFromInstanc.IsDisposed)
                {
                    childFromInstanc = new Form1();
                }
                return childFromInstanc;
            }
        }

        private void tableLayoutPanel1_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                mouseDownPoint.X = Cursor.Position.X;
                mouseDownPoint.Y = Cursor.Position.Y;
                isMove = true;
            }
        }

        private void tableLayoutPanel1_MouseUp(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                isMove = false;
            }
        }

        private void tableLayoutPanel1_MouseMove(object sender, MouseEventArgs e)
        {
            tableLayoutPanel1.Focus();
            if (isMove)
            {
                int x, y;
                int moveX, moveY;
                moveX = Cursor.Position.X - mouseDownPoint.X;
                moveY = Cursor.Position.Y - mouseDownPoint.Y;
                x = tableLayoutPanel1.Location.X + moveX;
                y = tableLayoutPanel1.Location.Y + moveY;
                tableLayoutPanel1.Location = new Point(x, y);
                mouseDownPoint.X = Cursor.Position.X;
                mouseDownPoint.Y = Cursor.Position.Y;
            }
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            ifNativeMouseWheelSupport = SystemInformation.NativeMouseWheelSupport && SystemInformation.MouseWheelPresent;
            if (ifNativeMouseWheelSupport)//如果鼠标滚轮有效，就添加滚轮事件
                tableLayoutPanel1.MouseWheel += new MouseEventHandler(this.panel1_MouseWheel);

            //PanelScrollHelper.InitializePanelScroll(panel1);
            tableLayoutPanel1.Width = myPanel1.Width;
            tableLayoutPanel1.Height = myPanel1.Height;
        }
        //鼠标滚轮滚动功能
        private void panel1_MouseWheel(object sender, MouseEventArgs e)
        {
            int x = e.Location.X;
            int y = e.Location.Y;
            int ow = tableLayoutPanel1.Width;
            int oh = tableLayoutPanel1.Height;
            if (e.Delta > 0)
            {
                tableLayoutPanel1.Width += zoomStep;
                tableLayoutPanel1.Height += zoomStep;
            }
            if (e.Delta < 0)
            {
                if (tableLayoutPanel1.Width <= myPanel1.Width && tableLayoutPanel1.Height <= myPanel1.Height) return;

                tableLayoutPanel1.Width -= zoomStep;
                tableLayoutPanel1.Height -= zoomStep;
            }
            //int VX, VY;
            //VX = (int)((double)x * (ow - panel1.Width) / ow);
            //VY = (int)((double)y * (oh - panel1.Height) / oh);
            //panel1.Location = new Point(panel1.Location.X + VX, panel1.Location.Y + VY);
        }
        protected override void WndProc(ref Message m)
        {
            if (m.Msg == 0x0014) // 禁掉清除背景消息
                return;
            base.WndProc(ref m);
        }

        private void tableLayoutPanel1_Paint(object sender, PaintEventArgs e)
        {
            //绘制表格右、下边框
            Pen tpen = new Pen(Color.Black);
            tpen.Width = 1F;
            int x = tableLayoutPanel1.Bounds.X;
            int y = tableLayoutPanel1.Bounds.Y;
            int width = tableLayoutPanel1.Width;
            int height = tableLayoutPanel1.Height;
            //绘制矩形
            //Rectangle rectangle = new Rectangle(x, y, x + width, y + height);
            //e.Graphics.DrawRectangle(tpen, rectangle);
            //绘制底边
            e.Graphics.DrawLine(tpen, x, y + height, x + width, y + height);
            //绘制右边
            e.Graphics.DrawLine(tpen, x + width, y, x + width, y + height);
        }
    }
}