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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;
using System.Diagnostics;

namespace test2
{
    public partial class zeichenPanel : TableLayoutPanel
    {
        Rectangle clicked = new Rectangle();
        bool wasClick = false;

        public zeichenPanel()
        {
            this.MouseDown += drawPanel_MouseDown;
            this.MouseUp += drawPanel_MouseUp;
            this.CellBorderStyle = TableLayoutPanelCellBorderStyle.Single;
            this.Paint += drawPanel_Paint;
            this.MouseMove += drawPanel_MouseMove;
        }

        private void drawPanel_MouseDown(object sender, MouseEventArgs e)
        {
            int row = 0;
            int verticalOffset = 0;
            int clickx = e.X;
            int clicky = e.Y;
            foreach (int h in this.GetRowHeights())
            {
                int column = 0;
                int horizontalOffset = 0;
                foreach (int w in this.GetColumnWidths())
                {
                    Rectangle rectangle = new Rectangle(horizontalOffset, verticalOffset, w, h);
                    if (rectangle.Contains(e.Location))
                    {
                        clicked = rectangle;
                        wasClick = true;
                        this.Invalidate(rectangle);
                        return;
                    }
                    horizontalOffset += w;
                    column++;
                }
                verticalOffset += h;
                row++;
            }
        }
        private void drawPanel_MouseMove(object sender, MouseEventArgs e)
        {
            if (wasClick)
            {
                int row = 0;
                int verticalOffset = 0;
                int clickx = e.X;
                int clicky = e.Y;
                foreach (int h in this.GetRowHeights())
                {
                    int column = 0;
                    int horizontalOffset = 0;
                    foreach (int w in this.GetColumnWidths())
                    {
                        Rectangle rectangle = new Rectangle(horizontalOffset, verticalOffset, w, h);
                        if (rectangle.Contains(e.Location))
                        {
                            clicked = rectangle;
                            wasClick = true;
                            this.Invalidate(rectangle);
                            return;
                        }
                        horizontalOffset += w;
                        column++;
                    }
                    verticalOffset += h;
                    row++;
                }
            }          
        }

        void drawPanel_MouseUp(object sender, MouseEventArgs e)
        {
            wasClick = false;
        }

        private void drawPanel_Paint(object sender, PaintEventArgs e)
        {
            if (wasClick)
            {
                Graphics g = e.Graphics;
                Rectangle r = clicked;
                g.FillRectangle(Brushes.Red, r);
                //wasClick = false;
            }
        }
    }
}