Paint2/Paint_2/ColorPicker.cs

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 Paint_2
{
    public partial class ColorPicker : Form
    {
        public Bitmap colorMap;
        public int RedLevel = 0;
        public int GreenLevel = 0;
        public int BlueLevel = 0;
        public Color SelectedColor;
        public Point cursorLocation;
        public PaintForm main;
        public ColorPicker(PaintForm theMainForm)
        {
            InitializeComponent();
            main = theMainForm;
        }

        private void ColorPicker_Load(object sender, EventArgs e)
        {
            colorMap = new Bitmap(255, 255);
            //SelectedColor = this.BackColor;
            SelectedColor = main.sketch.CurrentTool.Color;
            RedLevel = SelectedColor.R;
            RefreshUi();
        }
        private Bitmap RefreshMap(Bitmap map)
        {
            Graphics gr = Graphics.FromImage(map);
            for (int g = 0; g < 255; g += 1)
            {
                for (int b = 0; b < 255; b += 1)
                {
                    map.SetPixel(g, b, Color.FromArgb(255, RedLevel, g, b));
                }
            }
            return map;
        }
        private void RefreshUi()
        {
            
            pbxColor.Image = RefreshMap(colorMap);
            tbrRedLevel.Value = RedLevel;
            Color Scol = Color.FromArgb(SelectedColor.A, SelectedColor.R, SelectedColor.G, SelectedColor.B);
            nupRed.Value = Scol.R;
            nupGreen.Value = Scol.G;
            nupBlue.Value = Scol.B;
            nupGamma.Value = Scol.A;
            pbxSelectedColor.BackColor = SelectedColor;
            
            tbxColorHex.Text = ColorToHex(Scol);
        }

        private void tbrRedLevel_Scroll(object sender, EventArgs e)
        {
            RedLevel = tbrRedLevel.Value;
            RefreshUi();
        }

        private void pbxColor_Click(object sender, EventArgs e)
        {
            //Bitmap img = (Bitmap)pbxColor.Image;
            cursorLocation = pbxColor.PointToClient(MousePosition);
            SelectedColor = colorMap.GetPixel(cursorLocation.X, cursorLocation.Y);
            RefreshUi();
            //MessageBox.Show(cursorLocation.ToString()+Environment.NewLine+SelectedColor.ToString());
        }
        public static Color HexToColor(string rgb)
        {
            int toBase = 16;
            string raw = rgb;
            string cleaned = raw.Replace("#", String.Empty);
            Color result;
            if (cleaned.Length == 6)
            {
                try
                {
                    int r = Convert.ToInt32(String.Concat(cleaned[0], cleaned[1]), toBase);
                    int g = Convert.ToInt32(String.Concat(cleaned[2], cleaned[3]), toBase);
                    int b = Convert.ToInt32(String.Concat(cleaned[4], cleaned[5]), toBase);
                    result = Color.FromArgb(r, g, b);
                }
                catch (Exception e)
                {
                    Console.WriteLine(e);
                    result = default;
                }
            }
            else
            {
                result = default;
            }
            return result;
        }
        public static string ColorToHex(Color color)
        {
            int toBase = 16;
            string result = "#";

            if (color.R < toBase)
            {
                result += "0";
            }
            result += Convert.ToString(color.R, toBase);
            if (color.G < toBase)
            {
                result += "0";
            }
            result += Convert.ToString(color.G, toBase);
            if (color.B < toBase)
            {
                result += "0";
            }
            result += Convert.ToString(color.B, toBase);

            return result;
        }

        private void nupValueChanged(object sender, EventArgs e)
        {
            int tmpR = (int)nupRed.Value;
            int tmpG = (int)nupGreen.Value;
            int tmpB = (int)nupBlue.Value;
            int tmpA = (int)nupGamma.Value;

            if (tmpR >= 0 && tmpR <= 255 && tmpG >= 0 && tmpG <= 255 && tmpB >= 0 && tmpB <= 255 && tmpA >= 0 && tmpA <= 255)
            {
                Color newColor = Color.FromArgb(tmpA, tmpR, tmpG, tmpB);
                if (SelectedColor != newColor)
                {
                    SelectedColor = newColor;
                    RedLevel = tmpR;
                    RefreshUi();
                }
            }
        }

        private void tbxColorHex_TextChanged(object sender, EventArgs e)
        {
            Color tmp = HexToColor(tbxColorHex.Text);
            if (tmp != null)
            {
                if (SelectedColor != tmp)
                {
                    SelectedColor = tmp;
                    RedLevel = tmp.R;
                }
            }
        }

        private void ColorPicker_FormClosing(object sender, FormClosingEventArgs e)
        {
            main.sketch.ChangePaintToolColor(SelectedColor);
        }

        private void tbxColorHex_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Enter)
            {
                RefreshUi();
            }
        }
    }
}