Source code

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Drawing.Imaging;
using System.Diagnostics;

Source code

Stopwatch sw = new Stopwatch();
            Bitmap Screenshot;
            Graphics gfx;
            Color pixelColor;
            string color,R,G,B;
            int position = 0;
            int tempInt = 0;
            string[,] hexArray = new string[Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height];

            sw.Start();
            
            Screenshot = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height, PixelFormat.Format32bppArgb);
            gfx = Graphics.FromImage(Screenshot);
            gfx.CopyFromScreen(Screen.PrimaryScreen.Bounds.X, Screen.PrimaryScreen.Bounds.Y, 0, 0, Screen.PrimaryScreen.Bounds.Size, CopyPixelOperation.SourceCopy);
            


            for (int i = 0; i < Screen.PrimaryScreen.Bounds.Width; i++)
            {
                for (int j = 0; j < Screen.PrimaryScreen.Bounds.Height; j++)
                {

                    //pixel detection
                    pixelColor = Screenshot.GetPixel(i, j);
                    color = pixelColor.ToString();

                    //format ist: "Color [A=XXX, R=XXX, G=XXX, B=XXX]"
                    //"Color [A=XXX, R=" löschen
                    position = color.IndexOf(",");
                    color = color.Substring(position + 4);

                    //ende des R werts bestimmen
                    position = color.IndexOf(",");
                    R = color.Substring(0, position);

                    //"XXX, G=" löschen & ende bestimmen
                    color = color.Substring(position + 4);
                    position = color.IndexOf(",");
                    G = color.Substring(0, position);

                    //"XXX, B=" löschen & ende bestimmen
                    color = color.Substring(position + 4);
                    position = color.IndexOf("]");
                    B = color.Substring(0, position);


                    //rgb werte in hex werte ändern
                    tempInt = Convert.ToInt32(R);
                    R = String.Format("{0:X}", tempInt);
                    tempInt = Convert.ToInt32(G);
                    G = String.Format("{0:X}", tempInt);
                    tempInt = Convert.ToInt32(B);
                    B = String.Format("{0:X}", tempInt);

                    //bei zahlen unter 16 ist zbsp 10 = A und nicht 0A, daher 0 drankleben
                    if (R.Length == 1)
                        R = "0" + R;
                    if (G.Length == 1)
                        G = "0" + G;
                    if (B.Length == 1)
                        B = "0" + B;
                
                    hexArray[i,j] = R + G + B;

                }
            }

            sw.Stop();
            MessageBox.Show("Das Einlesen von " + (Screen.PrimaryScreen.Bounds.Width * Screen.PrimaryScreen.Bounds.Height)
                            + " Pixeln hat " + sw.ElapsedMilliseconds + "ms gedauert. Das sind " +
                            (Screen.PrimaryScreen.Bounds.Width * Screen.PrimaryScreen.Bounds.Height / sw.ElapsedMilliseconds)
                            + " Pixel/ms.");