Immer die pixel-Farbe von PictureBox zeichnen von Linien, die nach

Verwenden Bob Powell ' s Eye Dropper, hier ist der code:

using System;
using System.Runtime.InteropServices;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;


namespace pixelcolor
{
  ///<summary>
  ///Summary description for Form1.
  ///</summary>
  public class Form1 : System.Windows.Forms.Form
  {


    [DllImport("Gdi32.dll")]
    public static extern int GetPixel(
    System.IntPtr hdc,    //handle to DC
    int nXPos,  //x-coordinate of pixel
    int nYPos   //y-coordinate of pixel
    );

    [DllImport("User32.dll")]
    public static extern IntPtr GetDC(IntPtr wnd);

    [DllImport("User32.dll")]
    public static extern void ReleaseDC(IntPtr dc);


    private System.Windows.Forms.Panel panel1;
    private System.Timers.Timer timer1;

    ///<summary>
    ///Required designer variable.
    ///</summary>
    private System.ComponentModel.Container components = null;

    public Form1()
    {
      //
      //Required for Windows Form Designer support
      //
      InitializeComponent();
      this.SetStyle(ControlStyles.ResizeRedraw,true);
    }

    ///<summary>
    ///Clean up any resources being used.
    ///</summary>
    protected override void Dispose( bool disposing )
    {
      if( disposing )
      {
        if (components != null)
        {
          components.Dispose();
        }
      }
      base.Dispose( disposing );
    }

    #region Windows Form Designer generated code
    ///<summary>
    ///Required method for Designer support - do not modify
    ///the contents of this method with the code editor.
    ///</summary>
    private void InitializeComponent()
    {
      this.panel1 = new System.Windows.Forms.Panel();
      this.timer1 = new System.Timers.Timer();
      ((System.ComponentModel.ISupportInitialize)(this.timer1)).BeginInit();
      this.SuspendLayout();
      //
      //panel1
      //
      this.panel1.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D;
      this.panel1.Location = new System.Drawing.Point(216, 8);
      this.panel1.Name = "panel1";
      this.panel1.Size = new System.Drawing.Size(64, 56);
      this.panel1.TabIndex = 0;
      //
      //timer1
      //
      this.timer1.Enabled = true;
      this.timer1.SynchronizingObject = this;
      this.timer1.Elapsed += new System.Timers.ElapsedEventHandler(this.timer1_Elapsed);
      //
      //Form1
      //
      this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
      this.BackColor = System.Drawing.Color.White;
      this.ClientSize = new System.Drawing.Size(292, 273);
      this.Controls.Add(this.panel1);
      this.Name = "Form1";
      this.Text = "Form1";
      this.Paint += new System.Windows.Forms.PaintEventHandler(this.Form1_Paint);
      ((System.ComponentModel.ISupportInitialize)(this.timer1)).EndInit();
      this.ResumeLayout(false);

    }
    #endregion

    ///<summary>
    ///The main entry point for the application.
    ///</summary>
    [STAThread]
    static void Main()
    {
      Application.Run(new Form1());
    }

    private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
    {
      Random r=new Random(1);

      for(int x=0;x<100;x++)
      {
        SolidBrush b=new SolidBrush(Color.FromArgb(r.Next(255),r.Next(255),r.Next(255)));
        e.Graphics.FillRectangle(b,r.Next(this.ClientSize.Width),r.Next(this.ClientSize.Height),r.Next(100),r.Next(100));
      }
    }

    private void timer1_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
    {
      Point p=Control.MousePosition;
      IntPtr dc=GetDC(IntPtr.Zero);
      this.panel1.BackColor=ColorTranslator.FromWin32(GetPixel(dc,p.X,p.Y));
      ReleaseDC(dc);
    }
  }
}

Wenn Sie wollten, probieren Sie die Farben in einer PictureBox oder in Ihrer eigenen form, dann müssen Sie einfach zu erhalten, die DC für das Objekt. Dies kann erreicht werden, mit CreateGraphics, Grafiken.GetHdc und Grafiken.ReleaseHdc. Die Auflistung unten zeigt ein MouseMove-handler kann verwendet werden, um die pixel-Farbe von der form.

protected override void OnMouseMove(MouseEventArgs e)
{
  Graphics g=this.CreateGraphics();
  IntPtr myDC=g.GetHdc();
  Color c=ColorTranslator.FromWin32(GetPixel(myDC,e.X,e.Y));
  g.ReleaseHdc(myDC);

  this.panel1.BackColor=c;
}