Csharp/CSharp Tutorial/GUI Windows Forms/ImageList

Add Image in an ImageList to a Button

using System;
using System.Drawing;
using System.Windows.Forms;
using System.Collections;
public class ImageLists : Form
{
  ImageList imgList;
  Label lbl;
  LinkLabel lnk;
  Button btn;
  public ImageLists()
  {
       Size = new Size(300,300);
    imgList = new ImageList();
    Image img;
    String[] arFiles = {"1.ico","2.ico","3.ico"};

    for (int i = 0; i < arFiles.Length; i++)
    {
      img = Image.FromFile(arFiles[i]);
      imgList.Images.Add(img);
    }
    imgList.ImageSize = new Size(32, 32);

    lbl = new Label();
       lbl.Parent = this;
       lbl.Text = "Label";
       lbl.Location = new Point(0,0);
       lbl.Size = new Size(lbl.PreferredWidth + imgList.ImageSize.Width, 
      imgList.ImageSize.Height + 10);
       lbl.BorderStyle = BorderStyle.Fixed3D;
    lbl.ImageList = imgList;
    lbl.ImageIndex = 0;
    lbl.ImageAlign = ContentAlignment.MiddleRight;
       int yDelta = lbl.Height + 10;
     
       lnk = new LinkLabel();
       lnk.Parent = this;
       lnk.Text = "LinkLabel";
       lnk.Size = new Size(lnk.PreferredWidth + imgList.ImageSize.Width, 
      imgList.ImageSize.Height + 10);
       lnk.Location = new Point(0, yDelta);
    lnk.ImageList = imgList;
    lnk.ImageIndex = 0;
    lnk.ImageAlign = ContentAlignment.MiddleRight;
    btn = new Button();
    btn.Parent = this;
    btn.ImageList = imgList;
    btn.ImageIndex = imgList.Images.Count - 1;
    btn.Location = new Point(0, 2 * yDelta);
    btn.Size = new Size(3 * imgList.ImageSize.Width, 
              2 * imgList.ImageSize.Height);

    lbl.ImageIndex = 1;
    lnk.ImageIndex = 0;
    btn.ImageIndex = 2;
  }
  static void Main() 
  {
      Application.Run(new ImageLists());
  }
}

Replace an Image with another Image in an ImageList

using System;
using System.Drawing;
using System.Windows.Forms;
using System.Collections;
public class ImageListImageReplace : Form
{
  ImageList imgList;
  Button btn;
  public ImageListImageReplace()
  {
       Size = new Size(300,300);
    imgList = new ImageList();
    Image img;
    String[] arFiles = {"1.ico","2.ico","3.ico"};

    for (int i = 0; i < arFiles.Length; i++)
    {
      img = Image.FromFile(arFiles[i]);
      imgList.Images.Add(img);
    }
    imgList.ImageSize = new Size(32, 32);
    img = Image.FromFile("4.ico");
    imgList.Images[imgList.Images.Count - 1] = img;
    btn = new Button();
    btn.Parent = this;
    btn.ImageList = imgList;
    btn.ImageIndex = imgList.Images.Count - 1;
    btn.Location = new Point(0, 20);
    btn.Size = new Size(3 * imgList.ImageSize.Width, 
              2 * imgList.ImageSize.Height);
    btn.ImageIndex = 2;
  }
  static void Main() 
  {
      Application.Run(new ImageListImageReplace());
  }
}