dynamically generate image gallery in C#.net form application

I am working on Image gallery .In which I have dynamically create picturebox and label for giving image name.Now after getting load all images in to pictureboxes in a panel , issue is in arranging the picture boxes, only four in a row. After arranging the picture boxes when I am drag down the panel and again calling the button1_Click event the place of images getting destructed from them place.The images are loading on different location means it's getting over-write.please help me out.
Images links from where you can get exact idea
http://postimg.org/image/5tm5gzj87/
http://postimg.org/image/4sridmuuj/

here is my code.
please help me out..

CODE:

public partial class Form1 : Form
   {
       int photo_Count, a;
       PictureBox[] pb;
       private string[] imgName;
       public static string ImageToShow;
       string _directoryName = @"./Snapshot";
       Image im;
       Bitmap bm;
       // System.IO.Directory mydir;
       System.IO.DirectoryInfo dirinfo;
       public Form1()
       {
           InitializeComponent();
           panel1.Top = (this.ClientSize.Height - panel1.Height) / 2;
           panel1.Left = (this.ClientSize.Width - panel1.Width) / 2;
       }

       private void AddControls(int Count)
       {
           pb = new System.Windows.Forms.PictureBox[Count]; // assign number array

           for (int i = 0; i < Count; i++)
           {
               pb[i] = new System.Windows.Forms.PictureBox(); // Initialize one variable
           }
           // When call this function you determine number of controls
       }

       // The Event to click the image
       private void ClickImage(Object sender, System.EventArgs e)
       {


           // On Click: load (ImageToShow) with (Tag) of the image

           ImageToShow = ((System.Windows.Forms.PictureBox)sender).Tag.ToString();

           //PictureBox picBox = (PictureBox)(sender);
           //picBox.BorderStyle = BorderStyle.Fixed3D;

       }
       private Image GetCopyImage(string path)
       {
           a = 1;
           using (im = Image.FromFile(path))
           {

               bm = new Bitmap(im);
               return bm;

           }
       }

       private void button1_Click(object sender, EventArgs e)
       {


           if (Directory.Exists(_directoryName))
           {
               imgName = Directory.GetFiles(Application.StartupPath + @"\Snapshot");
               dirinfo = new System.IO.DirectoryInfo(_directoryName);
               photo_Count = dirinfo.GetFiles("*jpg").Count();

               if (photo_Count != 0)
               {


                   AddControls(photo_Count);
                   int xpos = 5;
                   int ypos = 5;

                   //      MessageBox.Show("Total No of traked images in the directory are : " + photo_Count);

                   for (int i = 0; i < photo_Count; ++i)
                   {
                       Label name = new Label();
                       //*******************Load tracked Images from the folder*********************//

                       im = GetCopyImage(imgName[i]);
                       pb[i].Image = im;

                       if (xpos > 920)
                       {
                           xpos = 5; // leave eight pixels at Left
                           ypos = ypos + 240;  // height of image + 220
                       }
                       pb[i].Left = xpos;
                       pb[i].Top = ypos;
                       pb[i].Size = new Size(300, 220);
                       pb[i].BorderStyle = BorderStyle.None;

                       pb[i].SizeMode = PictureBoxSizeMode.Zoom;
                       pb[i].BackgroundImageLayout = ImageLayout.Tile;
                       pb[i].Cursor = System.Windows.Forms.Cursors.Hand;
                       panel1.Controls.Add(pb[i]);
                       pb[i].BringToFront();
                       pb[i].Tag = imgName[i];
                       pb[i].Click += new System.EventHandler(ClickImage);

                       var filenNme = Path.GetFileName(imgName[i]);
                       name.Text = filenNme.ToString();
                       name.Size = new Size(300, 30);
                       name.Left = xpos;
                       name.Top = ypos + 220;
                       name.Tag = imgName[i];
                       panel1.Controls.Add(name);
                       xpos = xpos + 305;

                   }
               }
               else
               {
                   MessageBox.Show("There is no tracked image in directory...!!!", "Information", MessageBoxButtons.OK, MessageBoxIcon.Information);
               }
           }
           else
           {
               if (MessageBox.Show("There is no directory for Tracked Images...!!!", "Information", MessageBoxButtons.YesNo, MessageBoxIcon.Information) == DialogResult.Yes) ;
               {
                   System.IO.Directory.CreateDirectory(_directoryName);

               }

           }
       }

       private void btnDELETE_Click(object sender, EventArgs e)
       {
           File.Delete(ImageToShow);
           //button1.PerformClick();
           MessageBox.Show("The image is deleted successfully...!!!", "Information",  MessageBoxButtons.OK, MessageBoxIcon.Information);

       }

Tags: C# (C# 4.0)