1
You have to draw all image to one image for displaying them in single picturebox
That is bit complex you can use mutiple pictureboxes
In following code they are created dynamically according to need:
// For confirm visibility of all images set
this.AutoScroll = true;
string[] list = Directory.GetFiles(@"C:\pictures", "*.jpg");
PictureBox[] picturebox= new PictureBox[list.Length];
int y = 0;
for (int index = 0; index < picturebox.Length; index++)
{
this.Controls.Add(picturebox[index]);
// Following three lines set the images(picture boxes) locations
if(index % 3 == 0)
y = y + 150; // 3 images per rows, first image will be at (20,150)
picturebox[index].Location=new Point(index * 120 + 20, y);
picturebox[index ].Size = new Size(100,120);
picturebox[index].Image = Image.FromFile(list[index]);
}