move an image inside a picturebox Border

Question

I used the following code to move the image inside the image box, but it may come out of the frame when crawling with the mouse right or left. I want the image not to leave the frame of the image.

my code The image is moving but is outside the frame designated for the image.

  private void pictureBox1_MouseMove(object sender, MouseEventArgs e)  
        {  
            
                if (pictureBox1.Image != null)  
                {  
                    if ((e.Button == 0))  
                    {  
                          
  
                    }  
                    else  
                    {  
  
                        pictureBox1.Left = (pictureBox1.Left  
                              + (e.X - mousePosX));  
                        pictureBox1.Top = (pictureBox1.Top  
                                    + (e.Y - mousePosY));  
                   
                }  
  
                //}  
  
  
            }  
        }  

Answer 1

Try the following custom PictureBox

using System;  
using System.Drawing;  
using System.Windows.Forms;  
  
namespace PictureBoxCustomCore  
{  
    public class ProPictureBox : PictureBox  
    {  
        private Point? _clickedPoint;  
        private ProTransformation _transformation;  
  
        public ProTransformation Transformation  
        {  
            set  
            {  
                _transformation = FixTranslation(value);  
                Invalidate();  
            }  
            get => _transformation;  
        }  
  
        public ProPictureBox()  
        {  
            _transformation = new ProTransformation(new Point(100, 0), .5f);  
            MouseDown += OnMouseDown;  
            MouseMove += OnMouseMove;  
            MouseUp += OnMouseUp;  
            MouseWheel += OnMouseWheel;  
            Resize += OnResize;  
        }  
  
        private ProTransformation FixTranslation(ProTransformation value)  
        {  
  
            var maxScale = Math.Max((double) Image.Width / ClientRectangle.Width, (double) Image.Height / ClientRectangle.Height);  
            if (value.Scale > maxScale)  
            {  
                value = value.SetScale(maxScale);  
            }  
  
            if (value.Scale < 0.3)  
            {  
                value = value.SetScale(0.3);  
            }  
  
            var rectSize = value.ConvertToIm(ClientRectangle.Size);  
            var max = new Size(Image.Width - rectSize.Width, Image.Height - rectSize.Height);  
  
            value = value.SetTranslate((new Point(Math.Min(value.Translation.X, max.Width), Math.Min(value.Translation.Y, max.Height))));  
            if (value.Translation.X < 0 || value.Translation.Y < 0)  
            {  
                value = value.SetTranslate(new Point(Math.Max(value.Translation.X, 0), Math.Max(value.Translation.Y, 0)));  
            }  
  
            return value;  
        }  
  
        private void OnResize(object sender, EventArgs eventArgs)  
        {  
            if (Image == null)  
            {  
                return;  
            }  
  
            Transformation = Transformation;  
        }  
  
        private void OnMouseWheel(object sender, MouseEventArgs e)  
        {  
            if (Image == null)  
            {  
                return;  
            }  
  
            var transformation = _transformation;  
            var pos1 = transformation.ConvertToIm(e.Location);  
  
            transformation = e.Delta > 0 ? transformation.SetScale(Transformation.Scale / 1.25) : transformation.SetScale(Transformation.Scale * 1.25);  
  
            var pos2 = transformation.ConvertToIm(e.Location);  
            transformation = transformation.AddTranslate(pos1 - (Size) pos2);  
            Transformation = transformation;  
        }  
  
        private void OnMouseUp(object sender, MouseEventArgs mouseEventArgs)  
        {  
            _clickedPoint = null;  
        }  
  
        private void OnMouseMove(object sender, MouseEventArgs e)  
        {  
            if (_clickedPoint == null)  
            {  
                return;  
            }  
  
            var p = _transformation.ConvertToIm((Size) e.Location);  
            Transformation = _transformation.SetTranslate(_clickedPoint.Value - p);  
        }  
  
        private void OnMouseDown(object sender, MouseEventArgs e)  
        {  
            if (Image == null)  
            {  
                return;  
            }  
  
            Focus();  
  
            _clickedPoint = _transformation.ConvertToIm(e.Location);  
        }  
  
        protected override void OnPaint(PaintEventArgs e)  
        {  
            if (Image == null)  
            {  
                return;  
            }  
  
            var imRect = Transformation.ConvertToIm(ClientRectangle);  
            e.Graphics.DrawImage(Image, ClientRectangle, imRect, GraphicsUnit.Pixel);  
        }  
  
        public void DecideInitialTransformation()  
        {  
            Transformation = new ProTransformation(Point.Empty, int.MaxValue);  
        }  
    }  
}  

Answer 2

Try something like this (inside the else block):

Rectangle r = pictureBox1.Bounds;

r.X = r.X + ( e.X - mousePosX );
r.Y = r.Y + ( e.Y - mousePosY );

if( r.Right > pictureBox1.Parent.ClientRectangle.Right )
    r.X = pictureBox1.Parent.ClientRectangle.Right - r.Width;

if( r.Bottom > pictureBox1.Parent.ClientRectangle.Bottom )
    r.Y = pictureBox1.Parent.ClientRectangle.Bottom - r.Height;

if( r.X < 0 )
    r.X = 0;

if( r.Y < 0 )
    r.Y = 0;

pictureBox1.Location = r.Location;