Question

I have a problem:

I have 3 picture boxes with 3 different images as in Image

what can i set to pictureBox3 so both images look same…..

EDITED:
I want to move pictureBox3 on pictureBox2,

So there is no Option to merge them to single image

Answer 1

I’ll add another example that according to the updated requirement allows for moving image3.
To get it working, put an image with transparency in Resources\transp.png
This uses the same image for all three images, but you can simply replace transparentImg for image1 and image2 to suitable images.

Once the demo is started the middle image can be dragged-dropped around the form.

public partial class Form1 : Form
{
    private readonly Image transparentImg; // The transparent image
    private bool isMoving = false;         // true while dragging the image
    private Point movingPicturePosition = new Point(80, 20);   // the position of the moving image
    private Point offset;   // mouse position inside the moving image while dragging
    public Form1()
    {
        InitializeComponent();

        // 
        // pictureBox1
        // 
        this.pictureBox1.Location = new System.Drawing.Point(0, 0);
        this.pictureBox1.Name = "pictureBox1";
        this.pictureBox1.Size = new System.Drawing.Size(231, 235);
        this.pictureBox1.TabIndex = 0;
        this.pictureBox1.TabStop = false;
        this.pictureBox1.Paint += new System.Windows.Forms.PaintEventHandler(this.pictureBox1_Paint);
        this.pictureBox1.MouseDown += new System.Windows.Forms.MouseEventHandler(this.pictureBox1_MouseDown);
        this.pictureBox1.MouseMove += new System.Windows.Forms.MouseEventHandler(this.pictureBox1_MouseMove);
        this.pictureBox1.MouseUp += new System.Windows.Forms.MouseEventHandler(this.pictureBox1_MouseUp);
        this.Controls.Add(this.pictureBox1);
        transparentImg = Image.FromFile("..\\..\\Resources\\transp.png");
    }

    private void pictureBox1_Paint(object sender, PaintEventArgs e)
    {
        var g = e.Graphics;
        g.DrawImageUnscaled(transparentImg, new Point(20, 20));      // image1
        g.DrawImageUnscaled(transparentImg, new Point(140, 20));     // image2
        g.DrawImageUnscaled(transparentImg, movingPicturePosition);  // image3
    }

    private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
    {
        var r = new Rectangle(movingPicturePosition, transparentImg.Size);
        if (r.Contains(e.Location))
        {
            isMoving = true;
            offset = new Point(movingPicturePosition.X - e.X, movingPicturePosition.Y - e.Y);
        }
    }

    private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
    {
        if (isMoving)
        {
            movingPicturePosition = e.Location;
            movingPicturePosition.Offset(offset);
            pictureBox1.Invalidate();
        }
    }

    private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
    {
        isMoving = false;
    }
}