Question

I was wondering, once i load an image into a windows form, is there a way for me to allow the user to drag the corners of that image and re-size it?

Currently, i know about the PictureBox.Scale method (but this is deprecated). I also know about PictureBox.Image.Size. Would this mean that each time they re-size i would need to use PictureBox.Image.Size? Also, how do i allow them to grab the image for re-sizing? I guess i’m thinking about paint and how it allows the user to select the image and then re-size it by dragging the corners…

I’m not looking for a full solution – just some pointers in the right direction (Pseudo code or general description to help my thought process would be fine). I’m not quite sure how to approach this problem.

Here is my code so far:

        using (OpenFileDialog ofd = new OpenFileDialog())
        {
            ofd.Title = "Load Image";

            if (ofd.ShowDialog() == DialogResult.OK)
            {

                PictureBox pictureBox = new PictureBox();
                pictureBox.Image = new Bitmap(ofd.FileName);
                pictureBox.SizeMode = PictureBoxSizeMode.StretchImage;
                pictureBox.Size = pictureBox.Image.Size; 
                panelArea.Controls.Add(pictureBox); 

            }
        }

Answer 1

There is already a control in Winforms that can display a bitmap and supports resizing with the mouse: a form. You just need a little bit of surgery to turn it into a control:

        using (OpenFileDialog ofd = new OpenFileDialog()) {
            ofd.Title = "Load Image";

            if (ofd.ShowDialog() == DialogResult.OK) {
                var box = new Form();
                box.TopLevel = box.ControlBox = false;
                box.Visible = true;
                box.BackgroundImage = new Bitmap(ofd.FileName);
                panelArea.Controls.Add(box);
                box.Size = box.BackgroundImage.Size;
            }
        }