Zoom at PictureBox

Question

I have a Picture box at dock in parent container . And I want to create a button that it can zoom the picture in the PictureBox and unzoom it !!! have anyone any idea or a tutorial that it could help me ?

Hemant Srivastava · Answer

Add a TrackBar and On TrackBarScroll event use the follwoing code: private void trackBar1_Scroll(object sender, EventArgs e) { double zoomlevel = 1+ trackBar1.Value * 0.1; ZoomIN(zoomlevel); } private void ZoomIN(double zoomLevel) { System.Drawing.Rectangle screenSize = new System.Drawing.Rectangle(); screenSize.Width = SystemInformation.VirtualScreen.Width; screenSize.Height = SystemInformation.VirtualScreen.Height; //int zoomFactor = 10; Image img = pictureBox1.Image; Bitmap bitMapImg = new Bitmap(img); if (bitMapImg.Width { Size newSize = new Size((int)(bitMapImg.Width * zoomLevel), (int)(bitMapImg.Height * zoomLevel)); Bitmap bmp = new Bitmap(bitMapImg, newSize); pictureBox1.Image = (Image)bmp; } }

Hemant Srivastava · Answer

Find the attached sample project for zoom in and zoom out using track bar.

Nikos Rak · Answer

Yes , I mean gradually zooming out using track bar ! how ?

Hemant Srivastava · Answer

You mean, you want gradually zooming out using track bar ? If yes, you could do it. I proposed the "Preserving" solution for Unzoom thinking that you mean 'Unzoom' is removing zoom completly at once.

Nikos Rak · Answer

I can't do it with the TrackBar ?

Hemant Srivastava · Answer

It it helped you, please mark the answer accepted.

Hemant Srivastava · Answer

To undo zooming, you can preserve size (Height and Width) of Image at the very first in some variable and when you press the UnZoom button, you may load the image with the same preserved dimensions into the picture box.

Nikos Rak · Answer

First you are awesome :D and second what about unzoom ?

Nikos Rak · Answer

it needs code the trackbar ? ,sure yes but what code ,

Hemant Srivastava · Answer

If you want to do zoom gradually, I think you need to do it by using TrackBar (Slider) instead of button and map the TrackBar value into into a range in which you need zooming.

Nikos Rak · Answer

this zoom it just zoom alot the picture I need to zoom at stages .. I mean if zoom = 1.0 to be 1.1 after 1.1 to 1.2 etc etc ... and for unzoom if zoom = 1.2 to 1.1

Hemant Srivastava · Answer

You can zoom in this way: private void btn_ZoomIN_Click(object sender, EventArgs e) { System.Drawing.Rectangle screenSize = new System.Drawing.Rectangle(); screenSize.Width = SystemInformation.VirtualScreen.Width; screenSize.Height = SystemInformation.VirtualScreen.Height; int zoomFactor = 10; Image img = pictureBox1.Image; Bitmap bitMapImg = new Bitmap(img); if (bitMapImg.Width { Size newSize = new Size((int)(bitMapImg.Width * zoomFactor), (int)(bitMapImg.Height * zoomFactor)); Bitmap bmp = new Bitmap(bitMapImg, newSize); pictureBox1.Image = (Image)bmp; } } Note: But to see zooming, you need to add scrollbar on your picture Box. To get scroll bar on Picture Box: Place your PictureBox into Panel. Set 'SizeMode' property of PictureBox to "AutoSize"