how to get coordinates of image in picutre control -- dotnet drawing api

Pannu
10/11/2006 10:14:43 AM

I have a picturebox on my VB.NET form. The picturebox size mode is set to
stretched. I then load an image into that form and display it. As the user
moves the mouse over the form, I want to get and display (in the status bar)

the image coordinates of the mouse location. However, if I use the
picturebox's MouseMove event, I am getting the coordinates of the mouse
over
the PICTUREBOX, not the actual image underneath that (which is stretched).
i.e. if the actual image has a width of 2000, and I move the cursor over to
the right side of the stretched picturebox image, I am only getting a left
pixel value of around 1000 - because it is getting the mouse x:y
coordinates
of the picture box, not the actual image.

How can I accomplish this? There isn't any picturebox.image.mousemove event
that I can see. How can I translate what the picturebox gives me back to
the
coordinates of the actual image underneath it? Or have I got to go about
this differently?

Bob Powell [MVP]
10/11/2006 6:31:18 PM

Create a matrix that will resize the original image into the picturebox.

new Matrix((float)pb.Width / bitmap.Width,0,0,(float)pb.Height /
bitmap.Height,0,0);

Invert the matrix and use it to backtrack the mouse coords.

See how to backtrack the mouse in Windows Forms Tips and Tricks.

--
Bob Powell [MVP]
Visual C#, System.Drawing

Ramuseco Limited .NET consulting
http://www.ramuseco.com

Find great Windows Forms articles in Windows Forms Tips and Tricks
http://www.bobpowell.net/tipstricks.htm

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http://www.bobpowell.net/faqmain.htm

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dotnet drawing api : how to get coordinates of image in picutre control