How can I convert the mouse cursor coordinates when click on pictureBox are to the screen relative mouse cursor coordinates?

Question

In my program I added this code so when I move my mouse all over the screen I will get the mouse cursor coordinates in real time:

Form1 Load:

private void Form1_Load(object sender, EventArgs e)
        {
            System.Windows.Forms.Timer t1 = new System.Windows.Forms.Timer();
            t1.Interval = 50;
            t1.Tick += new EventHandler(timer1_Tick);
            t1.Enabled = true;;
        }

Then the method that get the mouse position:

public static Point GetMousePosition()
        {
            var position = System.Windows.Forms.Cursor.Position;
            return new Point(position.X, position.Y);
        }

Then the timer1 tick event:

private void timer1_Tick(object sender, EventArgs e)
        {
            label1.Text = string.Format("X={0}, Y={1}", GetMousePosition().X, GetMousePosition().Y);
        }

Then I ran some application and moved the mouse over a specific location on the screen where the application window is and I found this coordinates:

358, 913

Now I have in my program a listBox with items each item present application screenshot. And if I click on the pictureBox for example in this case on the BATTLEFIELD 3 area I get the mouse cursor coordinates according to the pictureBox area.

So I did:

    Point screenCoordinates;
    Point pictureBoxSnapCoordinates;
    private void pictureBoxSnap_MouseDown(object sender, MouseEventArgs e)
    {
        screenCoordinates = pictureBoxSnap.PointToScreen(e.Location);
        pictureBoxSnapCoordinates = e.Location;
    }

Now when I click in the pictureBox at the same location as I found the coordinates 358, 913 but on the pictureBox so the results are:

screenCoordinates 435, 724

pictureBoxSnapCoordinates 23,423

The screenCoordinates isn't the same coordinates as I found with the mouse move 358, 913 it's not even close. There is a big difference between 358,913 and 437,724

Answer 1

e.Location is relative to the Control's top left corner. If you want to use e.Location to get the screen coordinates, then you have to first do pictureBoxSnap.PointToScreen(Point.Empty); and then offset by the e.Location .

Also, Cursor.Position returns a Point object, so making a new Point(...) is point less.

Answer 2

I must add, if you are dealing with images, and you need to interact with mouse, and do any task related with offset, scroll, etc, I recommend you that library, it is open source and have a lot of examples and methods that will help you

https://github.com/cyotek/Cyotek.Windows.Forms.ImageBox