mouse position (Cursor.Position)

Question

I have image 10*10 mult it in factor and loading the image to picturebox I have problem to select the mouse position when I clicking in everywhere over the image the point showing in the corner Upper-left what is the error??

have you tried doing a google search on the following `PointToClient(Cursor.Position)` http://stackoverflow.com/questions/8201286/get-cursor-position-with-respect-to-the-control-c-sharp also I would think that you would want to do this on the Mouse Click event hot the Image Click Event — MethodMan, Feb 15 '15 at 20:11
Us the `MouseClick` event instead. Its params have the coordinates (relative to the `PB.ClientSize`) — TaW, Feb 15 '15 at 21:08

TaW · Accepted Answer · 2015-02-16T21:13:25.793

0

To draw into a zoomed Image of a PictureBox this works fine for me:

float zoom = 7.5f;

public Form1()
{
    InitializeComponent();
    pb1.SizeMode = PictureBoxSizeMode.Zoom;
    pb1.ClientSize = new Size((int) (pb1.Image.Size.Width  * zoom), 
                              (int) (pb1.Image.Size.Height * zoom) );
}



private void pb1_MouseClick(object sender, MouseEventArgs e)
{
   int x = (int)Math.Round(e.X / zoom) ;
   int y = (int)Math.Round(e.Y / zoom) ;
   Bitmap bmp = (Bitmap) pb1.Image;
   bmp.SetPixel(x, y, Color.Red);
   pb1.Refresh();
}

Note: This works equally well if the PictureBox is sitting in an AutoScroll Panel.

enter image description here

edited Feb 16 '15 at 21:13

answered Feb 16 '15 at 20:18

TaW

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thank for answer ,please if you can see my update ,I have this error NullReferenceexception... – lena Feb 16 '15 at 20:40
Where do you get the exception? The code assumes the pb1.Image is loaded (from the start.) I don't see the zoom variable, but it wouldn't throw an exception but a compiler error.. – TaW Feb 16 '15 at 20:44
zoom variable I use it in my code but here not :( but the same error NullReferenceexception.... – lena Feb 16 '15 at 20:52
Where?????????? Note: you can set the `pb1.ClientSize` only __after__ setting the `Image` !! (Also note the improved calculation!) – TaW Feb 16 '15 at 20:55
here and same the error pb1.ClientSize = new Size((int) (pb1.Image.Size.Width * zoom), (int) (pb1.Image.Size.Height * zoom) ); ,I'm work on the code in question – lena Feb 16 '15 at 21:18
I thought so. Make sure the size is __always and only__ set __after__ the Image is set! – TaW Feb 16 '15 at 21:19
The solution is very simple: __Move__ the line in question to the spot in the `button1_Click` I have marked as `//***` - My test program sets the image in the designer; I should have noticed that you use a dialog to set it. Sorry! – TaW Feb 16 '15 at 21:29

mouse position (Cursor.Position)

1 Answers1