Controlling the visibility of a Bitmap in .NET

Posted by ET on Stack Overflow See other posts from Stack Overflow or by ET
Published on 2010-04-17T21:55:29Z Indexed on 2010/04/17 22:13 UTC
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Hi everyone,

I am trying to create this simple application in c#: when the user double clicks on specific location in the form, a little circle will be drawn. By one click, if the current location is marked by a circle - the circle will be removed.

I am trying to do this by simply register the MouseDoubleClick and MouseClick events, and to draw the circle from a .bmp file the following way:

private void MouseDoubleClick (object sender, MouseEventArgs e)
{
    Graphics g = this.CreateGraphics();
    Bitmap myImage = (Bitmap)Bitmap.FromFile("Circle.bmp");
    g.DrawImage(myImage, e.X, e.Y);
}

My problem is that I dont know how to make the circle unvisible when the user clicks its location: I know how to check if the selected location contains a circle (by managing a list of all the locations containig circles...), but I dont know how exactly to delete it.

Another question: should I call the method this.CreateGraphics() everytime the user double-clicks a location, as I wrote in my code snippet, or should I call it once on initialization?

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