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From: Tony Johansson on 14 Jun 2010 03:57
Hello!

Below I have a method Form1_Paint that does some drawing on the screen.
Now to my question what is the point to have a method AddRectangle in class
GraphicsPath when
class Graphics have the method DrawRectangle. In my example rows marked
with 1 and 2 in the code draw
identically rectangle. So why have methods in classes that is not necessary
because in this case we already have
DrawRectangle in class Graphics.

private void Form1_Paint(object sender, PaintEventArgs e)
{
Graphics g = e.Graphics;
Pen p = new Pen(Color.Red, 7);
GraphicsPath graphPath = new GraphicsPath();
Point myPoint = new Point(1, 1);
Size mySize = new Size(100, 200);

1 graphPath.AddRectangle(new Rectangle(myPoint, mySize));
1 g.DrawPath(p, graphPath);

2 g.DrawRectangle(p, new Rectangle(myPoint, mySize));
}

//Tony



From: Alberto Poblacion on 14 Jun 2010 05:09
"Tony Johansson" <johansson.andersson(a)telia.com> wrote in message
news:OdC89c5CLHA.5476(a)TK2MSFTNGP06.phx.gbl...
> Now to my question what is the point to have a method AddRectangle in
> class
> GraphicsPath when
> class Graphics have the method DrawRectangle.

GraphicsPath is not necessarily used for drawing. For example, you can
use a GraphicsPath for creating a form with a non-standard shape. In such a
case, it would make sense that the shape of the form contains a rectangle,
which would be achieved by means of AddRectangle, but the DrawRectangle
would not be useful since we would not be drawing anything.

Conversely, you may draw on a form without ever using a GraphicsPath,
which is where DrawRectangle is useful.


From: Peter Duniho on 14 Jun 2010 11:12
Alberto Poblacion wrote:
> "Tony Johansson" <johansson.andersson(a)telia.com> wrote in message
> news:OdC89c5CLHA.5476(a)TK2MSFTNGP06.phx.gbl...
>> Now to my question what is the point to have a method AddRectangle in
>> class
>> GraphicsPath when
>> class Graphics have the method DrawRectangle.
>
> GraphicsPath is not necessarily used for drawing. For example, you
> can use a GraphicsPath for creating a form with a non-standard shape. [...]

And even when it is, it would generally be used to cache drawing
commands for repeated use later, rather than being created from scratch
each time you need to draw the control.

There's not really any point in creating a new GraphicsPath from scratch
each time the Paint event handler is called, if all you're doing with
the GraphicsPath is drawing it. But that doesn't mean that the
GraphicsPath class isn't useful. It just means it's useful for other
things.

Pete
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