Rectangle/OnPaint Error in 2005

[=?Utf-8?B?Unlhbg==?=]

Why do I sometimes get this error; works fine most of the time:
Rectangle '{X=0,Y=0,Width =0,Height=0}' cannot have a width or height equal
to 0


void OnPaint(Object sender, PaintEventArgs e)
{
Graphics g = e.Graphics;
Rectangle r = ClientRectangle ;
LinearGradientB rush gradientBrush = new LinearGradientB rush(r,
Color.Navy, Color.Chocolate , LinearGradientM ode.ForwardDiag onal);
g.FillRectangle (gradientBrush, r);
}

[Peter Duniho]

Re: Rectangle/OnPaint Error in 2005

On Fri, 15 Aug 2008 17:47:12 -0700, Ryan <Ryan@discussio ns.microsoft.co m>
wrote:

Why do I sometimes get this error; works fine most of the time:
Rectangle '{X=0,Y=0,Width =0,Height=0}' cannot have a width or height
equal
to 0

When do you get the error? What line of code causes it? Can you post a
concise-but-complete code sample that reliably reproduces the problem?

AFAIK Graphics.FillRe ctangle has no limitation on using an empty
Rectangle. But as near as I can tell, LinearGradientB rush does. If you
pass it an empty rectangle, it will throw the exception you describe.

I don't know why you have a control instance that is empty when it tries
to paint itself, but the solution would be to either not let it have an
empty rectangle as its dimensions, or to check the rectangle in the
OnPaint() method and just not try to draw anything if the ClientRectangle
is empty.

Pete

[=?Utf-8?B?Unlhbg==?=]

Re: Rectangle/OnPaint Error in 2005

Peter,
The following line produces the error

LinearGradientB rush gradientBrush = new LinearGradientB rush(r, Color.Navy,
Color.Chocolate , LinearGradientM ode.ForwardDiag onal);

Complete code:

void OnPaint(Object sender, PaintEventArgs e)
{
Graphics g = e.Graphics;
Rectangle r = ClientRectangle ;
LinearGradientB rush gradientBrush = new LinearGradientB rush(r,
Color.Navy, Color.Chocolate , LinearGradientM ode.ForwardDiag onal);
g.FillRectangle (gradientBrush, r);
}

"Peter Duniho" wrote:

On Fri, 15 Aug 2008 17:47:12 -0700, Ryan <Ryan@discussio ns.microsoft.co m>
wrote:
>

Why do I sometimes get this error; works fine most of the time:
Rectangle '{X=0,Y=0,Width =0,Height=0}' cannot have a width or height
equal
to 0

>
When do you get the error? What line of code causes it? Can you post a
concise-but-complete code sample that reliably reproduces the problem?
>
AFAIK Graphics.FillRe ctangle has no limitation on using an empty
Rectangle. But as near as I can tell, LinearGradientB rush does. If you
pass it an empty rectangle, it will throw the exception you describe.
>
I don't know why you have a control instance that is empty when it tries
to paint itself, but the solution would be to either not let it have an
empty rectangle as its dimensions, or to check the rectangle in the
OnPaint() method and just not try to draw anything if the ClientRectangle
is empty.
>
Pete
>

[Peter Duniho]

Re: Rectangle/OnPaint Error in 2005

On Mon, 18 Aug 2008 07:24:04 -0700, Ryan <Ryan@discussio ns.microsoft.co m>
wrote:

Peter,
The following line produces the error
>
LinearGradientB rush gradientBrush = new LinearGradientB rush(r,
Color.Navy,
Color.Chocolate , LinearGradientM ode.ForwardDiag onal);

Well, since I'd already guessed that, I can't say that adds much.

Complete code:
>
void OnPaint(Object sender, PaintEventArgs e)
{
Graphics g = e.Graphics;
Rectangle r = ClientRectangle ;
LinearGradientB rush gradientBrush = new LinearGradientB rush(r,
Color.Navy, Color.Chocolate , LinearGradientM ode.ForwardDiag onal);
g.FillRectangle (gradientBrush, r);
}

That's not complete code. Please see Jon Skeet's discussion on the topic
of code samples, both complete and incomplete:

http://www.yoda.arachsys.com/csharp/complete.html

http://www.yoda.arachsys.com/csharp/incomplete.html

In any case, I believe that my previous reply included enough information
to help you fix the problem. Was there something about that reply you
didn't understand?

Pete

[=?Utf-8?B?Unlhbg==?=]

Re: Rectangle/OnPaint Error in 2005

Peter,
Your previous reply had given me enough information but I posted the OnPaint
method for your reference to get moer info.
The error is interminent and very difficult to reproduce; I have added the
follo
Thanks for your help.

I have modified the code as follows:
void OnPaint(Object sender, PaintEventArgs e)
{
Graphics g = e.Graphics;
Rectangle r = ClientRectangle ;
if (!r.IsEmpty)
{
LinearGradientB rush gradientBrush = new
LinearGradientB rush(r, Color.Navy, Color.Chocolate ,
LinearGradientM ode.ForwardDiag onal);
g.FillRectangle (gradientBrush, r);
}
}


"Peter Duniho" wrote:

On Mon, 18 Aug 2008 07:24:04 -0700, Ryan <Ryan@discussio ns.microsoft.co m>
wrote:
>

Peter,
The following line produces the error

LinearGradientB rush gradientBrush = new LinearGradientB rush(r,
Color.Navy,
Color.Chocolate , LinearGradientM ode.ForwardDiag onal);

>
Well, since I'd already guessed that, I can't say that adds much.
>

Complete code:

void OnPaint(Object sender, PaintEventArgs e)
{
Graphics g = e.Graphics;
Rectangle r = ClientRectangle ;
LinearGradientB rush gradientBrush = new LinearGradientB rush(r,
Color.Navy, Color.Chocolate , LinearGradientM ode.ForwardDiag onal);
g.FillRectangle (gradientBrush, r);
}

>
That's not complete code. Please see Jon Skeet's discussion on the topic
of code samples, both complete and incomplete:

http://www.yoda.arachsys.com/csharp/complete.html

http://www.yoda.arachsys.com/csharp/incomplete.html

>
In any case, I believe that my previous reply included enough information
to help you fix the problem. Was there something about that reply you
didn't understand?
>
Pete
>