Problem with StrokeDashArray (getting dotted lines)

07-31-2008 9:16 AM |

Hi, I'm trying to draw a rectangle with a dotted line. Should be easy?

<Rectangle Stroke="#FFFFC0CB" StrokeThickness="1" StrokeDashArray="1,1"/>

According to the docs, that should draw 1 pixel on, 1 pixel gap, 1 pixel on, etc...

But for some reason, it draws a solid line all the way around the rectangle.

Is this intentional? How can I get a simple dotted line around my shape?

Thanks,

Mark

Re: Problem with StrokeDashArray (getting dotted lines)

07-31-2008 12:28 PM |

For what reasons?

Maybe you can try a larger one

 <Rectangle Width="100" Height="100" Stroke="Black" StrokeDashArray="10, 2"/>

Re: Problem with StrokeDashArray (getting dotted lines)

07-31-2008 12:46 PM |

 If you change your StrokeThickness to a value that is greater than 1 (like 1.1 - 2.0), you will see that the dotted line starts to appear.  I'm not sure why it doesn't appear at a StrokeThickness of 1.

Re: Problem with StrokeDashArray (getting dotted lines)

07-31-2008 5:56 PM |

Yes I had noticed that, I tried 1.1 as the thickness and it worked ok (except it didn't look right due to anti-aliasing)

Seems like it's a bug then.

Re: Problem with StrokeDashArray (getting dotted lines)

08-04-2008 5:41 AM |

Hello, this does look like a bug. Thanks for reporting it. I'll notify our product team.

Re: Re: Problem with StrokeDashArray (getting dotted lines)

08-05-2008 12:03 AM |

Hi, I got the response from our product team. It's by design. This behavior is once again caused by anti-aliasing. In WPF, you can turn off anti-aliasing on non-text elements by setting RenderOptions.EdgeMode Attached Property to Aliased. But currently there's no way to turn off anti-aliasing in Silverlight. Maybe in the future we'll support this. But I can't give you any promise at this time...

Re: Re: Problem with StrokeDashArray (getting dotted lines)

08-05-2008 3:46 AM |

 Right ok, thanks for looking into that for me. It seems like there will be no easy way to get a simple dotted line in the near future then?

Thanks,

Mark

Re: Re: Re: Problem with StrokeDashArray (getting dotted lines)

08-05-2008 3:53 AM |

But if you set StrokeThickness to 1.001, it will work fine, right?

Re: Re: Re: Problem with StrokeDashArray (getting dotted lines)

08-05-2008 6:29 AM |

No, it works on the vertical sides of a rectangle, but not on the horizontal sides of a rectangle. It ends up looking like:

----------
.        .
.        .
.        .
----------

(i.e. solid line across top + bottom, dotted line up sides) 

Code:

<Grid>
        <Rectangle Width="200" Height="200" Fill="LightBlue" Stroke="Salmon" StrokeThickness="1.0001" StrokeDashArray="1, 1" HorizontalAlignment="Center" VerticalAlignment="Center"/>
    </Grid>