Problem in drawing 1px line in InkPresenter with Stroke

3 replies. Latest Post by StefanWick on December 17, 2008.

(0)

Member

2 points

Problem in drawing 1px line in InkPresenter with Stroke

12-15-2008 3:54 AM |

I have a problem in drawing 1px line in InkPresenter using Stroke. I doubt there is something inperfect with its mechanism in rendering line. I have set my stroke's DrawingAttributes as follow:

            newStroke.DrawingAttributes.Color = Colors.Black;
            newStroke.DrawingAttributes.Height = 0.5; // 1 and 2 to be test
            newStroke.DrawingAttributes.Width = 0.5;
            newStroke.DrawingAttributes.OutlineColor = Colors.Transparent;

and I have get the result as follow picture compare with the Windows paint:

if not displayed, image url:Show image

As shown in picture, silverlight renders the 0.5px, 1px and 2px lines with no diffirence but color changing from lightgray to black. What I want is the line rendered in paint as lower part of the picture. How Can I solve this problem. The following is the code I written:

Page.xaml

<UserControl x:Class="HelloWorld.Page"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    Width="406" Height="404">
    <Grid x:Name="LayoutRoot" Background="Black">
        
        <InkPresenter x:Name="inkPresenter" Width="400" Height="400"
                      Background="White"
                      MouseLeftButtonDown="inkPresenter_MouseLeftButtonDown"
                       MouseLeftButtonUp="inkPresenter_MouseLeftButtonUp"
                       MouseMove="inkPresenter_MouseMove"/>
    </Grid>
</UserControl>

Page.xaml.cs

public partial class Page : UserControl
    {
        InkPresenter curInkPre = null;
        Cursor oldCursor = Cursors.Arrow;
        Stroke newStroke = null;
        public Page()
        {
            InitializeComponent();
            SetBoundary(inkPresenter);
        }

     
        private void inkPresenter_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            curInkPre = e.OriginalSource as InkPresenter;
            curInkPre.CaptureMouse();
            oldCursor = curInkPre.Cursor;
            curInkPre.Cursor = Cursors.Stylus;
            newStroke = new Stroke();
            newStroke.StylusPoints.Add(e.StylusDevice.GetStylusPoints(curInkPre));
            newStroke.DrawingAttributes.Color = Colors.Black;
            newStroke.DrawingAttributes.Height = 2;
            newStroke.DrawingAttributes.Width = 2;
            newStroke.DrawingAttributes.OutlineColor = Colors.Transparent;
            curInkPre.Strokes.Add(newStroke);
        }

        private void inkPresenter_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
        {
            newStroke = null;
            InkPresenter ink = e.OriginalSource as InkPresenter;
            ink.Cursor = oldCursor;
        }

        private void inkPresenter_MouseMove(object sender, MouseEventArgs e)
        {
            if (newStroke != null)
            {
                newStroke.StylusPoints.Add(e.StylusDevice.GetStylusPoints(curInkPre));
            }
        }
        private void SetBoundary(InkPresenter ink)
        {
            RectangleGeometry rectGeo = new RectangleGeometry();
            rectGeo.Rect = new Rect(0, 0, ink.ActualWidth, ink.ActualHeight);
            ink.Clip = rectGeo;
        }
    }