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WPF User Control Polyline Size Wrong

I have created a custom user control for WPF use with VB.net for the code behind. Essentially, it is a polyline that snaps to connect other custom controls. The Polyline is created via code at runtime. It works great vertically and if it has both width and height. However if it is horizontal or flat, it distorts. The thicker the line, the worse it distorts. It distorts on both ends with neither beginning or ending in the right location.

Any ideas on how to fix? It looks like a stretch issue but it doesn't stretch completely.

Bob Learned

Can you give us a small bit of code to highlight the problem, please?

Tesla428

ASKER

Bob Learned

What does the XAML/code look like?

Tesla428

ASKER

Public Class Pipe
    Private mLine As New Polyline
    Private mOutline As New Polyline

    Public Sub New(ByVal First As Point, ByVal Last As Point)
        InitializeComponent()

        With mOutline
            .Stroke = Brushes.Red
            .HorizontalAlignment = HorizontalAlignment.Left
            .VerticalAlignment = VerticalAlignment.Top
            .StrokeThickness = 5
            .Stretch = Stretch.None
        End With

        With mLine
            .Stroke = Brushes.Black
            .HorizontalAlignment = HorizontalAlignment.Left
            .VerticalAlignment = VerticalAlignment.Top
            .StrokeThickness = 2
            .Stretch = Stretch.None
         
            If First.X = Last.X Or First.Y = Last.Y Then
                .Points.Add(First)
                .Points.Add(Last)
            End If
            If First.X > Last.X Then
                .Points.Add(First)
                .Points.Add(New Point(First.X, Last.Y))
                .Points.Add(Last)
            End If
            If First.X < Last.X Then
                .Points.Add(First)
                .Points.Add(New Point(First.X, Last.Y))
                .Points.Add(Last)
            End If
        End With

        For Each SharePoint As Point In mLine.Points
            mOutline.Points.Add(SharePoint)
        Next

        grdPipe.Children.Add(mOutline)
        grdPipe.Children.Add(mLine)

    End Sub

End Class

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Polyline Class VB Code Behind

Tesla428

ASKER

<UserControl x:Class="Pipe"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             mc:Ignorable="d" 
             d:DesignHeight="300" d:DesignWidth="300" HorizontalContentAlignment="Left" VerticalContentAlignment="Top" HorizontalAlignment="Left" VerticalAlignment="Top">
    <Grid Name="grdPipe"></Grid> 
</UserControl>

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XAML For the Polylines

Tesla428

ASKER

<Window x:Class="MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Working" Height="362" Width="426" WindowState="Maximized">
    <Grid >
        <DockPanel x:Name="LayoutRoot"             LastChildFill="True">
            <StackPanel  Height="40" DockPanel.Dock="Top" Orientation="Horizontal" HorizontalAlignment="Left" VerticalAlignment="Top">
                <Slider x:Name="ZoomSlider"                Minimum="1" Value="1" Maximum="5" Height="26" VerticalAlignment="Top" HorizontalAlignment="Left" Width="85" Margin="10,10,0,0" />
                <TextBlock Height="22" Name="TextBlock1" Text="{Binding ElementName=ZoomSlider, Path=Value, StringFormat='Current Zoom: \{0:0.0\}x'}" Margin="12" />
                <CheckBox Content="Show GridLines" Height="16" Name="chkSnapLines" />
                
            </StackPanel>
            <ScrollViewer HorizontalScrollBarVisibility="Auto" VerticalScrollBarVisibility="Auto" HorizontalAlignment="Left" VerticalAlignment="Top">
                <Grid Name="grdMain" VerticalAlignment="Top" HorizontalAlignment="Left">
                    <Grid.LayoutTransform>
                        <ScaleTransform ScaleX="{Binding Path=Value, ElementName=ZoomSlider}"
                                        ScaleY="{Binding Path=Value,ElementName=ZoomSlider}" />
                    </Grid.LayoutTransform>
                   </Grid>
            </ScrollViewer>
        </DockPanel>

    </Grid>
</Window>

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XAML for Main Window

Bob Learned

I read your initial question, and I see the screen shot, but I still don't quite understand the issue. Are you having a problem with calculating the length of each line, with respect to the aspect ratio for the drawing surface?

Tesla428

ASKER

No, I need the lines to start and stop at a specific location. They do this correctly in every instance if they have a vertical component. However, if the are completely flat they stretch. Both the start point and end point are both affected and if the line is wider, it gets even worse.

Bob Learned

If you believe that this is a stretch issue, what is the width of the drawing surface, compared to it's height? If it is square, I wouldn't think that this would be a stretching issue.

Tesla428

ASKER

Are you able to replicate the issue? Even on a simple polyline? I am service packing visual studio and loading all available updates. I don't think it is video driver related.

ASKER CERTIFIED SOLUTION

Bob Learned

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Tesla428

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Tesla428

ASKER

I was able to locate it on my own.