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Problem Getting PathGeometry Object from Path Programmatically?? RRS feed

  • Question

  • Hi,


    I'm trying to manipulate the a Path object programmatically, but have hit a stumbling block.

    I have have built a path programmatically before, and have been able to access these objects. However, I now have a need to create more complext shapes, and so am looking at creating the path in Expression Blend.

    I need a PathGeometry object to be able to access the PathFigure collection, and it's subsequent Segment objects.

    However, I find that the Data property of the path that I've created in expression blend doesn't expose a PathGeometry object as I'd expect. Instead it exposes a Geometry object, and this doesn't have the Figures property that I need.

    I've attached some code to illustrate what I'm doing. Not the cast to PathGeometry results in null.

    Any advice on what I can do here so I can manipulate the path parts here would be appreciated!

    XAML:

    <Path Margin="8,7.5,11.5,43.5" Fill="#FFFFFFFF" Stretch="Fill" Stroke="#FF000000" Data="M8,48 L47.5,7.5 87.5,47.5 79.5,55.5 47.5,23.5 15.5,55.5 z"/> 

    C# Bit:

    1foreach (UIElement element in designedResizable.LayoutRootProperty.Children) 
    2                    { 
    3                        Path path = element as Path; 
    4 
    5                        if (path != null
    6                        { 
    7                            Geometry geometry = path.Data; 
    8 
    9                            PathGeometry pathGeometry = geometry as PathGeometry; 
    10 
    11                            if (pathGeometry != null
    12                            { 
    13 
    14                                foreach (PathFigure figure in pathGeometry.Figures) 
    15                                { 
    16                                    // Adjust figures start 
    17 
    18                                    foreach (PathSegment segment in figure.Segments) 
    19                                    { 
    20                                        LineSegment lineSegment = segment as LineSegment; 
    21 
    22                                        if (lineSegment != null
    23                                        { 
    24                                            // Make line segment adjustments 
    25                                        } 
    26 
    27                                        ArcSegment arcSegment = segment as ArcSegment; 
    28 
    29                                        if (arcSegment != null
    30                                        { 
    31                                            // Make arc segment adjustments 
    32                                        } 
    33                                    } 
    34                                } 
    35                            } 
    36                        } 
    37                    } 
    38 




    Thursday, October 16, 2008 4:39 PM

Answers

  • Hi,

     

    Here is a small example to get the PathGeomerty from Path  in the code behind.

     

    In the code behind, First, we get the Geomerty of the Path, Next, we create a GeomertyValueSerializer instance to convert the Geometry to a string source.Then we invoke the PathFigureCollection’s Parse method to get the PathFigureCollection the instance of the Path.

     

    XAML code:

       <StackPanel >

            <Path Name="shape_path"

           Fill="#FFFFFFFF" Stretch="Fill"

           Stroke="#FF000000"

           Width="92.5" Height="57.617"

           Data="M137,122 C227,161 168.5,204.5 228.5,159.5" />

            <Button Width="50" Height="20" Click="btnFind" Content="Find" />

       </StackPanel>

     

    In the code behind:

     private void btnFind(object sender, RoutedEventArgs e)

            {

                if (shape_path != null)

                {

                    Geometry geomerty = shape_path.Data;

                    GeometryValueSerializer seralizer = new GeometryValueSerializer();

                    string value = seralizer.ConvertToString(geomerty, null);

     

                    PathFigureCollection figures = PathFigureCollection.Parse(value);

     

                    if (figures != null)

                    {

                        foreach (PathFigure figure in figures)

                        {

                            foreach (PathSegment segment in figure.Segments)

                            {

                                LineSegment lineSegment = segment as LineSegment;

                                if (lineSegment != null)

                                {

                                    // Make line segment adjustments

                                }

     

                                ArcSegment arcSegment = segment as ArcSegment;

                                if (arcSegment != null)

                                {

                                    // Make arc segment adjustments

                                }

                            }

                        }

                    }

                }

            }

     

     

    Help this helps.

     

    Thanks.


    Jim Zhou -MSFT
    Tuesday, October 21, 2008 8:16 AM