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Export UWP canvas to SVG

I'm trying to create an SVG file from some shape objects(path geometries, ellipses etc.) drawn on XAML canvas controls (the canvases are rendered on top of each other inside grid controls). It looks like Win2D can provide the classes to generate the SVG file, but I'm struggling to figure out how to populate the CanvasSvgDocument class with the shapes.
This is the only partial example I've found, but the answer seems to include a conversion to XML strings to load into the CanvasSvgDocument which seems like doing the same task twice (as SVG files are XML). Is anybody able to provide an example of how I might do this?
My current best guess of what the resulting code might look like is:
using Microsoft.Graphics.Canvas;
using Microsoft.Graphics.Canvas.Svg;
using Microsoft.Graphics.Canvas.UI.Xaml;
using System;
using System.Threading.Tasks;
using Windows.Storage.Streams;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Shapes;
namespace MyApp
{
public class ExportSVG
{
private CanvasSvgDocument SVG { get; } = new(new CanvasDevice());
public async Task SaveASync(IRandomAccessStream stream) => await SVG.SaveAsync(stream);
public void AddCanvases(UIElement element)
{
if (element is Grid grid)
{
foreach (UIElement child in grid.Children)
{
AddCanvases(child);
}
}
else if (element is Canvas canvas)
{
AddCanvas(canvas);
}
}
public void AddCanvas(Canvas canvas)
{
foreach (UIElement element in canvas.Children)
{
if (element is Path path)
{
if (path.Data is PathGeometry pathGeometry)
{
foreach (PathFigure pathFigure in pathGeometry.Figures)
{
// Add path to SVG
}
}
else if (path.Data is EllipseGeometry ellipseGeometry)
{
// Add ellipse to SVG
}
}
else if (element is TextBlock textBlock)
{
// add text to SVG
}
}
}
}
}

You could use CanvasGeometry.CreateInk convert the ink strokes into geometry and use the relevant methods under the CanvasGeometry namespace to get the path, then write a custom class to read the parse path. Finally, the generated CanvasSvgDocument object is used to save the stream containing the svg content.
Please refer to the following sample to do these steps. (Note: download Win2D.uwp package)
XAML code:
<Page
x:Class="CanvasToSVG.MainPage"
…
mc:Ignorable="d"
Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<Grid>
<StackPanel>
<InkCanvas x:Name="MyInkConntrol" Height="500">
</InkCanvas>
<InkToolbar Grid.Row="1" TargetInkCanvas="{x:Bind MyInkConntrol}" HorizontalAlignment="Left">
<InkToolbarCustomToolButton Click="save">
<SymbolIcon Symbol="Save" />
</InkToolbarCustomToolButton>
</InkToolbar>
<Line Stroke="Black"/>
<Image Name="ImageControl"></Image>
</StackPanel>
</Grid>
</Page>
Code behind:
public sealed partial class MainPage : Page
{
public MainPage()
{
this.InitializeComponent();
MyInkConntrol.InkPresenter.InputDeviceTypes= CoreInputDeviceTypes.Mouse |CoreInputDeviceTypes.Pen |
CoreInputDeviceTypes.Touch;
MyInkConntrol.InkPresenter.StrokesCollected += InkPresenter_StrokesCollected;
MyInkConntrol.InkPresenter.StrokesErased += InkPresenter_StrokesErased;
}
private async void InkPresenter_StrokesErased(Windows.UI.Input.Inking.InkPresenter sender, Windows.UI.Input.Inking.InkStrokesErasedEventArgs args)
{
await RenderSvg();
}
private async void InkPresenter_StrokesCollected(Windows.UI.Input.Inking.InkPresenter sender, Windows.UI.Input.Inking.InkStrokesCollectedEventArgs args)
{
await RenderSvg();
}
public async Task RenderSvg()
{
using (var stream=new InMemoryRandomAccessStream())
{
await RenderSvg(stream);
var image= new SvgImageSource();
await image.SetSourceAsync(stream);
ImageControl.Source = image;
}
}
public async Task RenderSvg(IRandomAccessStream randomAccessStream)
{
var sharedDevice = CanvasDevice.GetSharedDevice();
using (var offscreen = new CanvasRenderTarget(sharedDevice, (float)MyInkConntrol.RenderSize.Width, (float)MyInkConntrol.RenderSize.Height, 96))
{
using (var session = offscreen.CreateDrawingSession())
{
var svgDocument = new CanvasSvgDocument(sharedDevice);
svgDocument.Root.SetStringAttribute("viewBox", $"0 0 {MyInkConntrol.RenderSize.Width} {MyInkConntrol.RenderSize.Height}");
foreach (var stroke in MyInkConntrol.InkPresenter.StrokeContainer.GetStrokes())
{
var canvasGeometry = CanvasGeometry.CreateInk(session, new[] { stroke }).Outline();
var pathReceiver = new CanvasGeometryToSvgPathReader();
canvasGeometry.SendPathTo(pathReceiver);
var element = svgDocument.Root.CreateAndAppendNamedChildElement("path");
element.SetStringAttribute("d", pathReceiver.Path);
var color = stroke.DrawingAttributes.Color;
element.SetColorAttribute("fill", color);
}
await svgDocument.SaveAsync(randomAccessStream);
}
}
}
private async void save(object sender, RoutedEventArgs e)
{
FileSavePicker savePicker = new FileSavePicker();
savePicker.SuggestedStartLocation = PickerLocationId.DocumentsLibrary;
savePicker.FileTypeChoices.Add("svg file", new List<string>() { ".svg" });
savePicker.SuggestedFileName = "NewSvgfile1";
var file = await savePicker.PickSaveFileAsync();
if (file != null)
{
using (var writeStream = (await file.OpenStreamForWriteAsync()).AsRandomAccessStream())
{
await RenderSvg(writeStream);
await writeStream.FlushAsync();
}
}
}
}
Custom class:
public class CanvasGeometryToSvgPathReader: ICanvasPathReceiver
{
private readonly Vector2 _ratio;
private List<string> Parts { get; }
public string Path => string.Join(" ", Parts);
public CanvasGeometryToSvgPathReader() : this(Vector2.One)
{ }
public CanvasGeometryToSvgPathReader(Vector2 ratio)
{
_ratio = ratio;
Parts = new List<string>();
}
public void BeginFigure(Vector2 startPoint, CanvasFigureFill figureFill)
{
Parts.Add($"M{startPoint.X / _ratio.X} {startPoint.Y / _ratio.Y}");
}
public void AddArc(Vector2 endPoint, float radiusX, float radiusY, float rotationAngle, CanvasSweepDirection sweepDirection, CanvasArcSize arcSize)
{
}
public void AddCubicBezier(Vector2 controlPoint1, Vector2 controlPoint2, Vector2 endPoint)
{
Parts.Add($"C{controlPoint1.X / _ratio.X},{controlPoint1.Y / _ratio.Y} {controlPoint2.X / _ratio.X},{controlPoint2.Y / _ratio.Y} {endPoint.X / _ratio.X},{endPoint.Y / _ratio.Y}");
}
public void AddLine(Vector2 endPoint)
{
Parts.Add($"L {endPoint.X / _ratio.X} {endPoint.Y / _ratio.Y}");
}
public void AddQuadraticBezier(Vector2 controlPoint, Vector2 endPoint)
{
//
}
public void SetFilledRegionDetermination(CanvasFilledRegionDetermination filledRegionDetermination)
{
//
}
public void SetSegmentOptions(CanvasFigureSegmentOptions figureSegmentOptions)
{
//
}
public void EndFigure(CanvasFigureLoop figureLoop)
{
Parts.Add("Z");
}
}

In the end I was able to use the XmlWriter class to write my own canvas-to-svg converter. Using the example in the question:
using Microsoft.Graphics.Canvas;
using Microsoft.Graphics.Canvas.Svg;
using Microsoft.Graphics.Canvas.UI.Xaml;
using System;
using System.Xml;
using System.Threading.Tasks;
using Windows.Storage.Streams;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Shapes;
namespace MyApp
{
public class ExportSVG
{
private XmlWriter Writer { get; }
public SVGWriter(System.IO.Stream stream)
{
Writer = XmlWriter.Create(stream, new XmlWriterSettings()
{
Indent = true,
});
Writer.WriteStartElement("svg", "http://www.w3.org/2000/svg");
Write("version", "1.1");
}
public void AddCanvases(UIElement element)
{
if (element is Grid grid)
{
foreach (UIElement child in grid.Children)
{
AddCanvases(child);
}
}
else if (element is Canvas canvas)
{
AddCanvas(canvas);
}
}
public void AddCanvas(Canvas canvas)
{
foreach (UIElement element in canvas.Children)
{
if (element is Path path)
{
else if (path.Data is EllipseGeometry ellipseGeometry)
{
Writer.WriteStartElement("ellipse");
Write("stroke", ellipseGeometry.Stroke);
Write("stroke-width", ellipseGeometry.StrokeThickness);
Write("cx", ellipseGeometry.Center.X);
Write("cy", ellipseGeometry.Center.Y);
Write("rx", ellipseGeometry.RadiusX);
Write("ry", ellipseGeometry.RadiusY);
Writer.WriteEndElement();
}
}
else if (element is TextBlock textBlock)
{
Writer.WriteStartElement("text");
Write("x", Canvas.GetLeft(textBlock));
Write("y", Canvas.GetTop(textBlock) + textBlock.ActualHeight);
Write("font-family", textBlock.FontFamily.Source);
Write("font-size", $"{textBlock.FontSize}px");
Writer.WriteString(textBlock.Text);
Writer.WriteEndElement();
}
}
}
private void Write(string name, string value)
{
Writer.WriteAttributeString(name, value);
}
private void Write(string name, double value)
{
Write(name, ((float)value).ToString());
}
public void Dispose()
{
Writer.WriteEndElement();
Writer.Close();
Writer.Dispose();
}
}
}

Phone list c# (Reading from a file)

This is a pretty simple program. It IS a homework project. The program should start, read a .txt file, populate the name list and when you click on the name, the phone number is displayed. I have it coded, no errors, no warnings. It will not read the .txt file and I can't figure out why. I've been scouring my book, youtube, even here, but can't pin it down. Any help would be appreciated. Here is my current code.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
namespace Phonebook
{
struct PhoneBookEntry
{
public string name;
public string phone;
}
public partial class Form1 : Form
{
// FIeld to hold a list of PhoneBookEntry objects.
private List<PhoneBookEntry> phoneList = new List<PhoneBookEntry>();
public Form1()
{
InitializeComponent();
}
// The ReadFile method reads the contents of the
//PhoneList.txt file and tores it as PhoneBokeEntry
// objects in the phoneList.
private void ReadFile()
{
try
{
StreamReader inputFile; // To read the file
string line; // To hold a line from the file
// Create an instance of the PhoneBookEntry structure.
PhoneBookEntry entry = new PhoneBookEntry();
// Create a delimiter array.
char[] delim = { ',' };
// Open the PhoneList file.
inputFile = File.OpenText("PhoneList.txt");
// Read the lines from the file.
while (!inputFile.EndOfStream)
{
// Read a line from the file.
line = inputFile.ReadLine();
// Tokenize the line
string[] tokens = line.Split(delim);
// Store the tokens in the entry object.
entry.name = tokens[0];
entry.phone = tokens[1];
// Add the entry object to the List.
phoneList.Add(entry);
}
}
catch (Exception ex)
{
// Display an error message.
MessageBox.Show(ex.Message);
}
}
// The DisplayNames method displays the list of names
// in the namesListBox conrol.
private void DisplayNames()
{
foreach (PhoneBookEntry entry in phoneList)
{
nameListBox.Items.Add(entry.name);
}
}
private void Form1_Load(object sender, EventArgs e)
{
// Read the PhoneList.txt file.
ReadFile();
// DIsplay the names.
DisplayNames();
}
private void nameListBox_SelectedIndexChanged(object sender, EventArgs e)
{
// Get the index of the selected item.
int index = nameListBox.SelectedIndex;
// Display the corresponding phone number.
phoneLabel.Text = phoneList[index].phone;
}
private void exitButton_Click(object sender, EventArgs e)
{
// close the form.
this.Close();
}
private void Form1_Load_1(object sender, EventArgs e)
{
}
}
}

C# Convert pdf to txt

I warmly welcome...
I have a question I'm trying to convert PDF to txt and I can not save a txt file ?? Someone please help me ??
using System;
using System.Text;
using System.Windows.Forms;
using iTextSharp.text.pdf;
using iTextSharp.text.pdf.parser;
using System.IO;
namespace ZestawienieFaktur
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
string[] filePaths = Directory.GetFiles(#"D:\\faktury\\", "*.pdf");
foreach (string fp in filePaths)
{
ExtractTextFromPdf(fp);
}
}
public static string ExtractTextFromPdf(string path)
{
using (PdfReader reader = new PdfReader(path))
{
StringBuilder text = new StringBuilder();
for (int i = 1; i <= reader.NumberOfPages; i++)
{
text.Append(PdfTextExtractor.GetTextFromPage(reader, i));
}
string lines = text.ToString();
using (var file = new StreamWriter(#"D:\faktury\test1.txt"))
{
file.WriteLine(lines);
file.Close();
}
}
}
}
}
In the folder I have a few pdf files with different names.
And I want all converted to the format of txt.
Big thx for answer...

You should remove the return keyword instead and just return void. The reason why it's not executing is because it stops executing the rest of the code after return. Change it to this:
public static void ExtractTextFromPdf(string path)
{
using (PdfReader reader = new PdfReader(path))
{
StringBuilder text = new StringBuilder();
for (int i = 1; i <= reader.NumberOfPages; i++)
{
text.Append(PdfTextExtractor.GetTextFromPage(reader, i));
}
string lines = "";
using(var file = new StreamWriter(path2))
{
file.WriteLine(lines);
file.Close();
}
}
}
Hope it helps!

OK WORKS thx friends...
using System;
using System.Text;
using System.Windows.Forms;
using iTextSharp.text.pdf;
using iTextSharp.text.pdf.parser;
using System.IO;
namespace ZestawienieFaktur
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
string[] filePaths = Directory.GetFiles(#"D:\faktury\", "*.pdf");
foreach (string fp in filePaths)
{
ExtractTextFromPdf(fp);
}
}
public static string ExtractTextFromPdf(string path)
{
using (PdfReader reader = new PdfReader(path))
{
StringBuilder text = new StringBuilder();
for (int i = 1; i <= reader.NumberOfPages; i++)
{
text.Append(PdfTextExtractor.GetTextFromPage(reader, i));
}
string lines = text.ToString();
using (var file = new StreamWriter(#"D:\faktury\test1.txt"))
{
file.WriteLine(lines);
file.Close();
}
return lines;
}
}
}
}

Isolated Storage Exception while reading a stream next time

I am creating an application for WP7.1 with Phonegap in which I have to download a video and save it in Isolated Storage.
Now while reading that video, for the first time I can read it correctly, but after that I am not able to read the stream. This exception occurs every I try to read that video after I have read it once : Operation not permitted on IsolatedStorageFileStream.
Taken the code from : How to play embedded video in WP7 - Phonegap?
and added Pause and Stop functionality.
using System;
using System.IO;
using System.IO.IsolatedStorage;
using System.Runtime.Serialization;
using System.Windows;
using System.Windows.Controls;
using Microsoft.Phone.Controls;
using WP7CordovaClassLib.Cordova.JSON;
namespace WP7CordovaClassLib.Cordova.Commands
{
public class Video : BaseCommand
{
/// <summary>
/// Video player object
/// </summary>
private MediaElement _player;
Grid grid;
[DataContract]
public class VideoOptions
{
/// <summary>
/// Path to video file
/// </summary>
[DataMember(Name = "src")]
public string Src { get; set; }
}
public void Play(string args)
{
VideoOptions options = JsonHelper.Deserialize<VideoOptions>(args);
Deployment.Current.Dispatcher.BeginInvoke(() =>
{
try
{
_Play(options.Src);
DispatchCommandResult(new PluginResult(PluginResult.Status.OK));
}
catch (Exception e)
{
DispatchCommandResult(new PluginResult(PluginResult.Status.ERROR, e.Message));
GoBack();
}
});
}
private void _Play(string filePath)
{
if (_player != null)
{
if (_player.CurrentState == System.Windows.Media.MediaElementState.Paused)
{
_player.Play();
}
}
else
{
// this.player is a MediaElement, it must be added to the visual tree in order to play
PhoneApplicationFrame frame = Application.Current.RootVisual as PhoneApplicationFrame;
if (frame != null)
{
PhoneApplicationPage page = frame.Content as PhoneApplicationPage;
if (page != null)
{
grid = page.FindName("VideoPanel") as Grid;
if (grid != null && _player == null)
{
_player = new MediaElement();
grid.Children.Add(this._player);
grid.Visibility = Visibility.Visible;
_player.Visibility = Visibility.Visible;
_player.MediaEnded += new RoutedEventHandler(_player_MediaEnded);
}
}
}
Uri uri = new Uri(filePath, UriKind.RelativeOrAbsolute);
if (uri.IsAbsoluteUri)
{
_player.Source = uri;
}
else
{
using (IsolatedStorageFile isoFile = IsolatedStorageFile.GetUserStoreForApplication())
{
if (isoFile.FileExists(filePath))
{
**using (IsolatedStorageFileStream stream =
new IsolatedStorageFileStream(filePath, FileMode.Open, isoFile))
{
_player.SetSource(stream);
stream.Close();
}
}
else
{
throw new ArgumentException("Source doesn't exist");
}
}
}
_player.Play();
}
}
void _player_MediaEnded(object sender, RoutedEventArgs e)
{
GoBack();
}
public void Pause(string args)
{
Deployment.Current.Dispatcher.BeginInvoke(() =>
{
try
{
_Pause(args);
DispatchCommandResult(new PluginResult(PluginResult.Status.OK));
}
catch (Exception e)
{
DispatchCommandResult(new PluginResult(PluginResult.Status.ERROR, e.Message));
}
});
}
private void _Pause(string filePath)
{
if (_player != null)
{
if (_player.CurrentState == System.Windows.Media.MediaElementState.Playing)
{
_player.Pause();
}
}
}
public void Stop(string args)
{
Deployment.Current.Dispatcher.BeginInvoke(() =>
{
try
{
_Stop(args);
DispatchCommandResult(new PluginResult(PluginResult.Status.OK));
}
catch (Exception e)
{
DispatchCommandResult(new PluginResult(PluginResult.Status.ERROR, e.Message));
}
});
}
private void _Stop(string filePath)
{
GoBack();
}
private void GoBack()
{
if (_player != null)
{
if (_player.CurrentState == System.Windows.Media.MediaElementState.Playing
|| _player.CurrentState == System.Windows.Media.MediaElementState.Paused)
{
_player.Stop();
}
_player.Visibility = Visibility.Collapsed;
_player = null;
}
if (grid != null)
{
grid.Visibility = Visibility.Collapsed;
}
}
}
}
** The exception (Operation not permitted on IsolatedStorageFileStream.) occurs at _Play function while reading the file (Please see ** in code above). First time it runs perfectly and when I come to read the file second time it gives Exception.
What might be the problem?
Is I am doing something wrong?

It sounds like the file is still open from the previous read. If this is the case, you need to specify the fileAccess and fileShare to allow it to be opened by another thread:
using (IsolatedStorageFileStream stream = new IsolatedStorageFileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read, isoFile)

I solved this problem by just setting the source property of the MediaElement to null before navigating back. So, when i come back to play the same video, the MediaElement source is free for it.
Edited the GoBack Function to :
private void GoBack()
{
// see whole code from original question.................
_player.Visibility = Visibility.Collapsed;
_player.Source = null; // added this line
_player = null;
//..................
}
Thanks All.

Error in code: Loading of XML document

this is in reference to a question asked earlier. Here is the complete code and it's giving me an error:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Xml;
using System.Text;
using System.Windows.Forms;
using System.Collections;
using System.IO;
namespace LoadXMLtreeDisplay
{
public partial class TreeDisplay : Form
{
public string Filename
{
get { return filename; }
}
protected string filename;
public TreeDisplay()
{
InitializeComponent();
this.Text = "Tree View of XML File";//Form Title.
}
private void treeDocLoadMethod(string nameofFile)
{
XmlDocument xdoc = new XmlDocument();
xdoc.Load(nameofFile);
this.treeView1.Nodes.Clear();
this.treeView1.Nodes.Add(new TreeNode(xdoc.DocumentElement.Name));
TreeNode tNodeObj = new TreeNode();
tNodeObj = this.treeView1.Nodes[0];
XmlNode xNode = xdoc.DocumentElement;
AddingNodesToTree(tNodeObj, xNode);
treeView1.Nodes[0].Expand();
treeView1.CollapseAll();
}//treeDocLoadMethod
private void AddingNodesToTree(refXmlNode xnode,TreeNode tnode)
{
TreeNode subNode = tnode.Add(xnode.Name);
subNode.Tag = xnode;
foreach (XmlNode subElement in xnode.ChildNodes)
{
AddingNodesToTree(ref subElement, ref subNode);
}
}
private void treeView1_AfterSelect(object sender, System.Windows.Forms.TreeViewEventArgs e)
{ listBox1.Items.Clear();
TreeNode currentNode = e.Node;
XmlElement currentElement = (XmlElement)currentNode.Tag;
XmlAttributeCollection attCol = currentElement.Attributes;
foreach (XmlAttribute xmlatt in attCol)
{
listBox1.Items.Show(xmlatt);
}
}
//Rest of the code is for winform display(various buttons and boxes)
}
}
After compiling this I am getting the error:
Expected class, delegate, enum,
interface, or struct Type or
namespace definition, or end-of-file
expected
Please could you tell me what's the possible source of error and how to rectify it? I am a newbie in C#

There's a space missing in the first line; should be "ref XmlNode" instead of "refXmlNode"
Edit: not the first line (any more); but the line that says:
private void AddingNodesToTree(refXmlNode xnode,TreeNode tnode)