SvgDocument Handling and Mutation

SvgDocument is the highest-level editable representation in the runtime. Use it when you want to inspect or mutate SVG DOM state instead of working at the lower ShimSkiaSharp.SKPicture command level.

Loading from an existing document

If your code already has a parsed document, pass it directly to SKSvg or the Avalonia wrapper:

using Svg;
using Svg.Skia;

var document = new SvgDocument
{
    Width = 80,
    Height = 40
};

using var svg = new SKSvg();
svg.FromSvgDocument(document);

using Avalonia.Svg.Skia;
using Svg;

var source = SvgSource.LoadFromSvgDocument(new SvgDocument());

SKSvg.SourceDocument then exposes the current document instance backing the renderer.

Full-document mutation and rebuild

For structural edits, broad CSS changes, or any change that touches the root element, mutate the document and rebuild from it:

using System.Drawing;
using Svg;
using Svg.Skia;

using var svg = new SKSvg();
svg.FromSvg(
    "<svg width=\"80\" height=\"40\">" +
    "  <rect id=\"rect-a\" x=\"10\" y=\"8\" width=\"24\" height=\"12\" fill=\"red\" />" +
    "</svg>");

var document = svg.SourceDocument!;
var rect = (SvgRectangle)document.GetElementById("rect-a")!;
rect.Fill = new SvgColourServer(Color.BlueViolet);

svg.FromSvgDocument(document);

FromSvgDocument(...) reparses nothing. It recompiles the retained scene and refreshes the current Picture from the already-mutated DOM.

Reparse the original source with new parameters

When the change is not a DOM edit but a different CSS string or entity dictionary, use ReLoad(...) instead of manually rebuilding the current document:

using Svg.Model;
using Svg.Skia;

SKSvg.CacheOriginalStream = true;

using var svg = new SKSvg();
svg.Load("image.svg", new SvgParameters(null, ".accent { fill: red; }"));

svg.ReLoad(new SvgParameters(null, ".accent { fill: blue; }"));

Avalonia exposes the same pattern through SvgSource.ReLoad(...).

Ownership and cloning

FromSvgDocument(...) uses the SvgDocument instance you pass in. If the same document is shared across multiple views or editors, clone it before mutating:

using Svg;
using Svg.Model.Services;
using Svg.Skia;

var sharedDocument = SvgService.FromSvg("<svg width=\"10\" height=\"10\" />");
var isolatedDocument = (SvgDocument)sharedDocument.DeepCopy();

using var svg = new SKSvg();
svg.FromSvgDocument(isolatedDocument);

That keeps one caller from mutating the DOM another caller still expects to be stable.

When to stay at the DOM layer

Prefer SvgDocument mutation when:

you need to add or remove elements,
you want to edit authored attributes such as fill, stroke, transform, or viewBox,
tooling needs DOM traversal, ids, or XML serialization,
the same mutated document should later be saved back to SVG.

For localized retained-scene refresh after a small DOM edit, continue with Retained Scene Graph Usage and Performance and Retained-Scene Refresh.