GraphVizNet

.NET wrapper for the command-line GraphViz native binaries. The binaries (version 2.44.0) are included and deployed with this package.

Usage

To render an in-memory DOT graph to a PNG file

var graphViz = new GraphViz();
graphViz.LayoutAndRenderDotGraph(graph, outputFilePath, "png");

To render an in-memory DOT graph to an in-memory PNG file

var graphViz = new GraphViz();
byte[] renderedGraph = graphViz.LayoutAndRenderDotGraph(graph, "png");

To render a DOT graph from a file to a PNG file

var graphViz = new GraphViz();
graphViz.LayoutAndRenderDotGraphFromFile(inputFilePath, outputFilePath, "png");

To render a DOT graph from a file to an in-memory PNG file

var graphViz = new GraphViz();
byte[] renderedGraph = graphViz.LayoutAndRenderDotGraphFromFile(inputFilePath, "png");

For more flexible rendering use the LayoutAndRender method, with the parameters:

• graphFilePath - Path to graph file, can be null but then the graph must not be null.
• graph-The graph, can be null but then the graph file path must not be null.
• outputFilePath - Path to output file. If it's null, the returned byte array will have the command line output.
• layoutAlgorithm - The layout algorithm, if it's null it will default to "dot". See https://www.graphviz.org/pdf/dot.1.pdf for more layout algorithms.
• outputFormat - The output format, if it's null it will default to "dot". See https://www.graphviz.org/doc/info/output.html for more output formats.
• extraCommandLineFlags - Any extra command line flags. See https://www.graphviz.org/doc/info/command.html.

These are the settings for the wrapper itself:

• TimeoutInMs - specifies the timeout (in milliseconds) for the launched process, default is 30000.
• TreatWarningsAsErrors - throws exception on rendering if there are any warnings, default is false.
• GraphVizBinariesDirectory - specifies the location of the GraphViz binaries, default is graphviz.

var graphViz = new GraphViz();
graphViz.Config.TreatWarningsAsErrors = true;

If you create your own library or NuGet package that references the GraphVizNet package, set the PrivateAssets on the package reference to explicitly exclude contentFiles, that will ensure the GraphViz binaries are copied to the output of projects that reference your library/NuGet. One example would be to set it to none

<ItemGroup>
  <PackageReference Include="GraphVizNet" Version="1.0.0" PrivateAssets="none" />
</ItemGroup>

Launch process vs PInvoke

There are two ways of integrating GraphViz native binaries: launching the "dot" tool in a new process or using PInvoke. This library uses the former approach, see https://github.com/valentiniliescu/GraphVizNet-PInvoke for my experimentation with the latter.