GraphLibrary/DrawGraph/GraphMLWriter.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Xml;

namespace DrawGraph
{
    public class GraphMLWriter
    {
        public static void WriteEdges(string path, Edge[] edges, bool direction)
        {
            //XmlDocument doc = new XmlDocument();
            //XmlDeclaration declaration = doc.CreateXmlDeclaration("1.0", "UTF-8", null);
            //var root = doc.CreateElement("graph");
            //var attr = doc.CreateAttribute("id");
            //attr.InnerText = "G";
            //root.Attributes.Append(attr);
            //var dir = doc.CreateAttribute("edgedefault");
            //dir.InnerText = direction ? "directed" : "undirected";
            //root.Attributes.Append(dir);
            //doc.AppendChild(declaration);
            //doc.AppendChild(root);
            //XmlProcessingInstruction pi =
            //    doc.CreateProcessingInstruction("graphml", "xmlns=\"http://graphml.graphdrawing.org/xmlns \" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance \" xsi: schemaLocation = \"http://graphml.graphdrawing.org/xmlns/1.0/graphml.xsd \"");
            //doc.InsertBefore(pi, doc.ChildNodes[1]);

            //for (int i = 0; i < edges.Length; i++)
            //{
            //    XmlNode edge = doc.CreateElement("edge");
            //    var sourceAttribute = doc.CreateAttribute("source");
            //    for (int j = 0; j < nodes.Length; j++)
            //        if (Node.Compare(edges[i].SourceNode, nodes[j]))
            //            sourceAttribute.InnerText = "n" + j.ToString();
            //    edge.Attributes.Append(sourceAttribute);
            //    var targetAttribute = doc.CreateAttribute("target");
            //    for (int j = 0; j < nodes.Length; j++)
            //        if (Node.Compare(edges[i].TargetNode, nodes[j]))
            //            targetAttribute.InnerText = "n" + j.ToString();
            //    edge.Attributes.Append(targetAttribute);
            //    if (edges[i].Weight > 0)
            //    {
            //        var weightAttr = doc.CreateAttribute("weight");
            //        weightAttr.InnerText = edges[i].Weight.ToString();
            //        edge.Attributes.Append(weightAttr);
            //    }
            //    root.AppendChild(edge);
            //}
            //doc.Save(path);
        }

        public static void WriteAllGraph(string path, Node[] nodes, Edge[] edges, bool direction)
        {
            XmlDocument doc = new XmlDocument();
            XmlDeclaration declaration = doc.CreateXmlDeclaration("1.0", "UTF-8", null);
            var root = doc.CreateElement("graph");
            var attr = doc.CreateAttribute("id");
            attr.InnerText = "G";
            root.Attributes.Append(attr);
            var dir = doc.CreateAttribute("edgedefault");
            dir.InnerText = direction ? "directed" : "undirected";
            root.Attributes.Append(dir);
            doc.AppendChild(declaration);
            doc.AppendChild(root);
            XmlProcessingInstruction pi =
                doc.CreateProcessingInstruction("graphml", "xmlns=\"http://graphml.graphdrawing.org/xmlns \" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance \" xsi: schemaLocation = \"http://graphml.graphdrawing.org/xmlns/1.0/graphml.xsd \"");
            doc.InsertBefore(pi, doc.ChildNodes[1]);

            for (int i = 0; i < nodes.Length; i++)
            {
                XmlNode node = doc.CreateElement("node");
                var attribute = doc.CreateAttribute("id");
                attribute.InnerText = "n" + i.ToString();
                node.Attributes.Append(attribute);
                var XCoord = doc.CreateAttribute("positionX");
                XCoord.InnerText = nodes[i].X.ToString();
                node.Attributes.Append(XCoord);
                var YCoord = doc.CreateAttribute("positionY");
                YCoord.InnerText = nodes[i].Y.ToString();
                node.Attributes.Append(YCoord);
                root.AppendChild(node);
            }

            for (int i = 0; i < edges.Length; i++)
            {
                XmlNode edge = doc.CreateElement("edge");
                var sourceAttribute = doc.CreateAttribute("source");
                for (int j = 0; j < nodes.Length; j++)
                    if (Node.Compare(edges[i].SourceNode, nodes[j]))
                        sourceAttribute.InnerText = "n" + j.ToString();
                edge.Attributes.Append(sourceAttribute);
                var targetAttribute = doc.CreateAttribute("target");
                for (int j = 0; j < nodes.Length; j++)
                    if (Node.Compare(edges[i].TargetNode, nodes[j]))
                        targetAttribute.InnerText = "n" + j.ToString();
                edge.Attributes.Append(targetAttribute);
                if (edges[i].Weight > 0)
                {
                    var weightAttr = doc.CreateAttribute("weight");
                    weightAttr.InnerText = edges[i].Weight.ToString();
                    edge.Attributes.Append(weightAttr);
                }
                root.AppendChild(edge);
            }
            doc.Save(path);
        }
    }
}