CShap FEM 文件转换为 GMSH 网格文件 源代码

以下是将CSharp FEM文件转换为GMSH网格文件的源代码：

using System;
using System.IO;

namespace CSharpToGMSH
{
    class Program
    {
        static void Main(string[] args)
        {
            if (args.Length != 2)
            {
                Console.WriteLine("Usage: CSharpToGMSH.exe input.fem output.msh");
                return;
            }

            string inputPath = args[0];
            string outputPath = args[1];

            // Read input file
            string[] inputLines = File.ReadAllLines(inputPath);

            // Extract nodes, elements and element types
            int numNodes = 0;
            int numElements = 0;
            string[] nodeLines = null;
            string[] elementLines = null;
            string[] elementTypeLines = null;

            foreach (string line in inputLines)
            {
                if (line.StartsWith("Nodes:"))
                {
                    numNodes = int.Parse(line.Substring(6));
                    nodeLines = new string[numNodes];

                    for (int i = 0; i < numNodes; i++)
                    {
                        nodeLines[i] = inputLines[i + 1];
                    }
                }
                else if (line.StartsWith("Elements:"))
                {
                    numElements = int.Parse(line.Substring(9));
                    elementLines = new string[numElements];
                    elementTypeLines = new string[numElements];

                    for (int i = 0; i < numElements; i++)
                    {
                        elementLines[i] = inputLines[i + numNodes + 2];
                        elementTypeLines[i] = inputLines[i + numNodes + numElements + 3];
                    }
                }
            }

            // Write output file
            using (StreamWriter writer = new StreamWriter(outputPath))
            {
                // Write header
                writer.WriteLine("$MeshFormat");
                writer.WriteLine("2.2 0 8");
                writer.WriteLine("$EndMeshFormat");

                // Write nodes
                writer.WriteLine("$Nodes");
                writer.WriteLine(numNodes);

                for (int i = 0; i < numNodes; i++)
                {
                    string[] tokens = nodeLines[i].Split(' ');
                    writer.WriteLine($"{i + 1} {tokens[0]} {tokens[1]} {tokens[2]}");
                }

                writer.WriteLine("$EndNodes");

                // Write elements
                writer.WriteLine("$Elements");
                writer.WriteLine(numElements);

                for (int i = 0; i < numElements; i++)
                {
                    string[] tokens = elementLines[i].Split(' ');
                    int numNodesPerElement = int.Parse(tokens[1]);

                    writer.Write($"{i + 1} {elementTypeLines[i]} 2 0 {numNodesPerElement}");

                    for (int j = 0; j < numNodesPerElement; j++)
                    {
                        writer.Write($" {int.Parse(tokens[j + 2])}");
                    }

                    writer.WriteLine();
                }

                writer.WriteLine("$EndElements");
            }
        }
    }
}