Unity文字操作の処理

AddCustomNameSpace.cs

using UnityEngine;
using UnityEditor;
using System.IO;

namespace ScriptNamespace
{
    public class AddCustomNameSpace : UnityEditor.AssetModificationProcessor
    {
        public static void OnWillCreateAsset(string path)
        {
            var setting = Resources.Load("NewScriptSetting") as NewScriptSetting;
            if (setting == null) return;
            var namespaceString = setting.nameSpace;

            var filePath = path.Replace(".meta", "");
            if (System.IO.Path.GetExtension(filePath) != ".cs") return;
            var index = Application.dataPath.LastIndexOf("Assets", System.StringComparison.Ordinal);
            var absoluteFilePath = Application.dataPath.Substring(0, index) + filePath;

            using (var stream = new FileStream(absoluteFilePath, FileMode.Open, FileAccess.ReadWrite, FileShare.None))
            {
                using (var reader = new StreamReader(stream))
                {
                    using (var writer = new StreamWriter(stream))
                    {
                        var texts = reader.ReadToEnd();
                        stream.Position = 0;
                        var lines = texts.Split('\n');
                        // 全行にインデント
                        for (int i = 0; i < lines.Length; i++)
                        {
                            lines[i] = lines[i].Insert(0, "\t");
                        }
                        texts = string.Join("\n", lines);
                        texts = texts.Insert(0, string.Format("namespace {0}\n{1}\n", namespaceString, System.Text.RegularExpressions.Regex.Unescape("{")));
                        texts = texts.Insert(texts.Length - 1, "}\n");
                        writer.Write(texts);
                    }
                }
            }

            AssetDatabase.Refresh();
        }
    }
}