系统国际化改造整体设计思路如下：
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提供一个工具，识别前后端代码中的中文，形成多语言词条，按语言、界面、模块统一管理多有的多语言词条
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提供一个翻译服务，批量翻译多语言词条
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提供一个词条服务，支持后端代码在运行时根据用户登录的语言，动态获取对应的多语言文本
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提供前端多语言JS生成服务，按界面动态生成对应的多语言JS文件，方便前端VUE文件使用。
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提供代码替换工具，将VUE前端代码中的中文替换为$t("词条ID")，后端代码中的中文替换为TermService.Current.GetText("词条ID").
今天，我们在上篇文章的基础上，继续介绍基于Roslyn抽取词条、更新代码。
一、业务背景
先说一下业务背景，后端.NET代码中存在大量的中文提示和异常消息，甚至一些中文返回值文本。
这些中文文字都需要识别出来，抽取为多语言词条，同时将代码替换为调用多语言词条服务获取翻译后的文本。
例如：
private static void CheckMd5(string fileName, string md5Data){string md5Str = MD5Service.GetMD5(fileName);if (!string.Equals(md5Str, md5Data, StringComparison.OrdinalIgnoreCase)){throw new CustomException(PackageExceptionConst.FileMd5CheckFailed, "服务包文件MD5校验失败：" + fileName);}}
代码中需要将“服务包文件MD5校验失败”这个文本做多语言改造。
这里通过调用多语言词条服务I18NTermService，根据线程上下文中设置的语言，获取对应的翻译文本。例如以下代码：
var text=T.Core.I18N.Service.TermService.Current.GetTextFormatted("词条ID"，"默认文本");throw new CustomException(PackageExceptionConst.FileMd5CheckFailed, text + fileName);
以上背景下，我们准备使用Roslyn技术对代码进行中文扫描，对扫描出来的文本，做词条抽取、代码替换。
二、使用Roslyn技术对代码进行中文扫描
首先，我们先定义好代码中多语言词条的扫描结果类TermScanResult
1 [Serializable]2 public class TermScanResult3 {4 public Guid Id { get; set; }5 public string OriginalText { get; set; }67 public string ChineseText { get; set; }89 public string SlnName { get; set; }1011 public string ProjectName { get; set; }1213 public string ClassFile { get; set; }1415 public string MethodName { get; set; }1617 public string Code { get; set; }1819 public I18NTerm I18NTerm { get; set; }2021 public string SlnPath { get; set; }2223 public string ClassPath { get; set; }24 28 public string SubSystemCode { get; set; }2930 public override string ToString()31 {32 return Code;33 }34 }
上述代码中SubSystemCode是一个业务管理维度。大家忽略即可。我们会以sln解决方案为单位，扫描代码中的中文文字。以下是具体的实现代码
public async Task<List<TermScanResult>> CheckSln(string slnPath, System.ComponentModel.BackgroundWorker backgroundWorker, SubSystemFile subSystemFiles, string subSystem){var slnFile = new FileInfo(slnPath);var results = new List<TermScanResult>();MSBuildHelper.RegisterMSBuilder();var solution = await MSBuildWorkspace.Create().OpenSolutionAsync(slnPath);var subSystemInfo = subSystemFiles?.SubSystemSlnMappings.FirstOrDefault(w => w.SlnName.Select(s => s += ".sln").Contains(slnFile.Name.ToLower()));if (solution.Projects != null && solution.Projects.Count() > 0){foreach (var project in solution.Projects.ToList()){backgroundWorker.ReportProgress(10, $"扫描Project: {project.Name}");var documents = project.Documents.Where(x => x.Name.Contains(".cs"));if (project.Name.ToLower().Contains("test")){continue;}var codeReplace = new CodeReplace();foreach (var document in documents){var tree = await document.GetSyntaxTreeAsync();var root = tree.GetCompilationUnitRoot();if (root.Members == null || root.Members.Count == 0) continue;//membervar classDeclartions = root.DescendantNodes().Where(i => i is ClassDeclarationSyntax);foreach (var classDeclare in classDeclartions){var programDeclaration = classDeclare as ClassDeclarationSyntax;if (programDeclaration == null) continue;foreach (var memberDeclarationSyntax in programDeclaration.Members){foreach (var item in GetLiteralStringExpression(memberDeclarationSyntax)){var statementCode = item.Item1;foreach (var syntaxNode in item.Item3){ExpressionSyntaxParser expressionSyntaxParser = new ExpressionSyntaxParser();var text = "";var expressionSyntax = expressionSyntaxParser.GetExpressionSyntaxVerifyRule(syntaxNode as ExpressionSyntax, statementCode);if (expressionSyntax != null){// 排除if (expressionSyntaxParser.IsExcludeCaller(expressionSyntax, statementCode)){continue;}text = expressionSyntaxParser.GetExpressionSyntaxOriginalText(expressionSyntax, statementCode);if (expressionSyntax is Microsoft.CodeAnalysis.CSharp.Syntax.InterpolatedStringExpressionSyntax){text = expressionSyntaxParser.GetExpressionSyntaxOriginalText(expressionSyntax, statementCode);if (expressionSyntax is Microsoft.CodeAnalysis.CSharp.Syntax.LiteralExpressionSyntax){if (!expressionSyntax.IsKind(SyntaxKind.StringLiteralExpression)){continue;}text = expressionSyntax.NormalizeWhitespace().ToString();}}}if (CheckChinese(text) == false) continue;if (string.IsNullOrWhiteSpace(text)) continue;if (string.IsNullOrWhiteSpace(text.Replace("\"", "").Trim())) continue;results.Add(new TermScanResult(){Id = Guid.NewGuid(),ClassPath = programDeclaration.SyntaxTree.FilePath,SlnPath = slnPath,OriginalText = text.Replace("\"", "").Trim(),ChineseText = text,SlnName = slnFile.Name,ProjectName = project.Name,ClassFile = programDeclaration.Identifier.Text,MethodName = item.Item2,Code = statementCode,SubSystemCode = subSystem});}}}}}}}return results;}
上述代码中，我们先使用MSBuilder编译，构建 sln解决方案
MSBuildHelper.RegisterMSBuilder();var solution = await MSBuildWorkspace.Create().OpenSolutionAsync(slnPath);
然后遍历solution下的各个Project中的class类
foreach (var project in solution.Projects.ToList())var documents = project.Documents.Where(x => x.Name.Contains(".cs"));
然后遍历类中声明、成员、方法中的每行代码，通过正则表达式识别是否有中文字符
public static bool CheckChinese(string strZh){Regex re = new Regex(@"[\u4e00-\u9fa5]+");if (re.IsMatch(strZh)){return true;}return false;}
如果存在中文字符，作为扫描后的结果，识别为多语言词条
results.Add(new TermScanResult(){Id = Guid.NewGuid(),ClassPath = programDeclaration.SyntaxTree.FilePath,SlnPath = slnPath,OriginalText = text.Replace("\"", "").Trim(),ChineseText = text,SlnName = slnFile.Name,ProjectName = project.Name,ClassFile = programDeclaration.Identifier.Text,MethodName = item.Item2,Code = statementCode, //管理维度SubSystemCode = subSystem //管理维度});
TermScanResult中没有对词条属性赋值。
public I18NTerm I18NTerm { get; set; }下一篇文章的代码中，我们会通过多语言翻译服务，将翻译后的文本放到I18NTerm 属性中，作为多语言词条。
三、代码替换
代码替换这块逻辑中，我们设计了一个类SourceWeaver，对上一步的代码扫描结果，进行代码替换
CodeScanReplace这个方法中完成了代码的二次扫描和替换
/// <summary>/// 源代码替换服务/// </summary>public class SourceWeaver{List<CommonTermDto> commonTerms = new List<CommonTermDto>();List<CommonTermDto> commSubTerms = new List<CommonTermDto>();public SourceWeaver(){commonTerms = JsonConvert.DeserializeObject<List<CommonTermDto>>(File.ReadAllText("comm_data.json"));commSubTerms = JsonConvert.DeserializeObject<List<CommonTermDto>>(File.ReadAllText("comm_sub_data.json"));}public async Task CodeScanReplace(Tuple<List<I18NTerm>, List<TermScanResult>> result, System.ComponentModel.BackgroundWorker backgroundWorker){try{backgroundWorker.ReportProgress(0, "正在对代码进行替换.");var termScanResultGroupBy = result.Item2.GroupBy(g => g.SlnName);foreach (var termScanResult in termScanResultGroupBy){var termScan = termScanResult.FirstOrDefault();MSBuildHelper.RegisterMSBuilder();var solution = await MSBuildWorkspace.Create().OpenSolutionAsync(termScan.SlnPath).ConfigureAwait(false);if (solution.Projects.Any()){foreach (var project in solution.Projects.ToList()){if (project.Name.ToLower().Contains("test")){continue;}var projectTermScanResults = result.Item2.Where(f => f.ProjectName == project.Name);var documents = project.Documents.Where(x =>{return x.Name.Contains(".cs") && projectTermScanResults.Any(f => $"{f.ClassPath}" == x.FilePath);});foreach (var document in documents){var tree = await document.GetSyntaxTreeAsync().ConfigureAwait(false);var root = tree.GetCompilationUnitRoot();if (root.Members.Count == 0) continue;var classDeclartions = root.DescendantNodes().Where(i => i is ClassDeclarationSyntax);List<MemberDeclarationSyntax> syntaxNodes = new List<MemberDeclarationSyntax>();foreach (var classDeclare in classDeclartions){if (!(classDeclare is ClassDeclarationSyntax programDeclaration)) continue;var className = programDeclaration.Identifier.Text;foreach (var method in programDeclaration.Members){if (method is ConstructorDeclarationSyntax){syntaxNodes.Add((ConstructorDeclarationSyntax)method);}else if (method is MethodDeclarationSyntax){syntaxNodes.Add((MethodDeclarationSyntax)method);}else if (method is PropertyDeclarationSyntax){syntaxNodes.Add(method);}else if (method is FieldDeclarationSyntax){// 注：常量不支持syntaxNodes.Add(method);}}}var terms = termScanResult.Where(f => f.ProjectName == document.Project.Name && f.ClassPath == document.FilePath).ToList();backgroundWorker.ReportProgress(10, $"正在检查{document.FilePath}文件.");ReplaceNodesAndSave(root, syntaxNodes, terms, result, backgroundWorker, document.Name);}}}}}catch (Exception ex){LogUtils.LogError(string.Format("异常类型：{0}\r\n异常消息：{1}\r\n异常信息：{2}\r\n",ex.GetType().Name, ex.Message, ex.StackTrace));backgroundWorker.ReportProgress(0, ex.Message);}}public async void ReplaceNodesAndSave(SyntaxNode classSyntaxNode, List<MemberDeclarationSyntax> syntaxNodes, IEnumerable<TermScanResult> terms, Tuple<List<I18NTerm>, List<TermScanResult>> result,System.ComponentModel.BackgroundWorker backgroundWorker, string className){{//check pro是否存在词条if (AppConfig.Instance.IsCheckTermPro){backgroundWorker.ReportProgress(15, $"词条验证中.");var termsCodes = terms.Select(f => f.I18NTerm.Code).ToList();var size = 100;var p = (result.Item2.Count() + size - 1) / size;using DBHelper dBHelper = new DBHelper();List<I18NTerm> items = new List<I18NTerm>();for (int i = 0; i < p; i++){var list = termsCodes.Skip(i * size).Take(size);Thread.Sleep(10);var segmentItems = await dBHelper.GetTermsAsync(termsCodes).ConfigureAwait(false);items.AddRange(segmentItems);}List<TermScanResult> termScans = new List<TermScanResult>();foreach (var term in terms){if (items.Any(f => f.Code == term.I18NTerm.Code)){termScans.Add(term);}else{backgroundWorker.ReportProgress(20, $"词条{term.OriginalText}未导入到词条库，该词条将忽略替换.");}}terms = termScans;}}var newclassDeclare = classSyntaxNode;newclassDeclare = classSyntaxNode.ReplaceNodes(syntaxNodes,(methodDeclaration, _) =>{MemberDeclarationSyntax newMemberDeclarationSyntax = methodDeclaration;var className = ((ClassDeclarationSyntax)newMemberDeclarationSyntax.Parent).Identifier.Text;List<StatementSyntax> statementSyntaxes = new List<StatementSyntax>();switch (newMemberDeclarationSyntax){case ConstructorDeclarationSyntax:{var blockSyntax = (newMemberDeclarationSyntax as ConstructorDeclarationSyntax).NormalizeWhitespace().Body;if (blockSyntax == null){break;}foreach (var statement in blockSyntax.Statements){var nodeStatement = statement.DescendantNodes();statementSyntaxes.Add(new CodeReplace().ReplaceStatementNodes(statement,new ExpressionSyntaxParser().LiteralStringExpression(nodeStatement), terms, commonTerms, commSubTerms));}break;}case MethodDeclarationSyntax:{var blockSyntax = (methodDeclaration as MethodDeclarationSyntax).NormalizeWhitespace().Body;if (blockSyntax == null){break;}foreach (var statement in blockSyntax.Statements){var nodeStatement = statement.DescendantNodes();statementSyntaxes.Add(new CodeReplace().ReplaceStatementNodes(statement,new ExpressionSyntaxParser().LiteralStringExpression(nodeStatement), terms, commonTerms, commSubTerms));}break;}case PropertyDeclarationSyntax:{var propertyDeclarationSyntax = newMemberDeclarationSyntax as PropertyDeclarationSyntax;var nodeStatement = propertyDeclarationSyntax.DescendantNodes();return new CodeReplace().ReplacePropertyNodes(newMemberDeclarationSyntax as PropertyDeclarationSyntax,new ExpressionSyntaxParser().LiteralStringExpression(nodeStatement), terms, commonTerms, commSubTerms);}case FieldDeclarationSyntax:{var fieldDeclarationSyntax = newMemberDeclarationSyntax as FieldDeclarationSyntax;var nodeStatement = fieldDeclarationSyntax.DescendantNodes();return new CodeReplace().ReplaceFiledNodes(fieldDeclarationSyntax,new ExpressionSyntaxParser().LiteralStringExpression(nodeStatement), terms, commonTerms, commSubTerms);}}backgroundWorker.ReportProgress(50, $"解析并对类文件{className}中的方法做语句替换.");// 替换方法内部if (newMemberDeclarationSyntax is MethodDeclarationSyntax){return new CodeReplace().ReplaceMethodDeclaration(newMemberDeclarationSyntax as MethodDeclarationSyntax, statementSyntaxes);}else if (newMemberDeclarationSyntax is ConstructorDeclarationSyntax){return new CodeReplace().ReplaceConstructorDeclaration(newMemberDeclarationSyntax as ConstructorDeclarationSyntax, statementSyntaxes);}return newMemberDeclarationSyntax;});var sourceStr = newclassDeclare.NormalizeWhitespace().GetText().ToString();File.WriteAllText(newclassDeclare.SyntaxTree.FilePath, sourceStr);backgroundWorker.ReportProgress(100, $"完成{className}的替换.");}}
关键的代码语义替换的实现代码：
public StatementSyntax ReplaceStatementNodes(StatementSyntax statement, List<ExpressionSyntax> expressionSyntaxes, IEnumerable<TermScanResult> terms, List<CommonTermDto> commonTerms, List<CommonTermDto> commSubTerms){var statementSyntax = statement.ReplaceNodes(expressionSyntaxes, (syntaxNode, _) =>{var statementStr = statement.NormalizeWhitespace().ToString();var argumentLists = statement.DescendantNodes().OfType<InvocationExpressionSyntax>();ExpressionSyntaxParser expressionSyntaxParser = new ExpressionSyntaxParser();return expressionSyntaxParser.ExpressionSyntaxTermReplace(syntaxNode, statementStr, terms, commonTerms, commSubTerms);});return statementSyntax;}
这里，我们抽象了一个ExpressionSyntaxParser 类，负责替换代码：
T.Core.I18N.Service.TermService.Current.GetTextFormatted
public ExpressionSyntax ExpressionSyntaxTermReplace(ExpressionSyntax syntaxNode, string statementStr, IEnumerable<TermScanResult> terms, List<CommonTermDto> commonTerms, List<CommonTermDto> commSubTerms){var expressionSyntax = GetExpressionSyntaxVerifyRule(syntaxNode, statementStr);var originalText = GetExpressionSyntaxOriginalText(expressionSyntax, statementStr);var I18Expr = "";var interpolationSyntaxes = syntaxNode.DescendantNodes().OfType<InterpolationSyntax>();var term = terms.FirstOrDefault(i => i.ChineseText == originalText);if (term == null)return syntaxNode;string termcode = term.I18NTerm.Code;if (syntaxNode is InterpolatedStringExpressionSyntax){if (interpolationSyntaxes.Count() > 0){var parms = "";foreach (var item in interpolationSyntaxes){parms += $",{item.ToString().TrimStart('{').TrimEnd('}')}";}I18Expr = "$\"{T.Core.I18N.Service.TermService.Current.GetTextFormatted(\"" + termcode + "\", " + originalText + parms + ")}\"";var token1 = SyntaxFactory.Token(default, SyntaxKind.StringLiteralToken, I18Expr, "", default);return SyntaxFactory.LiteralExpression(SyntaxKind.StringLiteralExpression, token1);}else{var startToken = SyntaxFactory.Token(SyntaxKind.InterpolatedStringStartToken);if ((syntaxNode as InterpolatedStringExpressionSyntax).StringStartToken.Value == startToken.Value){// 如果本身有"$"I18Expr = "$\"{T.Core.I18N.Service.TermService.Current.GetText(\"" + termcode + "\"," + originalText + ")}";}else{// 如果没有"$"I18Expr = "$\"{T.Core.I18N.Service.TermService.Current.GetText(\"" + termcode + "\",\\teld\"" + originalText + "\")}";I18Expr = I18Expr.Replace("\\teld", "$");}}}else{I18Expr = "$\"{T.Core.I18N.Service.TermService.Current.GetText(\"" + termcode + "\"," + originalText + ")}";}var token = SyntaxFactory.Token(default(SyntaxTriviaList), SyntaxKind.InterpolatedVerbatimStringStartToken, I18Expr, "$\"", default(SyntaxTriviaList));var literalExpressionSyntax = SyntaxFactory.InterpolatedStringExpression(token);return literalExpressionSyntax;}
T.Core.I18N.Service.TermService这个就是多语言词条服务类，这个类中提供了一个GetText的方法，通过词条编号，获取多语言文本。
代码完成替换后，打开VS，对工程引用多语言词条服务的Nuget包/dll，重新编译代码，手工校对替换后的代码即可。
以上是.NET应用系统的国际化-基于Roslyn抽取词条、更新代码的分享。
