编写StyleCop自定义规则教程（一）编写中文备注的简单校验规则

基本步骤：

1、 新建Dll项目，引用StyleCop.Dll和StyleCop.Csharp.Dll。

2、 自定义的规则校验类从SourceAnalyzer继承，必须实现public virtual void AnalyzeDocument(CodeDocument document)方法。

3、 在需要触发违反规则的地方使用方法AddViolation。

4、 在项目中增加一个xml嵌入资源，该资源的文件名必须与校验类同名。该xml可以定义校验类显示在StyleCop Setting的规则、规则描述和参数等。

5、 编译成功，将Dll复制到StyleCopy的目录下。

    StyleCop的Documnetaion Rules对代码的文档有一系列的要求，譬如SA1623 要求属性的备注文档开头必须注明whether the property exposes get or set accessors。其校验的实现方式是在备注的开头判断是否有属性访问权对应的Get/ Set字符。中文用户是不大适应用Get和Set作备注的，因此以下一个简单例子实现一个判断中文备注的规则，代替原有的SA1623。

     由于每个Rule都必须有唯一的RuleName和RuleID。RuleName只是用于内部，不被用户看见。RuleID由2位大写字母开头和4位数字组成。SA1623就是RuleID。例子使用MY1623与StyleCop原有的RuleID相对。

     覆盖AnalyzeDocument方法

 public override void AnalyzeDocument(CodeDocument document)
2         {
3             Param.RequireNotNull(document, "document");
4             CsDocument document2 = (CsDocument)document;
5             if ((document2.RootElement != null) && !document2.RootElement.Generated)
6             {
7                 document2.WalkDocument(new CodeWalkerElementVisitor<object>(this.CheckDocumentationForElement), null);
8             }
9         }

WalkDocumnet方法是遍历代码中的各个节点（方法、属性等）。CheckDocumentationForElementelement.ElementType == ElementType.Property是执行具体操作的方法。这里编写的规则只针对属性。

private bool CheckDocumentationForElement(CsElement element, CsElement parentElement, Object settings)
        {
            if (base.Cancel)
            {
                return false;
            }

            if (!element.Generated)
            {
                if (element.ElementType == ElementType.Property)
                {
                    this.ParseHeader(element, element.Header, element.LineNumber, false);
                }
            }
            return true;
        }

private readonly string headerSummaryForGetAndSetAccessor = "可读写";
        private readonly string headerSummaryForGetAccessor = "只读";
        private readonly string headerSummaryForSetAccessor = "只写";
        
        private void ParseHeader(CsElement element, XmlHeader header, int lineNumber, bool partialElement)
        {
            XmlDocument doc = this.LoadHeaderIntoDocument(element, header, lineNumber);
            if ((doc != null) && (element.ElementType == ElementType.Property))
            {
                this.CheckPropertySummaryFormatting(element as Property, doc);
            }
        }

        private XmlDocument LoadHeaderIntoDocument(CsElement element, XmlHeader header, int lineNumber)
        {
            XmlDocument document = new XmlDocument();
            try
            {
                string xml = "<root>" + header.Text + "</root>";
                document.LoadXml(xml);
            }
            catch (XmlException exception)
            {
                base.AddViolation(element, lineNumber, Rules.DocumentationMustContainValidXml, new object[] { exception.Message });
                document = null;
            }
            catch (Exception exception)
            {
                base.AddViolation(element, lineNumber, Rules.DocumentationMustContainValidXml, new object[] { exception.Message });
                document = null;
            }
            return document;
        }
        
        private void CheckPropertySummaryFormatting(Property property, XmlDocument doc)
        {
            XmlNode node = doc.SelectSingleNode("root/summary");
            if (node != null)
            {
                bool flag = ((property.ReturnType.Text == "bool") || (property.ReturnType.Text == "Boolean")) || (property.ReturnType.Text == "System.Boolean");
                if (property.GetAccessor != null)
                {
                    if ((property.SetAccessor == null) || ((property.SetAccessor.AccessModifier != property.AccessModifier) && (((property.AccessModifier == AccessModifierType.Private) || (property.SetAccessor.AccessModifier != AccessModifierType.Private)) || property.SetAccessor.Declaration.ContainsModifier(new CsTokenType[] { CsTokenType.Private }))))
                    {
                        string str2 = headerSummaryForGetAccessor;
                        string str3 = node.InnerText.TrimStart(new char[0]);                        
                        if (!CompareTextWithColon(str3, str2))
                        {
                            base.AddViolation(property, Rules.PropertySummaryDocumentationMustMatchAccessors, new object[] { str2 });
                        }
                    }
                    else
                    {
                        string str = headerSummaryForGetAndSetAccessor;                        
                        if (!CompareTextWithColon(node.InnerText.TrimStart(new char[0]), str))
                        {
                            base.AddViolation(property, Rules.PropertySummaryDocumentationMustMatchAccessors, new object[] { str });
                        }
                    }
                }
                else if (property.SetAccessor != null)
                {
                    string str5 = headerSummaryForSetAccessor;                   
                    if (!CompareTextWithColon(node.InnerText.TrimStart(new char[0]), str5))
                    {
                        base.AddViolation(property, Rules.PropertySummaryDocumentationMustMatchAccessors, new object[] { str5 });
                    }
                }
            }
        }

        private bool CompareTextWithColon(string input, string pattern)
        {
            return Regex.IsMatch(input, pattern + "[:：]", RegexOptions.Singleline);
        }

对应的资源xml

<?xml version="1.0" encoding="utf-8" ?>
<SourceAnalyzer Name="My Documentation Rules">
  <Description>
    Rules which verify the content and formatting of code documentation.
  </Description>  
  <Rules>      
      <Rule Name="DocumentationMustContainValidXml" CheckId="HD1603">
        <Context>The documentation header is composed of invalid Xml: {0}</Context>
        <Description>Indicates that a documentation header is composed of invalid Xml and cannot be parsed.</Description>
      </Rule>      
      <Rule Name="PropertySummaryDocumentationMustMatchAccessors" CheckId="HD1623">
        <Context>属性的摘要文档说明必须使用“{0}”开头</Context>
        <Description>Validates that a property's summary description text begins with the correct syntax, depending upon whether the property exposes get or set accessors.</Description>
      </Rule>
  </Rules>
</SourceAnalyzer>

 其中Description节点的内容是显示在Stylecop Setting窗口下方的文字。Context是违反规则时，显示在VS 错误列表的文字。

附上代码:/Files/Byeah/MyFirstRule.zip

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