不要在成员签名中嵌套泛型类型

Question

我已经获得了一个扩展类，它实现了具有违反CA1006的签名的以下成员：DoNotNestGenericTypesInMemberSignatures规则。

下面包含警告提到的代码。

我应该如何重构代码来解决CA1006警告？

请记住，我并不是很熟悉表达式树，尽管我对匿名方法，委托和lambdas有很好的理解。

任何帮助将不胜感激。

public static DataServiceQuery<TElement> Expand<TElement, TPropType>(this DataServiceQuery<TElement> source, Expression<Func<TElement, TPropType>> propertySelector) 
    { 
     string includeString = BuildString(propertySelector); 
     return source.Expand(includeString); 
    } 

    private static string BuildString(Expression propertySelector) 
    { 
     switch (propertySelector.NodeType) 
     { 
      case ExpressionType.Lambda: 
       LambdaExpression lambdaExpression = (LambdaExpression)propertySelector; 
       return BuildString(lambdaExpression.Body); 

      case ExpressionType.Quote: 
       UnaryExpression unaryExpression = (UnaryExpression)propertySelector; 
       return BuildString(unaryExpression.Operand); 

      case ExpressionType.MemberAccess: 

       MemberExpression memberExpression = (MemberExpression)propertySelector; 
       MemberInfo propertyInfo = memberExpression.Member; 

       if (memberExpression.Expression is ParameterExpression) 
       { 
        return propertyInfo.Name; 
       } 
       else 
       { 
        // we've got a nested property (e.g. MyType.SomeProperty.SomeNestedProperty) 
        return BuildString(memberExpression.Expression) + "/" + propertyInfo.Name; 
       } 

      case ExpressionType.Call: 
       MethodCallExpression methodCallExpression = (MethodCallExpression)propertySelector; 
       if (IsSubInclude(methodCallExpression.Method)) // check that it's a SubInclude call 
       { 
        // argument 0 is the expression to which the SubInclude is applied (this could be member access or another SubInclude) 
        // argument 1 is the expression to apply to get the included property 
        // Pass both to BuildString to get the full expression 
        return BuildString(methodCallExpression.Arguments[0]) + "/" + 
          BuildString(methodCallExpression.Arguments[1]); 
       } 
       // else drop out and throw 
       break; 
     } 
     throw new InvalidOperationException("Expression must be a member expression or an SubInclude call: " + propertySelector.ToString()); 

    } 

    private static readonly MethodInfo[] SubIncludeMethods; 
    static MyExtensions() 
    { 
     Type type = typeof(MyExtensions); 
     SubIncludeMethods = type.GetMethods().Where(mi => mi.Name == "SubExpand").ToArray(); 
    } 

    private static bool IsSubInclude(MethodInfo methodInfo) 
    { 
     if (methodInfo.IsGenericMethod) 
     { 
      if (!methodInfo.IsGenericMethodDefinition) 
      { 
       methodInfo = methodInfo.GetGenericMethodDefinition(); 
      } 
     } 
     return SubIncludeMethods.Contains(methodInfo); 
    } 

    public static TPropType SubExpand<TSource, TPropType>(this Collection<TSource> source, Expression<Func<TSource, TPropType>> propertySelector) 
     where TSource : class 
     where TPropType : class 
    { 
     throw new InvalidOperationException("This method is only intended for use with DataServiceQueryExtensions.Expand to generate expressions trees"); // no actually using this - just want the expression! 
    } 

    public static TPropType SubExpand<TSource, TPropType>(this TSource source, Expression<Func<TSource, TPropType>> propertySelector) 
     where TSource : class 
     where TPropType : class 
    { 
     throw new InvalidOperationException("This method is only intended for use with DataServiceQueryExtensions.Expand to generate expressions trees"); // no actually using this - just want the expression! 
    } 

Answer 1

该警告是一个普遍的警告，应该帮助您设计一个更好，更简单的公共接口。在这种情况下，您会收到关于在方法中使用Expression<Func<TElement, TPropType>>参数的警告。但是，对于此方法，简化类型没有意义，而应该使用attribute来取消警告，或者从规则集中完全删除规则。

---

是一个愚蠢的例子，你或许应该考虑规则的建议以下是这样的方法：

public void F(Dictionary<String, List<Tuple<String, Int32>>> dictionary);