2011-02-07 88 views

回答

7

不,塞西爾不提供這樣的方法,因爲塞西爾給我們提供的只是CIL元數據。 (有項目Cecil.Rocks,其中包含了一些有用的擴展方法,但不是這個)

在MSIL方法有一個屬性「覆蓋」,其中包含的方法的引用,這種方法覆蓋(塞西爾的確有MethodDefinition類中的屬性覆蓋)。但是,該屬性僅用於某些特殊情況,如顯式接口實現。通常這個屬性是空的,並且所討論的方法覆蓋哪些方法是基於約定的。這些約定在ECMA CIL標準中進行了描述。簡而言之,一種方法會覆蓋具有相同名稱和相同簽名的方法。

下面的代碼片段可以幫助你和這個討論:http://groups.google.com/group/mono-cecil/browse_thread/thread/b3c04f25c2b5bb4f/c9577543ae8bc40a

public static bool Overrides(this MethodDefinition method, MethodReference overridden) 
    { 
     Contract.Requires(method != null); 
     Contract.Requires(overridden != null); 

     bool explicitIfaceImplementation = method.Overrides.Any(overrides => overrides.IsEqual(overridden)); 
     if (explicitIfaceImplementation) 
     { 
      return true; 
     } 

     if (IsImplicitInterfaceImplementation(method, overridden)) 
     { 
      return true; 
     } 

     // new slot method cannot override any base classes' method by convention: 
     if (method.IsNewSlot) 
     { 
      return false; 
     } 

     // check base-type overrides using Cecil's helper method GetOriginalBaseMethod() 
     return method.GetOriginalBaseMethod().IsEqual(overridden); 
    } 

    /// <summary> 
    /// Implicit interface implementations are based only on method's name and signature equivalence. 
    /// </summary> 
    private static bool IsImplicitInterfaceImplementation(MethodDefinition method, MethodReference overridden) 
    { 
     // check that the 'overridden' method is iface method and the iface is implemented by method.DeclaringType 
     if (overridden.DeclaringType.SafeResolve().IsInterface == false || 
      method.DeclaringType.Interfaces.None(i => i.IsEqual(overridden.DeclaringType))) 
     { 
      return false; 
     } 

     // check whether the type contains some other explicit implementation of the method 
     if (method.DeclaringType.Methods.SelectMany(m => m.Overrides).Any(m => m.IsEqual(overridden))) 
     { 
      // explicit implementation -> no implicit implementation possible 
      return false; 
     } 

     // now it is enough to just match the signatures and names: 
     return method.Name == overridden.Name && method.SignatureMatches(overridden); 
    } 

    static bool IsEqual(this MethodReference method1, MethodReference method2) 
    { 
     return method1.Name == method2.Name && method1.DeclaringType.IsEqual(method2.DeclaringType); 
    } 
    // IsEqual for TypeReference is similar... 
+0

可否請您提供缺少的`SignatureMatches`方法?這是一件複雜的事情,因爲它必須將通用參數和參數視爲不易比較的參數。 – ygoe 2015-11-06 19:55:34