在CIL（MSIL）中的Stringbuilder

Question

我想生成一個StringBuilder的代碼，並將一個類中的所有屬性的值寫入字符串。我有以下內容，但我目前在下面的代碼中收到「無效方法令牌」：

public static DynamicAccessor<T> CreateWriter(T target) //Target class to *serialize* 
    { 
     DynamicAccessor<T> dynAccessor = new DynamicAccessor<T>(); 

     MethodInfo AppendMethod = typeof(StringBuilder).GetMethod("Append", new[] { typeof(Object) }); //Append method of Stringbuilder 

     var method = new DynamicMethod("ClassWriter", typeof(StringBuilder), new[] { typeof(T) }, typeof(T), true); 
     var generator = method.GetILGenerator(); 
     LocalBuilder sb = generator.DeclareLocal(typeof(StringBuilder)); //sb pointer 


     generator.Emit(OpCodes.Newobj, typeof(StringBuilder)); //make our string builder 
     generator.Emit(OpCodes.Stloc, sb);      //make a pointer to our new sb 


     //iterate through all the instance of T's props and sb.Append their values. 
     PropertyInfo[] props = typeof(T).GetProperties(); 
     foreach (var info in props) 
     { 
      generator.Emit(OpCodes.Callvirt, info.GetGetMethod()); //call the Getter 
      generator.Emit(OpCodes.Ldloc, sb);      //load the sb pointer 
      generator.Emit(OpCodes.Callvirt, AppendMethod);  //Call Append 
     } 

     generator.Emit(OpCodes.Ldloc, sb); 
     generator.Emit(OpCodes.Ret);   //return pointer to sb 

     dynAccessor.WriteHandler = method.CreateDelegate(typeof(Write)) as Write; 
     return dynAccessor; 
    } 

有沒有想法？ 在此先感謝:)

Answer 1

任何屬性值類型（int等）將需要裝箱;或者您將需要使用不同的Append過載。

另外：

• 需要加載的對象的每個時間（爲arg0）
• StringBuilder.Append是一個流利API;您可能需要彈出的值，或再使用它：
• 因此，你不需要現場

（個人，不過，我會返回一個string，但「咩」 ）

像這樣：

DynamicAccessor<T> dynAccessor = new DynamicAccessor<T>(); 
    MethodInfo AppendMethod = typeof(StringBuilder).GetMethod("Append", new[] { typeof(Object) }); //Append method of Stringbuilder 

    var method = new DynamicMethod("ClassWriter", typeof(StringBuilder), new[] { typeof(T) }, typeof(T), true); 
    var generator = method.GetILGenerator(); 
    generator.Emit(OpCodes.Newobj, typeof(StringBuilder).GetConstructor(Type.EmptyTypes)); //make our string builder 
    //iterate through all the instance of T's props and sb.Append their values. 
    PropertyInfo[] props = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance); 
    foreach (var info in props) 
    { 
     generator.Emit(OpCodes.Ldarg_0); 
     generator.Emit(OpCodes.Callvirt, info.GetGetMethod()); //call the Getter 
     if (info.PropertyType.IsValueType) 
     { 
      generator.Emit(OpCodes.Box, info.PropertyType); 
     } 
     generator.Emit(OpCodes.Callvirt, AppendMethod);  //Call Append 
    } 
    generator.Emit(OpCodes.Ret);   //return pointer to sb 

這將生成等價於：

StringBuilder ClassWriter(T obj) { 
    return new StringBuilder.Append((object)obj.Foo).Append((object)obj.Bar) 
        .Append((object)obj.Blip).Append((object)obj.Blap); 
}