为什么Microsoft.CSharp.RuntimeBinder.RuntimeBinderException如果有调用的方法？

Question

我有以下代码,它创建一个分配给smtpClient变量的动态对象.

public class TranferManager
{
    public void Tranfer(Account from, Account to, Money amount)
    {
        // Perform the required actions
        var smtpClient = New.SmtpClient();
        smtpClient.Send("info@bank.com", "from.Email", "Tranfer", "?");
        // In the previous line I get a Microsoft.CSharp.RuntimeBinder.RuntimeBinderException
        // with the description = "'object' does not contain a definition for 'Send'"
    }
}

public static class New
{
    public static dynamic SmtpClient(params object[] parameters)
    {
        return typeof(SmtpClient).New(parameters);
    }
}

public static class CreationExtensions
{
    private static Dictionary<Type, Func<object, dynamic>> builders =
        new Dictionary<Type, Func<object, dynamic>>();

    public static dynamic New(this Type type, params object[] parameters)
    {
        if(builders.ContainsKey(type))
            return builders[type](parameters);

        return Activator.CreateInstance(type, parameters);
    }

    public static void RegisterBuilder(this Type type, Func<object, dynamic> builder)
    {
        builders.Add(type, builder);
    }
}

为了测试它我使用UT(下面):

    [TestMethod()]
    public void TranferTest()
    {
        typeof(SmtpClient).RegisterBuilder(p => 
            new
            {
                Send = new Action<string, string, string, string>(
                (from, to, subject, body) => { })
            }
        );

        var tm = new TranferManager();
        tm.Tranfer(new Account(), new Account(), new Money());
        // Assert
    }

当我使用中间窗口时,请求我得到的smtpClient类型:

smtpClient.GetType()
{<>f__AnonymousType0`1[System.Action`4[System.String,System.String,System.String,System.String]]}

当我要求其成员时,我得到:

smtpClient.GetType().GetMembers()
{System.Reflection.MemberInfo[7]}
    [0]: {System.Action`4[System.String,System.String,System.String,System.String] get_Send()}
    [1]: {System.String ToString()}
    [2]: {Boolean Equals(System.Object)}
    [3]: {Int32 GetHashCode()}
    [4]: {System.Type GetType()}
    [5]: {Void .ctor(System.Action`4[System.String,System.String,System.String,System.String])}
    [6]: {System.Action`4[System.String,System.String,System.String,System.String] Send}

所以,我的问题是:为什么我得到那个例外？

Answer 1

匿名类型是内部的,如果跨组装边界dynamic无法解析属性.

不要使用匿名类型,请尝试使用实际类型或Expando对象.

Answer 2

在AssemblyInfo.cs中尝试添加以下内容:

[assembly: InternalsVisibleTo("NameSpace1.SubNameSpace1")]

其中NamsSpace1是您的项目名称,SubNameSpace是您的动态/匿名对象的名称空间