c# WCF 捕获基本类型的错误异常

Question

我到处寻找如何在 C# 中捕获基本错误契约类型。我想让我所有的错误契约都继承自一个类，并在 MVC Controller 中有一个 catch(FaultException fex)。

数据合约

[DataContract]
public class BaseClass1 
{ }

[DataContract]
public class Class2 : BaseClass1 
{ }

服务

[ServiceContract]
public interface IService1
{
    [OperationContract]
    [FaultContract(typeof(BaseClass1))]
    [FaultContract(typeof(Class2))]  //Do I need this one?
    void ThrowClass2();
}

public class Service1 : IService1
{
    public void ThrowClass2()
    {
        throw new FaultException<Class2>(new Class2(), "Class2 Reason");
    }
}

服务消费者

FaultTestService.Service1Client client = null;
try
{
    client = new FaultTestService.Service1Client();
    client.ThrowAmpFaults("InvalidParameter", 0);
}
catch (FaultException<Namespace.BaseClass1> fex)
{
    //DOES NOT GO IN HERE AS I WOULD EXPECT   
}
catch (FaultException fex)
{
    //Other Possible Option
    MessageFault fault = fex.CreateMessageFault();  
    var fe1 = fault.GetDetail<BaseClass1>();
    //This throws a serialization exception it needs <Class2>
}

请让我知道是否可以修复这些 catch 语句中的任何一个来完成我正在寻找的事情。

Answer 1

该语法在 C# 中不起作用。请考虑以下“解决方法”。

try
{
    throw new FaultException<DerivedClass2>(new DerivedClass2());
}
catch (FaultException fex)
{
    bool handled = false;
    Type fexType = fex.GetType();
    if (fexType.IsGenericType && fexType.GetGenericTypeDefinition() == typeof(FaultException<>))
    {
        if (typeof(BaseClass1).IsAssignableFrom(fexType.GetGenericArguments()[0]))
        {
            object detail = fexType.GetProperty("Detail").GetValue(fex, null);

            // Use detail here.

            handled = true;
        }
    }

    if (!handled)
        throw; // Don't know how to handle. Re-throw.
}

如果我们忽略 Detail == null 的不寻常情况，这可以简化但构造的泛型类型匹配。我还将使用 C# 动态关键字进一步简化它。

try
{
    throw new FaultException<DerivedClass2>(new DerivedClass2());
}
catch (FaultException fex)
{
    bool handled = false;
    Type fexType = fex.GetType();
    if (fexType.IsGenericType && fexType.GetGenericTypeDefinition() == typeof(FaultException<>))
    {
        object detail = ((dynamic)fex).Detail;
        if (detail is BaseClass1) // true for subclasses too!
        {
            // Use detail here.
        }

    }

    if (!handled)
        throw; // Don't know how to handle. Re-throw. 
}

要考虑的另一件事是您是否应该只使用 throw new FaultException<BaseClass1>(new DerivedClass2()) .这种抛出方式可以让您使用最初提供的代码进行捕获。