为空的类型入门类型定义打破了非可空类型

Question

此代码是一个后续问题以下，如果你想看到：Parse to Nullable Enum

Type t = currentProperty.PropertyType; 
if (t.GetGenericTypeDefinition() == typeof(Nullable<>)) 
    t = t.GetGenericArguments().First(); 

我上线＃2得到一个错误这是IF声明。

System.Reflection.TargetInvocationException : Exception has been thrown by the 
target of an invocation. ----> System.InvalidOperationException : This operation 
is only valid on generic types. 
at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor) 
at System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) 
at System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes) 
at System.Activator.CreateInstance(Type type, Object[] args) 

如何在执行IF语句中的代码之前测试该条件？

Answer 1

Here is the MSDN documentation on checking for nullable types

它看起来像你需要添加以下内容：

if(t.IsGenericType && ...