基本上,发生在静态
我尝试用最少的代码制作了一个小示例。下面的代码应该可以完整运行。
System.Linq.Expressions.Expression.Bind()
方法中的一些内部检查会提示“方法不是属性访问器”,而我的属性明显是一个属性。使用 Reflector,我已经最小化了引起问题的代码量,但我无论如何都想不出为什么会发生这种情况。我唯一的猜测是它可能与属性不在类本身上有关,但我认为这仍然应该可以工作:我尝试用最少的代码制作了一个小示例。下面的代码应该可以完整运行。
using System;
using System.Reflection;
public class Base
{
public virtual int Id { get; set; }
}
// As you can see, SubClass does not override the Id property of Base.
public class SubClass : Base { }
class Program
{
static void Main(string[] args)
{
// Getting the property directly from the type.
PropertyInfo propertyInfo = typeof(SubClass).GetProperty("Id");
MethodInfo setMethod = propertyInfo.GetSetMethod();
/* Code from here on out is from the System.Linq.Expressions.Bind() method (the one
that accepts a MethodInfo argument). This method causes GetProperty to be called
and retrieve what should be the same PropertyInfo. It fails here, saying something
along the lines of "Method is not a property accessor." which doesn't make sense. */
PropertyInfo propertyInfo2 = GetProperty(setMethod);
}
private static PropertyInfo GetProperty(MethodInfo mi)
{
// Not sure if it matters, but declaringType here is "Base".
Type declaringType = mi.DeclaringType;
BindingFlags bindingAttr = BindingFlags.NonPublic | BindingFlags.Public;
bindingAttr |= mi.IsStatic ? BindingFlags.Static : BindingFlags.Instance;
foreach (PropertyInfo info in declaringType.GetProperties(bindingAttr))
{
// For the "Id" property, info.CanRead is true, but CheckMethod is false.
if (info.CanRead && CheckMethod(mi, info.GetGetMethod(true)))
return info;
// For the "Id" property, info.CanWrite is true, but CheckMethod is false.
if (info.CanWrite && CheckMethod(mi, info.GetSetMethod(true)))
return info;
}
// This gets thrown after passing by the "Id" property that is the one I'm looking for.
throw new Exception("Method is not a property accessor");
}
private static bool CheckMethod(MethodInfo method, MethodInfo propertyMethod)
{
// These are not equal, so it goes to the next check. In the debugger, they appear identical when I look through the object tree.
if (method == propertyMethod)
return true;
Type declaringType = method.DeclaringType;
return ((declaringType.IsInterface && (method.Name == propertyMethod.Name)) && (declaringType.GetMethod(method.Name) == propertyMethod));
}
}
如果有人能帮忙我会非常感激!我现在很迷茫。
编辑 - 如果将typeof(SubClass)
替换为typeof(Base)
,它就能工作了,所以与这种关系有关。我想我可以通过创建一个扩展方法来解决问题,例如typeof(SubClass).GetPropertyFromActualClass("Id")
,但我不确定如何执行该检查。