Re: IBatisNet - HashCodeProvider.GetIdentityHashCode

[Ron Grabowski]

Why is CacheKey.Update(object) using obj.GetHasCode()? Won't that call the 
overriden GetHashCode method if its overriden? Is that a BadIdea? Should it be:

public CacheKey Update(object obj) 
{
 int baseHashCode = HashCodeProvider.GetIdentityHashCode(obj);
 ...

----- Original Message ----
From: Ron Grabowski <[EMAIL PROTECTED]>
To: dev@ibatis.apache.org
Sent: Thursday, September 28, 2006 12:25:53 AM
Subject: IBatisNet - HashCodeProvider.GetIdentityHashCode

public static int GetIdentityHashCode(object obj)
{
 System.Reflection.MethodInfo methodInfo = null;
 Type type = typeof(object);
 methodInfo = type.GetMethod("GetHashCode");
 return (int) methodInfo.Invoke(obj, null);
}

Why can't we call:

public static int GetIdentityHashCode(object obj)
{
 return obj.GetHashCode();
}

Does using reflection call the framework's GetHashCode method even if the 
object has overriden it?

Can we cache the MethodInfo?

public class HashCodeProvider
{
 private static MethodInfo getHashCodeMethodInfo = null;

 static HashCodeProvider()
 {
  Type type = typeof(object);
  getHashCodeMethodInfo = type.GetMethod("GetHashCode");
 }

 public static int GetIdentityHashCode(object obj)
 {
  return (int)getHashCodeMethodInfo.Invoke(obj, null);
 }
}