两个.NET对象是相等的不说他们是 [英] Two .NET objects that are equal don't say they are

问题描述

我有以下代码：

object val1 = 1;
object val2 = 1;

bool result1 = (val1 == val2);//Equals false
bool result2 = val1.Equals(val2); //Equals true

什么回事？就是要解决这个问题去与.Equals（）方法的唯一途径？

What's up with that? Is the only way to fix this to go with .Equals() method?

推荐答案

运营商 = = 是静态的，不是虚拟的，所以问题是由静态类型，而不是运行类型确定。该的默认的实施 == 上引用类型的对象是比较引用（虽然类型可以实现不同的行为，例如字符串）。你有两个不同的对象和他们没有相同的引用，以便 == 返回false。

The operator == is static, not virtual, so the behaviour is determined by the static type and not the runtime type. The default implementation for == on objects of reference type is to compare the references (although types can implement a different behaviour, for example string). You have two different objects and they don't have the same reference so == returns false.

解决方案正如你指出的，是用等于。相当于是一个虚拟的方法。由于值1 的运行时类型的Int32 你最终调用的Int32.Equals 。从.net反射，你可以看到，这个实施如下：

The solution, as you point out, is to use Equals. Equals is a virtual method. Since value1 has runtime type Int32 you end up calling Int32.Equals. From .NET Reflector you can see that the implementation of this is as follows:

public override bool Equals(object obj)
{
    return ((obj is int) && (this == ((int) obj)));
}

在换句话说，它会检查参数类型是<$ C $的C> INT ，如果是将其转换并使用 == 这是对 INT 。这比较整数的值的

In other words, it checks if the argument is of type int, and if so casts it and uses the == that is defined for int. This compares the values of the integers.

时来解决这个问题去与.Equals（的唯一途径）方法？

Is the only way to fix this to go with .Equals() method?

另一种方法是投你的对象 INT ，然后使用 == ，就像 Int32.Equals 的实施一样。

An alternative is to cast your objects to int and then use ==, just as the implementation of Int32.Equals does.

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