当比较对象引用和字符串时(即使对象引用引用了字符串)，特定于字符串类的==操作符的特殊行为将被忽略。

Normally (when not dealing with strings, that is), Equals compares values, while == compares object references. If two objects you are comparing are referring to the same exact instance of an object, then both will return true, but if one has the same content and came from a different source (is a separate instance with the same data), only Equals will return true. However, as noted in the comments, string is a special case because it overrides the == operator so that when dealing purely with string references (and not object references), only the values are compared even if they are separate instances. The following code illustrates the subtle differences in behaviors:

string s1 = "test";
string s2 = "test";
string s3 = "test1".Substring(0, 4);
object s4 = s3;  // Notice: set to object variable!

Console.WriteLine($"{object.ReferenceEquals(s1, s2)} {s1 == s2} {s1.Equals(s2)}");
Console.WriteLine($"{object.ReferenceEquals(s1, s3)} {s1 == s3} {s1.Equals(s3)}");
Console.WriteLine($"{object.ReferenceEquals(s1, s4)} {s1 == s4} {s1.Equals(s4)}");

输出结果为:

True True True     // s1, s2
False True True    // s1, s3
False False True   // s1, s4

简介:

= =操作符

如果操作数为值类型且值相等，则返回true否则为false。 如果操作数是引用类型(string除外)，并且都引用同一个实例(同一对象)，则返回true否则返回false。 如果操作数为字符串类型且值相等，则返回true否则返回false。

.Equals

如果操作数是引用类型，它执行引用相等，即如果两个操作数都引用同一个实例(同一个对象)，则返回true否则返回false。 如果操作数是值类型，那么与==运算符不同，它首先检查它们的类型，如果它们的类型相同，它执行==运算符，否则返回false。

我想补充的是，如果你将对象转换为字符串，那么它将正确工作。这就是为什么编译器会给你一个警告说:

可能出现意外的参考比较;为了进行价值比较， 转换左侧以输入'string'

注意，在c#中有两种不同类型的等式

1-值相等(对于int, DateTime和struct等值类型)

2-引用平等(对象)

有两个基本的标准协议来实现相等性检查。

1- ==和!=运算符。

2- virtual Equals方法。

==和!=是静态解析的，这意味着c#将在编译时决定哪种类型将执行比较。

例如值类型

 int x = 50;
 int y = 50;
 Console.WriteLine (x == y); // True

但是对于参考类型

 object x = 50;
 object y = 50;
 Console.WriteLine (x == y); // False 

Equals()最初在运行时根据操作数的实际类型解析。

例如，在下面的例子中，在运行时，将决定Equals()将应用于int值，结果为真。

object x = 5;
object y = 5;
Console.WriteLine (x.Equals (y)); // True

但是，对于引用类型，它将使用引用相等性检查。

MyObject x = new MyObject();
MyObject y = x;
Console.WriteLine (x.Equals (y)); // True

注意Equals()对struct使用结构比较，这意味着它对struct的每个字段调用Equals。

I am a bit confused here. If the runtime type of Content is of type string, then both == and Equals should return true. However, since this does not appear to be the case, then runtime type of Content is not string and calling Equals on it is doing a referential equality and this explains why Equals("Energy Attack") fails. However, in the second case, the decision as to which overloaded == static operator should be called is made at compile time and this decision appears to be ==(string,string). this suggests to me that Content provides an implicit conversion to string.

给答案再加一分。

. equalsto()方法提供了比较区域性和区分大小写的方法。