字符串的行为.等于和==

昨天当我在这里张贴一个问题的答案时，我遇到了String.Equals和==在不同情况下表现不同的问题。

我想要得出String.Equals和==行为的结论。

bool result = false;
    object obj = "String"; 
    string str2 = "String";
    string str3 = typeof(string).Name;
    string str4 = "String";
    object obj2 = str3; 
    // obj, str2, str4 references are same.
    // obj is object type and others are string type
    // Comparision between object obj and string str2 -- Com 1
    result = String.Equals(obj, str2);// true
    result = String.ReferenceEquals(obj, str2); // true
    result = (obj == str2);// true
    // Comparision between object obj and string str3 -- Com 2
    result = String.Equals(obj, str3);// true
    result = String.ReferenceEquals(obj, str3); // false
    result = (obj == str3);// false
    // Comparision between object obj and string str4 -- Com 3
    result = String.Equals(obj, str4);// true
    result = String.ReferenceEquals(obj, str4); // true
    result = (obj == str4);// true
    // Comparision between string str2 and string str3 -- Com 4
    result = String.Equals(str2, str3);// true
    result = String.ReferenceEquals(str2, str3); // false
    result = (str2 == str3);// true
    // Comparision between string str2 and string str4 -- Com 5
    result = String.Equals(str2, str4);// true
    result = String.ReferenceEquals(str2, str4); // true
    result = (str2 == str4);// true
    // Comparision between string str3 and string str4 -- Com 6
    result = String.Equals(str3, str4);// true
    result = String.ReferenceEquals(str3, str4); // false
    result = (str3 == str4);// true
    // Comparision between object obj and object obj2 -- Com 7
    result = String.Equals(obj, obj2);// true
    result = String.ReferenceEquals(obj, obj2); // false
    result = (obj == obj2);// false

我看手表也

obj     "String" {1#}   object {string}
str2    "String" {1#}   string
str3    "String" {6#}   string
str4    "String" {1#}   string
obj2    "String" {6#}   object {string}

阅读这里和这里的文章

Com1, Com2, Com3, Com4, Com5和Com6为什么有不同的行为?