c# - 从非静态类访问静态方法可能在 java 而不是在 c# 中

Question

从带有对象的非静态类访问静态方法。 这在 C# 中是不可能的。由JAVA完成的地方。 它是如何工作的？

java的例子

/**
* Access static member of the class through object.
*/
import java.io.*;

class StaticMemberClass {
    // Declare a static method.
    public static void staticDisplay() {
        System.out.println("This is static method.");
    }
    // Declare a non static method.
    public void nonStaticDisplay() {
        System.out.println("This is non static method.");
    }
}

class StaticAccessByObject {

    public static void main(String[] args) throws IOException {
        // call a static member only by class name.
        StaticMemberClass.staticDisplay();
        // Create object of StaticMemberClass class.
        StaticMemberClass obj = new StaticMemberClass();
        // call a static member only by object.
        obj.staticDisplay();
        // accessing non static method through object.
        obj.nonStaticDisplay();
    }
}

程序输出:

This is static method.
This is static method.
This is non static method.

如何在 C# 中执行此操作？ 提前致谢..

Answer 1

C# 禁止通过instance.Method 引用静态方法，只有Type.Method 是可以接受的。要调用静态方法，您需要遍历类型，而不是实例。
在您的情况下，这意味着 StaticMemberClass.staticDisplay() 有效，但 obj.staticDisplay() 无效。

---

When a method is referenced in a member-access (§7.6.4) of the form E.M, if M is a static method, E must denote a type containing M, and if M is an instance method, E must denote an instance of a type containing M.

(C# 语言规范版本 4.0 - 10.6.2 静态和实例方法)

When a static member M is referenced in a member-access (§7.6.4) of the form E.M, E must denote a type containing M. It is a compile-time error for E to denote an instance.

(C# 语言规范版本 4.0 - 10.3.7 静态和实例成员)