Private methods are closed? Use reflection to invoke a private method of an object.

When we learn C # The first set of keywords to contact may be Private, public, protect.

Private is defined as: methods and variables defined with this keyword can only be used inside an object.

But is this absolute? Is there a way to use private defined methods or variables in the caller's space?

Let's define one of the following classes:

2. Public class Testobj
4. {
6. Public string Publicvalue { get; set; }
8. Private string _privatevalue;
12. public Testobj ()
14. {
16. _privatevalue = "private";
18. Publicvalue = "public";
20. }
24. Public testobj (string value)
26. {
28. _privatevalue = "private_" + value;
30. Publicvalue = "public_" + value;
32. }
36. Private string returnprivatevalue ()
38. {
40. return _privatevalue;
42. }
44. }

So can we access _priavatevalue in this simple program?

1. Static void Main (string[] args)
2. {
3. Testobj to = new testobj ("test");
4. Console.WriteLine ("obj public parameter:{0}" to. Publicvalue);
5. Console.WriteLine ("obj public parameter:{0}", to. Returnprivatevalue ());
7. Console.read ();
8. }

We get a compile error when we try to compile this simple program.

' PrivateCallByReflection.testObj.returnPrivateValue () ' is inaccessible due to its protection level

So private is really safe, can only be accessed internally?

A little trick can get the results we want.

2. Static void Main (string[] args)
4. {
6. Testobj to = new testobj ("test");
8. Console.WriteLine ("obj public parameter:{0}" to. Publicvalue);
10. //console.writeline ("obj Public parameter:{0}", To.returnprivatevalue ());
14. MethodInfo Privatemethod = typeof(testobj). GetMethod ("returnprivatevalue", BindingFlags.Instance | BindingFlags.NonPublic);
16. Console.WriteLine ("obj Private method ' Returnprivatevalue ' return: {0}", Privatemethod.invoke (to, new Object[] {});
20. Console.read ();
22. }

Please note the underlined code.

Reflection helps us to access a private method.

No lower limit of reflection, really there is nothing to do .....

Private methods are closed? Use reflection to invoke a private method of an object.