在c＃中获取所有枚举值的简便方法

Question

I've tried a little Program... I want to run a program and see all method names in c# class... Here is the code

class Program
{
    public int adf()
    {
        return 0;
    }
    static void Main(string[] args)
    {

        foreach (MethodInfo mInfo in typeof(Program).GetMethods(BindingFlags.NonPublic | BindingFlags.DeclaredOnly | BindingFlags.Public | BindingFlags.Instance | BindingFlags.Static))
        {
            Console.WriteLine(mInfo.Name);
        }
       Console.ReadKey();
    }
    private void bdf()
    {
        Console.WriteLine("Dg");
    }
}

It's work fine, in result I've got this

 adf
 main
 bdf

Now , I want to pass to GetMethods function only one parameter and get result... I don't think it's a good way to pass 5 parameters with 'binary or(|)' ... In BindingFlags Enum is 19 fields and what it will be if I want to pass 18 parameters xD How can I do it passing only one value?

Here Is Enum

 public enum BindingFlags
{
    Default = 0,
    IgnoreCase = 1,
    DeclaredOnly = 2,
    Instance = 4,
    Static = 8,
    Public = 16,
    NonPublic = 32,
    FlattenHierarchy = 64,
    InvokeMethod = 256,
    CreateInstance = 512,
    GetField = 1024,
    SetField = 2048,
    GetProperty = 4096,
    SetProperty = 8192,
    PutDispProperty = 16384,
    PutRefDispProperty = 32768,
    ExactBinding = 65536,
    SuppressChangeType = 131072,
    OptionalParamBinding = 262144,
    IgnoreReturn = 16777216,
  }
}

I think it's very interesting and helpful question...

Answer 1

Code below should get a value containing all flags (could easily be made into a generic method), you can then do AllFlags & ~FlagToRemove to get all but one flag.

AllFlags = (EnumFlagType)Enum.GetValues(typeof(EnumFlagType))
                             .Cast<int>().Aggregate((acc, next) => acc | next);

---

[Flags]
enum TestEnum { one = 1, two = 2, three = 4, four = 8 };

void Main()
{

    var AllFlags = (TestEnum)Enum.GetValues(typeof(TestEnum))
                             .Cast<int>().Aggregate((acc, next) => acc | next);

    Console.WriteLine(AllFlags); // Prints "one, two, three, four"

    Console.WriteLine(AllFlags & ~two); // Prints "one, three, four"
}

Answer 2

Pay attantion at the body of BindingFlags enumeration, all the values are power of 2. So binary or just calculates sum of provided integer values. In order to pass all flags just send the sum of all int values. In order to pass only some values just send binary integer with 1 in the corresponding position of the flag which needs to be passed. Please see code below.

BindingFlags flag = (BindingFlags)Convert.ToInt32("0000010010000101010", 2)

for your example must be

BindingFlags flag = (BindingFlags)Convert.ToInt32("111110", 2)

and when we print the flag we have a

DeclaredOnly, Instance, Static, Public, NonPublic

and you can get metods

            Type t = typeof(Program);
            MethodInfo[] mi = t.GetMethods(flag);

You right, it is a really interesting question.

Answer 3

Write static method:

public static class BindingFlagsHelper
{
    public static BindingFlags GetAllMethods()
    {
        return 
            BindingFlags.NonPublic | 
            BindingFlags.DeclaredOnly | 
            BindingFlags.Public | 
            BindingFlags.Instance | BindingFlags.Static;
    }
}

Answer 4

You can use a variable to hold the interesting flags and pass that through:

BindingFlags myFlags = BindingFlags.NonPublic | BindingFlags.DeclaredOnly | BindingFlags.Public | BindingFlags.Instance | BindingFlags.Static;

foreach (MethodInfo mInfo in typeof(Program).GetMethods(myFlags))
{
     Console.WriteLine(mInfo.Name);
}

Answer 5

You won't be passing 5 parameters, you'll be passing only one int when the bitwise or s are done executing, you could put unlimited flags and '|' them and only one sizeof(int) parameter will be passed. You could make precomputed values with

const int my_val = flag_1|flag_3|flag_5;