BindingFlags BindingFlags BindingFlags BindingFlags Enum

Definition

Specifies flags that control binding and the way in which the search for members and types is conducted by reflection.

This enumeration has a FlagsAttribute attribute that allows a bitwise combination of its member values.

public enum class BindingFlags
[System.Flags]
[System.Runtime.InteropServices.ComVisible(true)]
public enum BindingFlags
type BindingFlags = 
Public Enum BindingFlags
Inheritance
Attributes

Fields

CreateInstance CreateInstance CreateInstance CreateInstance 512

Specifies that reflection should create an instance of the specified type. Calls the constructor that matches the given arguments. The supplied member name is ignored. If the type of lookup is not specified, (Instance | Public) will apply. It is not possible to call a type initializer.

This flag is passed to an InvokeMember method to invoke a constructor.

DeclaredOnly DeclaredOnly DeclaredOnly DeclaredOnly 2

Specifies that only members declared at the level of the supplied type's hierarchy should be considered. Inherited members are not considered.

Default Default Default Default 0

Specifies that no binding flags are defined.

DoNotWrapExceptions DoNotWrapExceptions DoNotWrapExceptions DoNotWrapExceptions 33554432
ExactBinding ExactBinding ExactBinding ExactBinding 65536

Specifies that types of the supplied arguments must exactly match the types of the corresponding formal parameters. Reflection throws an exception if the caller supplies a non-null Binder object, since that implies that the caller is supplying BindToXXX implementations that will pick the appropriate method.

FlattenHierarchy FlattenHierarchy FlattenHierarchy FlattenHierarchy 64

Specifies that public and protected static members up the hierarchy should be returned. Private static members in inherited classes are not returned. Static members include fields, methods, events, and properties. Nested types are not returned.

GetField GetField GetField GetField 1024

Specifies that the value of the specified field should be returned.

This flag is passed to an InvokeMember method to get a field value.

GetProperty GetProperty GetProperty GetProperty 4096

Specifies that the value of the specified property should be returned.

This flag is passed to an InvokeMember method to invoke a property getter.

IgnoreCase IgnoreCase IgnoreCase IgnoreCase 1

Specifies that the case of the member name should not be considered when binding.

IgnoreReturn IgnoreReturn IgnoreReturn IgnoreReturn 16777216

Used in COM interop to specify that the return value of the member can be ignored.

Instance Instance Instance Instance 4

Specifies that instance members are to be included in the search.

InvokeMethod InvokeMethod InvokeMethod InvokeMethod 256

Specifies that a method is to be invoked. This must not be a constructor or a type initializer.

This flag is passed to an InvokeMember method to invoke a method.

NonPublic NonPublic NonPublic NonPublic 32

Specifies that non-public members are to be included in the search.

OptionalParamBinding OptionalParamBinding OptionalParamBinding OptionalParamBinding 262144

Returns the set of members whose parameter count matches the number of supplied arguments. This binding flag is used for methods with parameters that have default values and methods with variable arguments (varargs). This flag should only be used with InvokeMember(String, BindingFlags, Binder, Object, Object[], ParameterModifier[], CultureInfo, String[]).

Public Public Public Public 16

Specifies that public members are to be included in the search.

PutDispProperty PutDispProperty PutDispProperty PutDispProperty 16384

Specifies that the PROPPUT member on a COM object should be invoked. PROPPUT specifies a property-setting function that uses a value. Use PutDispProperty if a property has both PROPPUT and PROPPUTREF and you need to distinguish which one is called.

PutRefDispProperty PutRefDispProperty PutRefDispProperty PutRefDispProperty 32768

Specifies that the PROPPUTREF member on a COM object should be invoked. PROPPUTREF specifies a property-setting function that uses a reference instead of a value. Use PutRefDispProperty if a property has both PROPPUT and PROPPUTREF and you need to distinguish which one is called.

SetField SetField SetField SetField 2048

Specifies that the value of the specified field should be set.

This flag is passed to an InvokeMember method to set a field value.

SetProperty SetProperty SetProperty SetProperty 8192

Specifies that the value of the specified property should be set. For COM properties, specifying this binding flag is equivalent to specifying PutDispProperty and PutRefDispProperty.

This flag is passed to an InvokeMember method to invoke a property setter.

Static Static Static Static 8

Specifies that static members are to be included in the search.

SuppressChangeType SuppressChangeType SuppressChangeType SuppressChangeType 131072

Not implemented.

Examples

The following example demonstrates many of the binding flags.

using namespace System;
using namespace System::Collections;
using namespace System::Reflection;
using namespace System::IO;

//namespace BindingFlagsSnippet {
public ref class TestClass
{
public:
   String^ Name;

private:
   array<Object^>^ values;
   int methodCalled;

public:

   property Object^ Item [int]
   {
      Object^ get( int index )
      {
         return values[ index ];
      }

      void set( int index, Object^ value )
      {
         values[ index ] = value;
      }
   }

   property Object^ Value
   {
      Object^ get()
      {
         return "the value";
      }
   }

   TestClass() 
   {
      Name = "initialName";
      values = gcnew array<Object^> {(int^)0,1,2,3,4,5,6,7,8,9};
      methodCalled = 0;
   }
   
   TestClass(String^ initName)
   {
      Name = initName;
      values = gcnew array<Object^> {(int^)0,1,2,3,4,5,6,7,8,9};
      methodCalled = 0;
   }

   static void SayHello()
   {
      Console::WriteLine( "Hello" );
   }

   void AddUp()
   {
      methodCalled++;
      Console::WriteLine( "AddUp Called {0} times", methodCalled );
   }

   static double ComputeSum( double d1, double d2 )
   {
      return d1 + d2;
   }

   static void PrintName( String^ firstName, String^ lastName )
   {
      Console::WriteLine( "{0},{1}", lastName, firstName );
   }

   void PrintTime()
   {
      Console::WriteLine( DateTime::Now );
   }

   void Swap( interior_ptr<int> a, interior_ptr<int> b )
   {
      int x =  *a;
       *a =  *b;
       *b = x;
   }
};


[DefaultMemberAttribute("PrintTime")]
public ref class TestClass2
{
public:
   void PrintTime()
   {
      Console::WriteLine( DateTime::Now );
   }

};

public ref class Base
{
private:
    static int BaseOnlyPrivate = 0;
protected:
    static int BaseOnly = 0;
};

public ref class Derived : Base
{
public:
    static int DerivedOnly = 0;
};

public ref class MostDerived : Derived {};

void main()
{
   array<Object^>^ noArguments;

   // BindingFlags::InvokeMethod
   // Call a static method.
   Type^ t = TestClass::typeid;
   Console::WriteLine();
   Console::WriteLine( "Invoking a static method." );
   Console::WriteLine( "-------------------------" );
   t->InvokeMember( "SayHello", BindingFlags::InvokeMethod | BindingFlags::Public | BindingFlags::Static, 
         nullptr, nullptr, noArguments );

   // BindingFlags::InvokeMethod
   // Call an instance method.
   TestClass^ c = gcnew TestClass;
   Console::WriteLine();
   Console::WriteLine( "Invoking an instance method." );
   Console::WriteLine( "----------------------------" );
   c->GetType()->InvokeMember( "AddUp", BindingFlags::InvokeMethod, nullptr, c, noArguments );
   c->GetType()->InvokeMember( "AddUp", BindingFlags::InvokeMethod, nullptr, c, noArguments );

   // BindingFlags::InvokeMethod
   // Call a method with parameters.
   array<Object^>^args = {100.09,184.45};
   Object^ result;
   Console::WriteLine();
   Console::WriteLine( "Invoking a method with parameters." );
   Console::WriteLine( "---------------------------------" );
   result = t->InvokeMember( "ComputeSum", BindingFlags::InvokeMethod, nullptr, nullptr, args );
   Console::WriteLine( " {0} + {1} = {2}", args[ 0 ], args[ 1 ], result );

   // BindingFlags::GetField, SetField
   Console::WriteLine();
   Console::WriteLine( "Invoking a field (getting and setting.)" );
   Console::WriteLine( "--------------------------------------" );

   // Get a field value.
   result = t->InvokeMember( "Name", BindingFlags::GetField, nullptr, c, noArguments );
   Console::WriteLine( "Name == {0}", result );

   // Set a field.
   array<Object^>^obj2 = {"NewName"};
   t->InvokeMember( "Name", BindingFlags::SetField, nullptr, c, obj2 );
   result = t->InvokeMember( "Name", BindingFlags::GetField, nullptr, c, noArguments );
   Console::WriteLine( "Name == {0}", result );
   Console::WriteLine();
   Console::WriteLine( "Invoking an indexed property (getting and setting.)" );
   Console::WriteLine( "--------------------------------------------------" );

   // BindingFlags::GetProperty
   // Get an indexed property value.
   int index = 3;
   array<Object^>^obj3 = {index};
   result = t->InvokeMember( "Item", BindingFlags::GetProperty, nullptr, c, obj3 );
   Console::WriteLine( "Item->Item[ {0}] == {1}", index, result );

   // BindingFlags::SetProperty
   // Set an indexed property value.
   index = 3;
   array<Object^>^obj4 = {index,"NewValue"};
   t->InvokeMember( "Item", BindingFlags::SetProperty, nullptr, c, obj4 );
   result = t->InvokeMember( "Item", BindingFlags::GetProperty, nullptr, c, obj3 );
   Console::WriteLine( "Item->Item[ {0}] == {1}", index, result );
   Console::WriteLine();
   Console::WriteLine( "Getting a field or property." );
   Console::WriteLine( "----------------------------" );

   // BindingFlags::GetField
   // Get a field or property.
   result = t->InvokeMember( "Name", static_cast<BindingFlags>(BindingFlags::GetField | 
       BindingFlags::GetProperty), nullptr, c, noArguments );
   Console::WriteLine( "Name == {0}", result );

   // BindingFlags::GetProperty
   result = t->InvokeMember( "Value", static_cast<BindingFlags>(BindingFlags::GetField | 
       BindingFlags::GetProperty), nullptr, c, noArguments );
   Console::WriteLine( "Value == {0}", result );
   Console::WriteLine();
   Console::WriteLine( "Invoking a method with named parameters." );
   Console::WriteLine( "---------------------------------------" );

   // BindingFlags::InvokeMethod
   // Call a method using named parameters.
   array<Object^>^argValues = {"Mouse","Micky"};
   array<String^>^argNames = {"lastName","firstName"};
   t->InvokeMember( "PrintName", BindingFlags::InvokeMethod, nullptr, nullptr, argValues, nullptr, 
       nullptr, argNames );
   Console::WriteLine();
   Console::WriteLine( "Invoking a default member of a type." );
   Console::WriteLine( "------------------------------------" );

   // BindingFlags::Default
   // Call the default member of a type.
   Type^ t3 = TestClass2::typeid;
   t3->InvokeMember( "", static_cast<BindingFlags>(BindingFlags::InvokeMethod | BindingFlags::Default), 
        nullptr, gcnew TestClass2, noArguments );

   // BindingFlags::Static, NonPublic, and Public
   // Invoking a member with ref parameters.
   Console::WriteLine();
   Console::WriteLine( "Invoking a method with ref parameters." );
   Console::WriteLine( "--------------------------------------" );
   MethodInfo^ m = t->GetMethod( "Swap" );
   args = gcnew array<Object^>(2);
   args[ 0 ] = 1;
   args[ 1 ] = 2;
   m->Invoke( gcnew TestClass, args );
   Console::WriteLine( "{0}, {1}", args[ 0 ], args[ 1 ] );

   // BindingFlags::CreateInstance
   // Creating an instance with a parameterless constructor.
   Console::WriteLine();
   Console::WriteLine( "Creating an instance with a parameterless constructor." );
   Console::WriteLine( "------------------------------------------------------" );
   Object^ obj = t->InvokeMember( "TestClass", static_cast<BindingFlags>(BindingFlags::Public | 
       BindingFlags::Instance | BindingFlags::CreateInstance), nullptr, nullptr, noArguments );
   Console::WriteLine("Instance of {0} created.", obj->GetType()->Name);

   // Creating an instance with a constructor that has parameters.
   Console::WriteLine();
   Console::WriteLine( "Creating an instance with a constructor that has parameters." );
   Console::WriteLine( "------------------------------------------------------------" );
   obj = t->InvokeMember( "TestClass", static_cast<BindingFlags>(BindingFlags::Public | 
       BindingFlags::Instance | BindingFlags::CreateInstance), nullptr, nullptr, 
       gcnew array<Object^> { "Hello, World!" } );
   Console::WriteLine("Instance of {0} created with initial value '{1}'.", obj->GetType()->Name, 
       obj->GetType()->InvokeMember("Name", BindingFlags::GetField, nullptr, obj, noArguments));

   // BindingFlags::DeclaredOnly
   Console::WriteLine();
   Console::WriteLine( "DeclaredOnly instance members." );
   Console::WriteLine( "------------------------------" );
   array<System::Reflection::MemberInfo^>^memInfo = t->GetMembers( BindingFlags::DeclaredOnly | 
       BindingFlags::Instance | BindingFlags::Public);
   for ( int i = 0; i < memInfo->Length; i++ )
   {
      Console::WriteLine( memInfo[ i ]->Name );

   }

   // BindingFlags::IgnoreCase
   Console::WriteLine();
   Console::WriteLine( "Using IgnoreCase and invoking the PrintName method." );
   Console::WriteLine( "---------------------------------------------------" );
   t->InvokeMember( "printname", static_cast<BindingFlags>(BindingFlags::IgnoreCase | 
                BindingFlags::Static | BindingFlags::Public | BindingFlags::InvokeMethod), 
                nullptr, nullptr, gcnew array<Object^> {"Brad","Smith"});

   // BindingFlags::FlattenHierarchy
   Console::WriteLine();
   Console::WriteLine( "Using FlattenHierarchy to get inherited static protected and public members." );
   Console::WriteLine( "----------------------------------------------------------------------------" );
   array<FieldInfo^>^ finfos = MostDerived::typeid->GetFields(BindingFlags::NonPublic | 
         BindingFlags::Public | BindingFlags::Static | BindingFlags::FlattenHierarchy);
   for each (FieldInfo^ finfo in finfos)
   {
       Console::WriteLine("{0} defined in {1}.", finfo->Name, finfo->DeclaringType->Name);
   }

   Console::WriteLine();
   Console::WriteLine("Without FlattenHierarchy." );
   Console::WriteLine("-------------------------");
   finfos = MostDerived::typeid->GetFields(BindingFlags::NonPublic | BindingFlags::Public |
         BindingFlags::Static);
   for each (FieldInfo^ finfo in finfos)
   {
       Console::WriteLine("{0} defined in {1}.", finfo->Name, finfo->DeclaringType->Name);
   }
};

/* This example produces output similar to the following:

Invoking a static method.
-------------------------
Hello

Invoking an instance method.
----------------------------
AddUp Called 1 times
AddUp Called 2 times

Invoking a method with parameters.
---------------------------------
 100.09 + 184.45 = 284.54

Invoking a field (getting and setting.)
--------------------------------------
Name == initialName
Name == NewName

Invoking an indexed property (getting and setting.)
--------------------------------------------------
Item->Item[ 3] == 3
Item->Item[ 3] == NewValue

Getting a field or property.
----------------------------
Name == NewName
Value == the value

Invoking a method with named parameters.
---------------------------------------
Mouse,Micky

Invoking a default member of a type.
------------------------------------
12/23/2009 4:19:06 PM

Invoking a method with ref parameters.
--------------------------------------
2, 1

Creating an instance with a parameterless constructor.
------------------------------------------------------
Instance of TestClass created.

Creating an instance with a constructor that has parameters.
------------------------------------------------------------
Instance of TestClass created with initial value 'Hello, World!'.

DeclaredOnly instance members.
------------------------------
get_Item
set_Item
get_Value
AddUp
PrintTime
Swap
.ctor
.ctor
Value
Item
Name
methodCalled

Using IgnoreCase and invoking the PrintName method.
---------------------------------------------------
Smith,Brad

Using FlattenHierarchy to get inherited static protected and public members.
----------------------------------------------------------------------------
DerivedOnly defined in Derived.
BaseOnly defined in Base.

Without FlattenHierarchy.
-------------------------

 */
using System;
using System.Reflection;
using System.IO;

namespace BindingFlagsSnippet
{
    class Example
    {
        static void Main()
        {
            // BindingFlags.InvokeMethod
            // Call a static method.
            Type t = typeof (TestClass);

            Console.WriteLine();
            Console.WriteLine("Invoking a static method.");
            Console.WriteLine("-------------------------");
            t.InvokeMember ("SayHello", BindingFlags.InvokeMethod | BindingFlags.Public | 
                BindingFlags.Static, null, null, new object [] {});

            // BindingFlags.InvokeMethod
            // Call an instance method.
            TestClass c = new TestClass ();
            Console.WriteLine();
            Console.WriteLine("Invoking an instance method.");
            Console.WriteLine("----------------------------");
            c.GetType().InvokeMember ("AddUp", BindingFlags.InvokeMethod, null, c, new object [] {});
            c.GetType().InvokeMember ("AddUp", BindingFlags.InvokeMethod, null, c, new object [] {});

            // BindingFlags.InvokeMethod
            // Call a method with parameters.
            object [] args = new object [] {100.09, 184.45};
            object result;
            Console.WriteLine();
            Console.WriteLine("Invoking a method with parameters.");
            Console.WriteLine("---------------------------------");
            result = t.InvokeMember ("ComputeSum", BindingFlags.InvokeMethod, null, null, args);
            Console.WriteLine ("{0} + {1} = {2}", args[0], args[1], result);

            // BindingFlags.GetField, SetField
            Console.WriteLine();
            Console.WriteLine("Invoking a field (getting and setting.)");
            Console.WriteLine("--------------------------------------");
            // Get a field value.
            result = t.InvokeMember ("Name", BindingFlags.GetField, null, c, new object [] {});
            Console.WriteLine ("Name == {0}", result);
            // Set a field.
            t.InvokeMember ("Name", BindingFlags.SetField, null, c, new object [] {"NewName"});
            result = t.InvokeMember ("Name", BindingFlags.GetField, null, c, new object [] {});
            Console.WriteLine ("Name == {0}", result);

            Console.WriteLine();
            Console.WriteLine("Invoking an indexed property (getting and setting.)");
            Console.WriteLine("--------------------------------------------------");
            // BindingFlags.GetProperty
            // Get an indexed property value.
            int  index = 3;
            result = t.InvokeMember ("Item", BindingFlags.GetProperty, null, c, new object [] {index});
            Console.WriteLine ("Item[{0}] == {1}", index, result);
            // BindingFlags.SetProperty
            // Set an indexed property value.
            index = 3;
            t.InvokeMember ("Item", BindingFlags.SetProperty, null, c, new object [] {index, "NewValue"});
            result = t.InvokeMember ("Item", BindingFlags.GetProperty , null, c, new object [] {index});
            Console.WriteLine ("Item[{0}] == {1}", index, result);

            Console.WriteLine();
            Console.WriteLine("Getting a field or property.");
            Console.WriteLine("----------------------------");
            // BindingFlags.GetField
            // Get a field or property.
            result = t.InvokeMember ("Name", BindingFlags.GetField | BindingFlags.GetProperty, null, c, 
                new object [] {});
            Console.WriteLine ("Name == {0}", result);
            // BindingFlags.GetProperty
            result = t.InvokeMember ("Value", BindingFlags.GetField | BindingFlags.GetProperty, null, c, 
                new object [] {});
            Console.WriteLine ("Value == {0}", result);

            Console.WriteLine();
            Console.WriteLine("Invoking a method with named parameters.");
            Console.WriteLine("---------------------------------------");
            // BindingFlags.InvokeMethod
            // Call a method using named parameters.
            object[] argValues = new object [] {"Mouse", "Micky"};
            String [] argNames = new String [] {"lastName", "firstName"};
            t.InvokeMember ("PrintName", BindingFlags.InvokeMethod, null, null, argValues, null, null, 
                argNames);

            Console.WriteLine();
            Console.WriteLine("Invoking a default member of a type.");
            Console.WriteLine("------------------------------------");
            // BindingFlags.Default
            // Call the default member of a type.
            Type t3 = typeof (TestClass2);
            t3.InvokeMember ("", BindingFlags.InvokeMethod | BindingFlags.Default, null, new TestClass2(), 
                new object [] {});

            // BindingFlags.Static, NonPublic, and Public
            // Invoking a member with ref parameters.
            Console.WriteLine();
            Console.WriteLine("Invoking a method with ref parameters.");
            Console.WriteLine("--------------------------------------");
            MethodInfo m = t.GetMethod("Swap");
            args = new object[2];
            args[0] = 1;
            args[1] = 2;
            m.Invoke(new TestClass(),args);
            Console.WriteLine ("{0}, {1}", args[0], args[1]);

            // BindingFlags.CreateInstance
            // Creating an instance with a parameterless constructor.
            Console.WriteLine();
            Console.WriteLine("Creating an instance with a parameterless constructor.");
            Console.WriteLine("------------------------------------------------------");
            object cobj = t.InvokeMember ("TestClass", BindingFlags.Public |
                BindingFlags.Instance | BindingFlags.CreateInstance,
                null, null, new object [] {});
            Console.WriteLine("Instance of {0} created.", cobj.GetType().Name);

            // Creating an instance with a constructor that has parameters.
            Console.WriteLine();
            Console.WriteLine("Creating an instance with a constructor that has parameters.");
            Console.WriteLine("------------------------------------------------------------");
            cobj = t.InvokeMember ("TestClass", BindingFlags.Public |
                BindingFlags.Instance | BindingFlags.CreateInstance,
                null, null, new object [] { "Hello, World!" });
            Console.WriteLine("Instance of {0} created with initial value '{1}'.", cobj.GetType().Name,
                cobj.GetType().InvokeMember("Name", BindingFlags.GetField, null, cobj, null));

            // BindingFlags.DeclaredOnly
            Console.WriteLine();
            Console.WriteLine("DeclaredOnly instance members.");
            Console.WriteLine("------------------------------");
            System.Reflection.MemberInfo[] memInfo =
                t.GetMembers(BindingFlags.DeclaredOnly | BindingFlags.Instance | 
                BindingFlags.Public);
            for(int i=0;i<memInfo.Length;i++)
            {
                Console.WriteLine(memInfo[i].Name);
            }

            // BindingFlags.IgnoreCase
            Console.WriteLine();
            Console.WriteLine("Using IgnoreCase and invoking the PrintName method.");
            Console.WriteLine("---------------------------------------------------");
            t.InvokeMember("printname", BindingFlags.IgnoreCase | BindingFlags.Static | 
                BindingFlags.Public | BindingFlags.InvokeMethod, null, null, new object[]
                {"Brad","Smith"});

            // BindingFlags.FlattenHierarchy
            Console.WriteLine();
            Console.WriteLine("Using FlattenHierarchy to get inherited static protected and public members." );
            Console.WriteLine("----------------------------------------------------------------------------");
            FieldInfo[] finfos = typeof(MostDerived).GetFields(BindingFlags.NonPublic | BindingFlags.Public |
                  BindingFlags.Static | BindingFlags.FlattenHierarchy);
            foreach (FieldInfo finfo in finfos)
            {
                Console.WriteLine("{0} defined in {1}.", finfo.Name, finfo.DeclaringType.Name);
            }

            Console.WriteLine();
            Console.WriteLine("Without FlattenHierarchy." );
            Console.WriteLine("-------------------------");
            finfos = typeof(MostDerived).GetFields(BindingFlags.NonPublic | BindingFlags.Public |
                  BindingFlags.Static);
            foreach (FieldInfo finfo in finfos)
            {
                Console.WriteLine("{0} defined in {1}.", finfo.Name, finfo.DeclaringType.Name);
            }
        }
    }

    public class TestClass
    {
        public String Name;
        private Object [] values = new Object [] {0, 1,2,3,4,5,6,7,8,9};

        public Object this [int index]
        {
            get
            {
                return values[index];
            }
            set
            {
                values[index] = value;
            }
        }

        public Object Value
        {
            get
            {
                return "the value";
            }
        }

        public TestClass () : this("initialName") {}
        public TestClass (string initName)
        {
            Name = initName;
        }

        int methodCalled = 0;

        public static void SayHello ()
        {
            Console.WriteLine ("Hello");
        }

        public void AddUp ()
        {
            methodCalled++;
            Console.WriteLine ("AddUp Called {0} times", methodCalled);
        }

        public static double ComputeSum (double d1, double d2)
        {
            return d1 + d2;
        }

        public static void PrintName (String firstName, String lastName)
        {
            Console.WriteLine ("{0},{1}", lastName,firstName);
        }

        public void PrintTime ()
        {
            Console.WriteLine (DateTime.Now);
        }

        public void Swap(ref int a, ref int b)
        {
            int x = a;
            a = b;
            b = x;
        }
    }

    [DefaultMemberAttribute ("PrintTime")]
    public class TestClass2
    {
        public void PrintTime ()
        {
            Console.WriteLine (DateTime.Now);
        }
    }

    public class Base
    {
        static int BaseOnlyPrivate = 0;
        protected static int BaseOnly = 0;
    }
    public class Derived : Base
    {
        public static int DerivedOnly = 0;
    }
    public class MostDerived : Derived {}
}

/* This example produces output similar to the following:

Invoking a static method.
-------------------------
Hello

Invoking an instance method.
----------------------------
AddUp Called 1 times
AddUp Called 2 times

Invoking a method with parameters.
---------------------------------
100.09 + 184.45 = 284.54

Invoking a field (getting and setting.)
--------------------------------------
Name == initialName
Name == NewName

Invoking an indexed property (getting and setting.)
--------------------------------------------------
Item[3] == 3
Item[3] == NewValue

Getting a field or property.
----------------------------
Name == NewName
Value == the value

Invoking a method with named parameters.
---------------------------------------
Mouse,Micky

Invoking a default member of a type.
------------------------------------
12/23/2009 4:29:21 PM

Invoking a method with ref parameters.
--------------------------------------
2, 1

Creating an instance with a parameterless constructor.
------------------------------------------------------
Instance of TestClass created.

Creating an instance with a constructor that has parameters.
------------------------------------------------------------
Instance of TestClass created with initial value 'Hello, World!'.

DeclaredOnly instance members.
------------------------------
get_Item
set_Item
get_Value
AddUp
PrintTime
Swap
.ctor
.ctor
Item
Value
Name

Using IgnoreCase and invoking the PrintName method.
---------------------------------------------------
Smith,Brad

Using FlattenHierarchy to get inherited static protected and public members.
----------------------------------------------------------------------------
DerivedOnly defined in Derived.
BaseOnly defined in Base.

Without FlattenHierarchy.
-------------------------

 */
Imports System
Imports System.Reflection
Imports System.IO

Class Invoke

    Public Shared Sub Main()
        ' BindingFlags.InvokeMethod
        ' Call a static method.
        Dim t As Type = GetType(TestClass)

        Console.WriteLine()
        Console.WriteLine("Invoking a static method.")
        Console.WriteLine("-------------------------")
        t.InvokeMember("SayHello", BindingFlags.InvokeMethod Or BindingFlags.Public _
            Or BindingFlags.Static, Nothing, Nothing, New Object() {})

        ' BindingFlags.InvokeMethod
        ' Call an instance method.
        Dim c As New TestClass()
        Console.WriteLine()
        Console.WriteLine("Invoking an instance method.")
        Console.WriteLine("----------------------------")
        c.GetType().InvokeMember("AddUp", BindingFlags.InvokeMethod, Nothing, c, New Object() {})
        c.GetType().InvokeMember("AddUp", BindingFlags.InvokeMethod, Nothing, c, New Object() {})

        ' BindingFlags.InvokeMethod
        ' Call a method with parameters.
        Dim args() As Object = {100.09, 184.45}
        Dim result As Object
        Console.WriteLine()
        Console.WriteLine("Invoking a method with parameters.")
        Console.WriteLine("---------------------------------")
        result = t.InvokeMember("ComputeSum", BindingFlags.InvokeMethod, Nothing, Nothing, args)
        Console.WriteLine("{0} + {1} = {2}", args(0), args(1), result)

        ' BindingFlags.GetField, SetField
        Console.WriteLine()
        Console.WriteLine("Invoking a field (getting and setting.)")
        Console.WriteLine("--------------------------------------")
        ' Get a field value.
        result = t.InvokeMember("Name", BindingFlags.GetField, Nothing, c, New Object() {})
        Console.WriteLine("Name == {0}", result)
        ' Set a field.
        t.InvokeMember("Name", BindingFlags.SetField, Nothing, c, New Object() {"NewName"})
        result = t.InvokeMember("Name", BindingFlags.GetField, Nothing, c, New Object() {})
        Console.WriteLine("Name == {0}", result)

        Console.WriteLine()
        Console.WriteLine("Invoking an indexed property (getting and setting.)")
        Console.WriteLine("--------------------------------------------------")
        ' BindingFlags.GetProperty 
        ' Get an indexed property value.
        Dim index As Integer = 3
        result = t.InvokeMember("Item", BindingFlags.GetProperty, Nothing, c, New Object() {index})
        Console.WriteLine("Item[{0}] == {1}", index, result)
        ' BindingFlags.SetProperty
        ' Set an indexed property value.
        index = 3
        t.InvokeMember("Item", BindingFlags.SetProperty, Nothing, c, New Object() {index, "NewValue"})
        result = t.InvokeMember("Item", BindingFlags.GetProperty, Nothing, c, New Object() {index})
        Console.WriteLine("Item[{0}] == {1}", index, result)

        Console.WriteLine()
        Console.WriteLine("Getting a field or property.")
        Console.WriteLine("----------------------------")
        ' BindingFlags.GetField
        ' Get a field or property.
        result = t.InvokeMember("Name", BindingFlags.GetField Or BindingFlags.GetProperty, Nothing, _
            c, New Object() {})
        Console.WriteLine("Name == {0}", result)
        ' BindingFlags.GetProperty
        result = t.InvokeMember("Value", BindingFlags.GetField Or BindingFlags.GetProperty, Nothing, _
            c, New Object() {})
        Console.WriteLine("Value == {0}", result)

        Console.WriteLine()
        Console.WriteLine("Invoking a method with named parameters.")
        Console.WriteLine("---------------------------------------")
        ' BindingFlags.InvokeMethod
        ' Call a method using named parameters.
        Dim argValues() As Object = {"Mouse", "Micky"}
        Dim argNames() As [String] = {"lastName", "firstName"}
        t.InvokeMember("PrintName", BindingFlags.InvokeMethod, Nothing, Nothing, argValues, Nothing, _
            Nothing, argNames)

        Console.WriteLine()
        Console.WriteLine("Invoking a default member of a type.")
        Console.WriteLine("------------------------------------")
        ' BindingFlags.Default
        ' Call the default member of a type.
        Dim t3 As Type = GetType(TestClass2)
        t3.InvokeMember("", BindingFlags.InvokeMethod Or BindingFlags.Default, Nothing, _
            New TestClass2(), New Object() {})

        Console.WriteLine()
        Console.WriteLine("Invoking a method with ByRef parameters.")
        Console.WriteLine("----------------------------------------")
        ' BindingFlags.Static, NonPublic, and Public
        ' Invoking a member by reference.
        Dim m As MethodInfo = t.GetMethod("Swap")
        args = New Object(1) {}
        args(0) = 1
        args(1) = 2
        m.Invoke(New TestClass(), args)
        Console.WriteLine("{0}, {1}", args(0), args(1))

        ' BindingFlags.CreateInstance
        ' Creating an instance.
        Console.WriteLine()
        Console.WriteLine("Creating an instance with parameterless constructor.")
        Console.WriteLine("----------------------------------------------------")
        Dim obj As Object = GetType(TestClass).InvokeMember("TestClass", BindingFlags.CreateInstance, _
            Nothing, Nothing, New Object() {})
        Console.WriteLine("Instance of {0} created.", obj.GetType().Name)

        Console.WriteLine()
        Console.WriteLine("Creating an instance with a constructor that has parameters.")
        Console.WriteLine("------------------------------------------------------------")
        obj = GetType(TestClass).InvokeMember("TestClass", BindingFlags.CreateInstance, Nothing, _
            Nothing, New Object() { "Hello, World!" })
        Console.WriteLine("Instance of {0} created with initial value '{1}'.", obj.GetType().Name, _
            obj.GetType().InvokeMember("Name", BindingFlags.GetField, Nothing, obj, Nothing))

        ' BindingFlags.DeclaredOnly
        Console.WriteLine()
        Console.WriteLine("DeclaredOnly instance members.")
        Console.WriteLine("------------------------------")
        Dim memInfo As System.Reflection.MemberInfo() = t.GetMembers(BindingFlags.DeclaredOnly Or _
            BindingFlags.Public Or BindingFlags.Instance)
        Dim i As Integer
        For i = 0 To memInfo.Length - 1
            Console.WriteLine(memInfo(i).Name)
        Next i

        ' BindingFlags.IgnoreCase
        Console.WriteLine()
        Console.WriteLine("Using IgnoreCase and invoking the PrintName method.")
        Console.WriteLine("---------------------------------------------------")
        t.InvokeMember("printname", BindingFlags.IgnoreCase Or BindingFlags.Public Or _
            BindingFlags.Static Or BindingFlags.InvokeMethod, Nothing, Nothing, _
            New Object() {"Brad", "Smith"})

        ' BindingFlags.FlattenHierarchy
        Console.WriteLine()
        Console.WriteLine("Using FlattenHierarchy to get inherited static protected and public members." )
        Console.WriteLine("----------------------------------------------------------------------------")
        Dim finfos() As FieldInfo = GetType(MostDerived).GetFields(BindingFlags.NonPublic Or _
              BindingFlags.Public Or BindingFlags.Static Or BindingFlags.FlattenHierarchy)
        For Each finfo As FieldInfo In finfos
            Console.WriteLine("{0} defined in {1}.", finfo.Name, finfo.DeclaringType.Name)
        Next

        Console.WriteLine()
        Console.WriteLine("Without FlattenHierarchy." )
        Console.WriteLine("-------------------------")
        finfos = GetType(MostDerived).GetFields(BindingFlags.NonPublic Or BindingFlags.Public Or _
              BindingFlags.Static)
        For Each finfo As FieldInfo In finfos
            Console.WriteLine("{0} defined in {1}.", finfo.Name, finfo.DeclaringType.Name)
        Next
    End Sub
End Class

Public Class TestClass
    Public Name As String
    Private values() As [Object] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}

    Default Public Property Item(ByVal index As Integer) As [Object]
        Get
            Return values(index)
        End Get
        Set(ByVal Value As [Object])
            values(index) = Value
        End Set
    End Property

    Public ReadOnly Property Value() As [Object]
        Get
            Return "the value"
        End Get
    End Property

    Public Sub New(ByVal initName As String)
        Name = initName
    End Sub 

    Public Sub New()
        MyClass.New("initialName")
    End Sub 

    Private methodCalled As Integer = 0

    Public Shared Sub SayHello()
        Console.WriteLine("Hello")
    End Sub 

    Public Sub AddUp()
        methodCalled += 1
        Console.WriteLine("AddUp Called {0} times", methodCalled)
    End Sub 

    Public Shared Function ComputeSum(ByVal d1 As Double, ByVal d2 As Double) As Double
        Return d1 + d2
    End Function 

    Public Shared Sub PrintName(ByVal firstName As [String], ByVal lastName As [String])
        Console.WriteLine("{0},{1}", lastName, firstName)
    End Sub 

    Public Sub PrintTime()
        Console.WriteLine(DateTime.Now)
    End Sub 

    Public Sub Swap(ByRef a As Integer, ByRef b As Integer)
        Dim x As Integer = a
        a = b
        b = x
    End Sub
End Class

<DefaultMemberAttribute("PrintTime")> _
Public Class TestClass2

    Public Sub PrintTime()
        Console.WriteLine(DateTime.Now)
    End Sub 
End Class

Public Class Base
    Shared BaseOnlyPrivate As Integer = 0
    Protected Shared BaseOnly As Integer = 0
End Class

Public Class Derived 
    Inherits Base
    Public Shared DerivedOnly As Integer = 0
End Class

Public Class MostDerived 
    Inherits Derived
End Class

' This example produces output similar to the following:
'
'Invoking a static method.
'-------------------------
'Hello
'
'Invoking an instance method.
'----------------------------
'AddUp Called 1 times
'AddUp Called 2 times
'
'Invoking a method with parameters.
'---------------------------------
'100.09 + 184.45 = 284.54
'
'Invoking a field (getting and setting.)
'--------------------------------------
'Name == initialName
'Name == NewName
'
'Invoking an indexed property (getting and setting.)
'--------------------------------------------------
'Item[3] == 3
'Item[3] == NewValue
'
'Getting a field or property.
'----------------------------
'Name == NewName
'Value == the value
'
'Invoking a method with named parameters.
'---------------------------------------
'Mouse,Micky
'
'Invoking a default member of a type.
'------------------------------------
'12/23/2009 4:34:22 PM
'
'Invoking a method with ByRef parameters.
'----------------------------------------
'2, 1
'
'Creating an instance with parameterless constructor.
'----------------------------------------------------
'Instance of TestClass created.
'
'Creating an instance with a constructor that has parameters.
'------------------------------------------------------------
'Instance of TestClass created with initial value 'Hello, World!'.
'
'DeclaredOnly instance members.
'------------------------------
'get_Item
'set_Item
'get_Value
'AddUp
'PrintTime
'Swap
'.ctor
'.ctor
'Item
'Value
'Name
'
'Using IgnoreCase and invoking the PrintName method.
'---------------------------------------------------
'Smith,Brad
'
'Using FlattenHierarchy to get inherited static protected and public members.
'----------------------------------------------------------------------------
'DerivedOnly defined in Derived.
'BaseOnly defined in Base.
'
'Without FlattenHierarchy.
'-------------------------
'

Remarks

These BindingFlags control binding for a great many classes in the System, System.Reflection, and System.Runtime namespaces that invoke, create, get, set, and find members and types.

BindingFlags are used in the following Type methods and other places such as MethodBase.Invoke :

InvokeMember and GetMethod are especially important.

The binding flags can be categorized by how they identify a type member, as listed in the following table.

Identified by Accessibility Identified by Binding Argument Identified by Operation
DeclaredOnly

FlattenHierarchy

IgnoreCase

IgnoreReturn

Instance

NonPublic

Public

Static
ExactBinding

OptionalParamBinding
CreateInstance

GetField

SetField

GetProperty

SetProperty

InvokeMethod

PutDispProperty

PutRefDispProperty

Note

You must specify Instance or Static along with Public or NonPublic or no members will be returned.

The following table lists the coercions performed by the default Binder.ChangeType. This table applies especially to the ExactBinding binding flag.

Source Type Target Type
Any type Its base type.
Any type The interface it implements.
Char UInt16, UInt32, Int32, UInt64, Int64, Single, Double
Byte Char, UInt16, Int16, UInt32, Int32, UInt64, Int64, Single, Double
SByte Int16, Int32, Int64, Single, Double
UInt16 UInt32, Int32, UInt64, Int64, Single, Double
Int16 Int32, Int64, Single, Double
UInt32 UInt64, Int64, Single, Double
Int32 Int64, Single, Double
UInt64 Single, Double
Int64 Single, Double
Single Double
Non-reference By-reference.

Applies to