BindingFlags Enumeração
Definição
Importante
Algumas informações se referem a produtos de pré-lançamento que podem ser substancialmente modificados antes do lançamento. A Microsoft não oferece garantias, expressas ou implícitas, das informações aqui fornecidas.
Especifica sinalizadores que controlam a ligação e a maneira na qual a pesquisa por tipos e membros é realizada por reflexão.
Essa enumeração dá suporte a uma combinação bit a bit dos valores de membro.
public enum class BindingFlags[System.Flags]
public enum BindingFlags[System.Flags]
[System.Serializable]
public enum BindingFlags[System.Flags]
[System.Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public enum BindingFlags[<System.Flags>]
type BindingFlags = [<System.Flags>]
[<System.Serializable>]
type BindingFlags = [<System.Flags>]
[<System.Serializable>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type BindingFlags = Public Enum BindingFlags- Herança
- Atributos
Campos
| CreateInstance | 512 | Especifica que a reflexão deve criar uma instância do tipo especificado. Chama o construtor que corresponde aos argumentos fornecidos. O nome de membro fornecido é ignorado. Se o tipo de pesquisa não for especificado, (Instance | Public) será aplicado. Não é possível chamar um inicializador de tipo. Este sinalizador é passado para um método |
| DeclaredOnly | 2 | Especifica que somente os membros declarados no nível da hierarquia do tipo fornecido devem ser considerados. Membros herdados não são considerados. |
| Default | 0 | Especifica que nenhum sinalizador de associação é definido. |
| DoNotWrapExceptions | 33554432 | |
| ExactBinding | 65536 | Especifica que os tipos dos argumentos fornecidos devem corresponder exatamente aos tipos dos parâmetros formais correspondentes. A reflexão gerará uma exceção se o chamador fornecer um objeto |
| FlattenHierarchy | 64 | Especifica que os membros estáticos públicos e protegidos da hierarquia devem ser retornados. Membros estáticos privados em classes herdadas não são retornados. Membros estáticos incluem campos, métodos, eventos e propriedades. Tipos aninhados não são retornados. |
| GetField | 1024 | Especifica que o valor do campo especificado deve ser retornado. Este sinalizador é passado para um método |
| GetProperty | 4096 | Especifica que o valor da propriedade especificada deve ser retornado. Este sinalizador é passado para um método |
| IgnoreCase | 1 | Especifica que as maiúsculas e minúsculas do nome do membro não devem ser consideradas durante a associação. |
| IgnoreReturn | 16777216 | Usado na interoperabilidade COM para especificar que o valor retornado do membro pode ser ignorado. |
| Instance | 4 | Especifica que os membros da instância devem ser incluídos na pesquisa. |
| InvokeMethod | 256 | Especifica que um método deve ser invocado. Isso não deve ser um construtor nem um inicializador de tipo. Este sinalizador é passado para um método |
| NonPublic | 32 | Especifica que os membros não públicos devem ser incluídos na pesquisa. |
| OptionalParamBinding | 262144 | Retorna o conjunto de membros cuja contagem de parâmetros corresponde ao número de argumentos fornecidos. Este sinalizador de associação é usado para métodos com parâmetros que têm valores padrão e métodos com argumentos variáveis (varargs). Este sinalizador deve ser usado somente com InvokeMember(String, BindingFlags, Binder, Object, Object[], ParameterModifier[], CultureInfo, String[]). |
| Public | 16 | Especifica que os membros públicos devem ser incluídos na pesquisa. |
| PutDispProperty | 16384 | Especifica que o membro |
| PutRefDispProperty | 32768 | Especifica que o membro |
| SetField | 2048 | Especifica que o valor do campo especificado deve ser definido. Este sinalizador é passado para um método |
| SetProperty | 8192 | Especifica que o valor da propriedade especificada deve ser definido. Para propriedades COM, especificar esse sinalizador de associação é equivalente a especificar Este sinalizador é passado para um método |
| Static | 8 | Especifica que os membros estáticos devem ser incluídos na pesquisa. |
| SuppressChangeType | 131072 | Não implementado. |
Exemplos
O exemplo a seguir demonstra muitos dos sinalizadores de associação.
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.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.
'-------------------------
'
Comentários
Essas BindingFlags associações de controle para muitas classes no System, System.Reflectione System.Runtime namespaces que invocam, criam, obtêm, definem e encontram membros e tipos.
BindingFlags são usados nos seguintes Type métodos e em outros locais, como MethodBase.Invoke:
InvokeMember e GetMethod são especialmente importantes.
Os sinalizadores de associação podem ser categorizados pela forma como identificam um membro do tipo, conforme listado na tabela a seguir.
| Identificado por Acessibilidade | Identificado por argumento de associação | Identificado por operação |
|---|---|---|
| Declaredonlypara Flattenhierarchy IgnoreCase IgnoreReturn Instância Confidenciais Público Estático |
ExactBinding OptionalParamBinding |
CreateInstance GetField Setfield Getproperty SetProperty InvokeMethod PutDispProperty PutRefDispProperty |
Observação
Você deve especificar Instance ou Static junto com Public ou NonPublic nenhum membro será retornado.
A tabela a seguir lista as coerções executadas por padrão Binder.ChangeType. Essa tabela se aplica especialmente ao sinalizador de BindingFlags.ExactBinding associação. O princípio geral é que ChangeType deve executar apenas coerções de ampliação, que nunca perdem dados. Um exemplo de uma coerção de expansão é coagir um valor que é um inteiro com sinal de 32 bits para um valor que é um inteiro com sinal de 64 bits. Isso é diferenciado de uma coerção de restrição, que pode perder dados. Um exemplo de coerção de restrição é coagir um inteiro com sinal de 64 bits para um inteiro com sinal de 32 bits.
| Tipo de Fonte | Tipo de destino |
|---|---|
| Qualquer tipo | Seu tipo base. |
| Qualquer tipo | A interface que ela implementa. |
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 |
| Não referência | Por referência. |
Quando o BindingFlags.ExactBinding sinalizador de associação é usado, a reflexão modela as regras de acessibilidade do sistema de tipo comum. Por exemplo, se o chamador estiver no mesmo assembly, o chamador não precisará de permissões especiais para membros internos. Caso contrário, o chamador precisará ReflectionPermission. Isso é consistente com a pesquisa de membros protegidos, privados e assim por diante.