BindingFlags Enumerazione
Definizione
Importante
Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.
Specifica i flag che controllano l'associazione e la modalità in cui la ricerca di membri e tipi viene effettuata mediante reflection.
Questa enumerazione supporta una combinazione bit per bit dei rispettivi valori dei membri.
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- Ereditarietà
- Attributi
Campi
| CreateInstance | 512 | Specifica che la funzionalità di reflection deve creare un'istanza del tipo specificato. Chiama il costruttore corrispondente agli argomenti specificati. Il nome del membro fornito viene ignorato. Se non viene specificato il tipo della ricerca, verrà applicato (Instance | Public). Non è possibile chiamare un inizializzatore dei tipi. Questo flag viene passato a un metodo |
| DeclaredOnly | 2 | Specifica che solo i membri dichiarati a livello della gerarchia del tipo fornito devono essere considerati. I membri ereditati non vengono considerati. |
| Default | 0 | Specifica che non sono definiti flag di associazione. |
| DoNotWrapExceptions | 33554432 | |
| ExactBinding | 65536 | Specifica che i tipi degli argomenti specificati devono corrispondere esattamente ai tipi dei parametri formali corrispondenti. La funzionalità di reflection genera un'eccezione se il chiamante fornisce un oggetto |
| FlattenHierarchy | 64 | Specifica che devono essere restituiti i membri statici protetti e pubblici nella gerarchia. I membri statici privati presenti nelle classi ereditate non vengono restituiti. I membri statici comprendono campi, metodi, eventi e proprietà. I tipi annidati non vengono restituiti. |
| GetField | 1024 | Specifica che deve essere restituito il valore del campo specificato. Questo flag viene passato a un metodo |
| GetProperty | 4096 | Specifica che deve essere restituito il valore della proprietà specificata. Questo flag viene passato a un metodo |
| IgnoreCase | 1 | Specifica che la combinazione di maiuscole e minuscole del nome del membro non deve essere considerata durante l'associazione. |
| IgnoreReturn | 16777216 | Usato nell'interoperabilità COM per specificare che il valore restituito del membro può essere ignorato. |
| Instance | 4 | Specifica che i membri dell'istanza devono essere inclusi nella ricerca. |
| InvokeMethod | 256 | Specifica che un metodo deve essere richiamato. Non deve trattarsi di un costruttore o un inizializzatore di tipi. Questo flag viene passato a un metodo |
| NonPublic | 32 | Specifica che i membri non pubblici devono essere inclusi nella ricerca. |
| OptionalParamBinding | 262144 | Restituisce il set di membri il cui numero di parametri corrisponde al numero di argomenti forniti. Questo flag di associazione viene usato per i metodi con parametri che hanno valori predefiniti e per i metodi con argomenti variabili (varargs). Questo flag deve essere usato solo con InvokeMember(String, BindingFlags, Binder, Object, Object[], ParameterModifier[], CultureInfo, String[]). |
| Public | 16 | Specifica che i membri pubblici devono essere inclusi nella ricerca. |
| PutDispProperty | 16384 | Specifica che deve essere richiamato il membro |
| PutRefDispProperty | 32768 | Specifica che deve essere richiamato il membro |
| SetField | 2048 | Specifica che il valore del campo specificato deve essere impostato. Questo flag viene passato a un metodo |
| SetProperty | 8192 | Specifica che il valore della proprietà specificata deve essere impostato. Per le proprietà COM, specificare questo flag di associazione equivale a specificare Questo flag viene passato a un metodo |
| Static | 8 | Specifica che i membri statici devono essere inclusi nella ricerca. |
| SuppressChangeType | 131072 | Non implementato. |
Esempio
Nell'esempio seguente vengono illustrati molti flag di associazione.
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.
'-------------------------
'
Commenti
Queste BindingFlags associazioni di controllo per molte classi negli Systemspazi dei nomi , System.Reflectione System.Runtime che richiamano, creano, ottengono, impostano e trovano membri e tipi.
BindingFlags vengono usati nei metodi seguenti Type e in altre posizioni, ad MethodBase.Invokeesempio :
InvokeMember e GetMethod sono particolarmente importanti.
I flag di associazione possono essere classificati in base al modo in cui identificano un membro del tipo, come indicato nella tabella seguente.
| Identificato dall'accessibilità | Identificato dall'argomento di associazione | Identificato dall'operazione |
|---|---|---|
| DichiaratoOnly FlattenHierarchy IgnoreCase IgnoreReturn Istanza Nonpublic Pubblico Static |
ExactBinding OptionalParamBinding |
CreateInstance GetField Setfield Getproperty SetProperty InvokeMethod PutDispProperty PutRefDispProperty |
Nota
È necessario specificare Instance o Static insieme Public o NonPublic nessun membro verrà restituito.
Nella tabella seguente sono elencate le coercioni eseguite dal valore predefinito Binder.ChangeType. Questa tabella si applica soprattutto al flag di BindingFlags.ExactBinding associazione. Il principio generale è che ChangeType deve eseguire solo coercioni ampliati, che non perderanno mai dati. Un esempio di coercizione di estensione consiste nel coercing di un valore con segno a 32 bit su un valore intero con segno a 64 bit. Questo è distinto da una coercizione ristretta, che può perdere dati. Un esempio di coercizione ristretta prevede la coercing di un intero con segno a 64 bit in un intero con segno a 32 bit.
| Tipo di origine | Tipo destinazione |
|---|---|
| Qualsiasi tipo | Tipo di base. |
| Qualsiasi tipo | Interfaccia implementata. |
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 riferimento | Riferimento per riferimento. |
Quando viene usato il BindingFlags.ExactBinding flag di associazione, la reflection modella le regole di accessibilità del sistema di tipi comuni. Ad esempio, se il chiamante si trova nello stesso assembly, il chiamante non richiede autorizzazioni speciali per i membri interni. In caso contrario, il chiamante necessita ReflectionPermissiondi . Ciò è coerente con la ricerca di membri protetti, privati e così via.
Si applica a
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