PropertyBuilder
PropertyBuilder
PropertyBuilder
PropertyBuilder
Class
Definition
Defines the properties for a type.
public ref class PropertyBuilder sealed : System::Reflection::PropertyInfo, System::Runtime::InteropServices::_PropertyBuilder
[System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.None)]
[System.Runtime.InteropServices.ComVisible(true)]
public sealed class PropertyBuilder : System.Reflection.PropertyInfo, System.Runtime.InteropServices._PropertyBuilder
type PropertyBuilder = class
inherit PropertyInfo
interface _PropertyBuilder
Public NotInheritable Class PropertyBuilder
Inherits PropertyInfo
Implements _PropertyBuilder
- Inheritance
-
PropertyBuilderPropertyBuilderPropertyBuilderPropertyBuilder
- Attributes
- Implements
Examples
The following code sample demonstrates how to implement properties in a dynamic type using a PropertyBuilder
obtained via TypeBuilder.DefineProperty to create the property framework and an associated MethodBuilder to implement the IL logic within the property.
using namespace System;
using namespace System::Threading;
using namespace System::Reflection;
using namespace System::Reflection::Emit;
Type^ BuildDynamicTypeWithProperties()
{
AppDomain^ myDomain = Thread::GetDomain();
AssemblyName^ myAsmName = gcnew AssemblyName;
myAsmName->Name = "MyDynamicAssembly";
// To generate a persistable assembly, specify AssemblyBuilderAccess::RunAndSave.
AssemblyBuilder^ myAsmBuilder =
myDomain->DefineDynamicAssembly( myAsmName, AssemblyBuilderAccess::RunAndSave );
// Generate a persistable single-module assembly.
ModuleBuilder^ myModBuilder =
myAsmBuilder->DefineDynamicModule( myAsmName->Name, myAsmName->Name + ".dll" );
TypeBuilder^ myTypeBuilder = myModBuilder->DefineType( "CustomerData", TypeAttributes::Public );
// Define a private field to hold the property value.
FieldBuilder^ customerNameBldr = myTypeBuilder->DefineField( "customerName", String::typeid, FieldAttributes::Private );
// The last argument of DefineProperty is an empty array of Type
// objects, because the property has no parameters. (Alternatively,
// you can specify a null value.)
PropertyBuilder^ custNamePropBldr =
myTypeBuilder->DefineProperty( "CustomerName", PropertyAttributes::HasDefault, String::typeid, gcnew array<Type^>(0) );
// The property set and property get methods require a special
// set of attributes.
MethodAttributes getSetAttr =
MethodAttributes::Public | MethodAttributes::SpecialName |
MethodAttributes::HideBySig;
// Define the "get" accessor method for CustomerName.
MethodBuilder^ custNameGetPropMthdBldr =
myTypeBuilder->DefineMethod( "get_CustomerName",
getSetAttr,
String::typeid,
Type::EmptyTypes );
ILGenerator^ custNameGetIL = custNameGetPropMthdBldr->GetILGenerator();
custNameGetIL->Emit( OpCodes::Ldarg_0 );
custNameGetIL->Emit( OpCodes::Ldfld, customerNameBldr );
custNameGetIL->Emit( OpCodes::Ret );
// Define the "set" accessor method for CustomerName.
array<Type^>^temp2 = {String::typeid};
MethodBuilder^ custNameSetPropMthdBldr =
myTypeBuilder->DefineMethod( "set_CustomerName",
getSetAttr,
nullptr,
temp2 );
ILGenerator^ custNameSetIL = custNameSetPropMthdBldr->GetILGenerator();
custNameSetIL->Emit( OpCodes::Ldarg_0 );
custNameSetIL->Emit( OpCodes::Ldarg_1 );
custNameSetIL->Emit( OpCodes::Stfld, customerNameBldr );
custNameSetIL->Emit( OpCodes::Ret );
// Last, we must map the two methods created above to our PropertyBuilder to
// their corresponding behaviors, "get" and "set" respectively.
custNamePropBldr->SetGetMethod( custNameGetPropMthdBldr );
custNamePropBldr->SetSetMethod( custNameSetPropMthdBldr );
Type^ retval = myTypeBuilder->CreateType();
// Save the assembly so it can be examined with Ildasm.exe,
// or referenced by a test program.
myAsmBuilder->Save(myAsmName->Name + ".dll");
return retval;
}
int main()
{
Type^ custDataType = BuildDynamicTypeWithProperties();
array<PropertyInfo^>^custDataPropInfo = custDataType->GetProperties();
System::Collections::IEnumerator^ myEnum = custDataPropInfo->GetEnumerator();
while ( myEnum->MoveNext() )
{
PropertyInfo^ pInfo = safe_cast<PropertyInfo^>(myEnum->Current);
Console::WriteLine( "Property '{0}' created!", pInfo );
}
Console::WriteLine( "---" );
// Note that when invoking a property, you need to use the proper BindingFlags -
// BindingFlags::SetProperty when you invoke the "set" behavior, and
// BindingFlags::GetProperty when you invoke the "get" behavior. Also note that
// we invoke them based on the name we gave the property, as expected, and not
// the name of the methods we bound to the specific property behaviors.
Object^ custData = Activator::CreateInstance( custDataType );
array<Object^>^temp3 = {"Joe User"};
custDataType->InvokeMember( "CustomerName", BindingFlags::SetProperty, nullptr, custData, temp3 );
Console::WriteLine( "The customerName field of instance custData has been set to '{0}'.", custDataType->InvokeMember( "CustomerName", BindingFlags::GetProperty, nullptr, custData, gcnew array<Object^>(0) ) );
}
// --- O U T P U T ---
// The output should be as follows:
// -------------------
// Property 'System.String CustomerName' created!
// ---
// The customerName field of instance custData has been set to 'Joe User'.
// -------------------
using System;
using System.Threading;
using System.Reflection;
using System.Reflection.Emit;
class PropertyBuilderDemo
{
public static Type BuildDynamicTypeWithProperties()
{
AppDomain myDomain = Thread.GetDomain();
AssemblyName myAsmName = new AssemblyName();
myAsmName.Name = "MyDynamicAssembly";
// To generate a persistable assembly, specify AssemblyBuilderAccess.RunAndSave.
AssemblyBuilder myAsmBuilder = myDomain.DefineDynamicAssembly(myAsmName,
AssemblyBuilderAccess.RunAndSave);
// Generate a persistable single-module assembly.
ModuleBuilder myModBuilder =
myAsmBuilder.DefineDynamicModule(myAsmName.Name, myAsmName.Name + ".dll");
TypeBuilder myTypeBuilder = myModBuilder.DefineType("CustomerData",
TypeAttributes.Public);
FieldBuilder customerNameBldr = myTypeBuilder.DefineField("customerName",
typeof(string),
FieldAttributes.Private);
// The last argument of DefineProperty is null, because the
// property has no parameters. (If you don't specify null, you must
// specify an array of Type objects. For a parameterless property,
// use an array with no elements: new Type[] {})
PropertyBuilder custNamePropBldr = myTypeBuilder.DefineProperty("CustomerName",
PropertyAttributes.HasDefault,
typeof(string),
null);
// The property set and property get methods require a special
// set of attributes.
MethodAttributes getSetAttr =
MethodAttributes.Public | MethodAttributes.SpecialName |
MethodAttributes.HideBySig;
// Define the "get" accessor method for CustomerName.
MethodBuilder custNameGetPropMthdBldr =
myTypeBuilder.DefineMethod("get_CustomerName",
getSetAttr,
typeof(string),
Type.EmptyTypes);
ILGenerator custNameGetIL = custNameGetPropMthdBldr.GetILGenerator();
custNameGetIL.Emit(OpCodes.Ldarg_0);
custNameGetIL.Emit(OpCodes.Ldfld, customerNameBldr);
custNameGetIL.Emit(OpCodes.Ret);
// Define the "set" accessor method for CustomerName.
MethodBuilder custNameSetPropMthdBldr =
myTypeBuilder.DefineMethod("set_CustomerName",
getSetAttr,
null,
new Type[] { typeof(string) });
ILGenerator custNameSetIL = custNameSetPropMthdBldr.GetILGenerator();
custNameSetIL.Emit(OpCodes.Ldarg_0);
custNameSetIL.Emit(OpCodes.Ldarg_1);
custNameSetIL.Emit(OpCodes.Stfld, customerNameBldr);
custNameSetIL.Emit(OpCodes.Ret);
// Last, we must map the two methods created above to our PropertyBuilder to
// their corresponding behaviors, "get" and "set" respectively.
custNamePropBldr.SetGetMethod(custNameGetPropMthdBldr);
custNamePropBldr.SetSetMethod(custNameSetPropMthdBldr);
Type retval = myTypeBuilder.CreateType();
// Save the assembly so it can be examined with Ildasm.exe,
// or referenced by a test program.
myAsmBuilder.Save(myAsmName.Name + ".dll");
return retval;
}
public static void Main()
{
Type custDataType = BuildDynamicTypeWithProperties();
PropertyInfo[] custDataPropInfo = custDataType.GetProperties();
foreach (PropertyInfo pInfo in custDataPropInfo) {
Console.WriteLine("Property '{0}' created!", pInfo.ToString());
}
Console.WriteLine("---");
// Note that when invoking a property, you need to use the proper BindingFlags -
// BindingFlags.SetProperty when you invoke the "set" behavior, and
// BindingFlags.GetProperty when you invoke the "get" behavior. Also note that
// we invoke them based on the name we gave the property, as expected, and not
// the name of the methods we bound to the specific property behaviors.
object custData = Activator.CreateInstance(custDataType);
custDataType.InvokeMember("CustomerName", BindingFlags.SetProperty,
null, custData, new object[]{ "Joe User" });
Console.WriteLine("The customerName field of instance custData has been set to '{0}'.",
custDataType.InvokeMember("CustomerName", BindingFlags.GetProperty,
null, custData, new object[]{ }));
}
}
// --- O U T P U T ---
// The output should be as follows:
// -------------------
// Property 'System.String CustomerName' created!
// ---
// The customerName field of instance custData has been set to 'Joe User'.
// -------------------
Imports System
Imports System.Threading
Imports System.Reflection
Imports System.Reflection.Emit
Class PropertyBuilderDemo
Public Shared Function BuildDynamicTypeWithProperties() As Type
Dim myDomain As AppDomain = Thread.GetDomain()
Dim myAsmName As New AssemblyName()
myAsmName.Name = "MyDynamicAssembly"
' To generate a persistable assembly, specify AssemblyBuilderAccess.RunAndSave.
Dim myAsmBuilder As AssemblyBuilder = myDomain.DefineDynamicAssembly(myAsmName, _
AssemblyBuilderAccess.RunAndSave)
' Generate a persistable, single-module assembly.
Dim myModBuilder As ModuleBuilder = _
myAsmBuilder.DefineDynamicModule(myAsmName.Name, myAsmName.Name & ".dll")
Dim myTypeBuilder As TypeBuilder = myModBuilder.DefineType("CustomerData", TypeAttributes.Public)
' Define a private field to hold the property value.
Dim customerNameBldr As FieldBuilder = myTypeBuilder.DefineField("customerName", _
GetType(String), FieldAttributes.Private)
' The last argument of DefineProperty is Nothing, because the
' property has no parameters. (If you don't specify Nothing, you must
' specify an array of Type objects. For a parameterless property,
' use an array with no elements: New Type() {})
Dim custNamePropBldr As PropertyBuilder = _
myTypeBuilder.DefineProperty("CustomerName", _
PropertyAttributes.HasDefault, _
GetType(String), _
Nothing)
' The property set and property get methods require a special
' set of attributes.
Dim getSetAttr As MethodAttributes = _
MethodAttributes.Public Or MethodAttributes.SpecialName _
Or MethodAttributes.HideBySig
' Define the "get" accessor method for CustomerName.
Dim custNameGetPropMthdBldr As MethodBuilder = _
myTypeBuilder.DefineMethod("GetCustomerName", _
getSetAttr, _
GetType(String), _
Type.EmptyTypes)
Dim custNameGetIL As ILGenerator = custNameGetPropMthdBldr.GetILGenerator()
custNameGetIL.Emit(OpCodes.Ldarg_0)
custNameGetIL.Emit(OpCodes.Ldfld, customerNameBldr)
custNameGetIL.Emit(OpCodes.Ret)
' Define the "set" accessor method for CustomerName.
Dim custNameSetPropMthdBldr As MethodBuilder = _
myTypeBuilder.DefineMethod("get_CustomerName", _
getSetAttr, _
Nothing, _
New Type() {GetType(String)})
Dim custNameSetIL As ILGenerator = custNameSetPropMthdBldr.GetILGenerator()
custNameSetIL.Emit(OpCodes.Ldarg_0)
custNameSetIL.Emit(OpCodes.Ldarg_1)
custNameSetIL.Emit(OpCodes.Stfld, customerNameBldr)
custNameSetIL.Emit(OpCodes.Ret)
' Last, we must map the two methods created above to our PropertyBuilder to
' their corresponding behaviors, "get" and "set" respectively.
custNamePropBldr.SetGetMethod(custNameGetPropMthdBldr)
custNamePropBldr.SetSetMethod(custNameSetPropMthdBldr)
Dim retval As Type = myTypeBuilder.CreateType()
' Save the assembly so it can be examined with Ildasm.exe,
' or referenced by a test program.
myAsmBuilder.Save(myAsmName.Name & ".dll")
return retval
End Function 'BuildDynamicTypeWithProperties
Public Shared Sub Main()
Dim custDataType As Type = BuildDynamicTypeWithProperties()
Dim custDataPropInfo As PropertyInfo() = custDataType.GetProperties()
Dim pInfo As PropertyInfo
For Each pInfo In custDataPropInfo
Console.WriteLine("Property '{0}' created!", pInfo.ToString())
Next pInfo
Console.WriteLine("---")
' Note that when invoking a property, you need to use the proper BindingFlags -
' BindingFlags.SetProperty when you invoke the "set" behavior, and
' BindingFlags.GetProperty when you invoke the "get" behavior. Also note that
' we invoke them based on the name we gave the property, as expected, and not
' the name of the methods we bound to the specific property behaviors.
Dim custData As Object = Activator.CreateInstance(custDataType)
custDataType.InvokeMember("CustomerName", BindingFlags.SetProperty, Nothing, _
custData, New Object() {"Joe User"})
Console.WriteLine("The customerName field of instance custData has been set to '{0}'.", _
custDataType.InvokeMember("CustomerName", BindingFlags.GetProperty, _
Nothing, custData, New Object() {}))
End Sub 'Main
End Class 'PropertyBuilderDemo
' --- O U T P U T ---
' The output should be as follows:
' -------------------
' Property 'System.String CustomerName' created!
' ---
' The customerName field of instance custData has been set to 'Joe User'.
' -------------------
Remarks
A PropertyBuilder
is always associated with a TypeBuilder
. The TypeBuilder
. DefineProperty
method will return a new PropertyBuilder
to a client.
Properties
Attributes Attributes Attributes Attributes |
Gets the attributes for this property. |
CanRead CanRead CanRead CanRead |
Gets a value indicating whether the property can be read. |
CanWrite CanWrite CanWrite CanWrite |
Gets a value indicating whether the property can be written to. |
CustomAttributes CustomAttributes CustomAttributes CustomAttributes |
Gets a collection that contains this member's custom attributes. (Inherited from MemberInfo) |
DeclaringType DeclaringType DeclaringType DeclaringType |
Gets the class that declares this member. |
GetMethod GetMethod GetMethod GetMethod |
Gets the |
IsSpecialName IsSpecialName IsSpecialName IsSpecialName |
Gets a value indicating whether the property is the special name. (Inherited from PropertyInfo) |
MemberType MemberType MemberType MemberType |
Gets a MemberTypes value indicating that this member is a property. (Inherited from PropertyInfo) |
MetadataToken MetadataToken MetadataToken MetadataToken |
Gets a value that identifies a metadata element. (Inherited from MemberInfo) |
Module Module Module Module |
Gets the module in which the type that declares the current property is being defined. |
Name Name Name Name |
Gets the name of this member. |
PropertyToken PropertyToken PropertyToken PropertyToken |
Retrieves the token for this property. |
PropertyType PropertyType PropertyType PropertyType |
Gets the type of the field of this property. |
ReflectedType ReflectedType ReflectedType ReflectedType |
Gets the class object that was used to obtain this instance of |
SetMethod SetMethod SetMethod SetMethod |
Gets the |
Methods
Explicit Interface Implementations
Extension Methods
Applies to
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