PropertyBuilder 类
定义类型的属性 (Property)。
**命名空间:**System.Reflection.Emit
**程序集:**mscorlib（在 mscorlib.dll 中）
语法
声明
<ClassInterfaceAttribute(ClassInterfaceType.None)> _
<ComVisibleAttribute(True)> _
Public NotInheritable Class PropertyBuilder
Inherits PropertyInfo
Implements _PropertyBuilder
用法
Dim instance As PropertyBuilder
[ClassInterfaceAttribute(ClassInterfaceType.None)]
[ComVisibleAttribute(true)]
public sealed class PropertyBuilder : PropertyInfo, _PropertyBuilder
[ClassInterfaceAttribute(ClassInterfaceType::None)]
[ComVisibleAttribute(true)]
public ref class PropertyBuilder sealed : public PropertyInfo, _PropertyBuilder
/** @attribute ClassInterfaceAttribute(ClassInterfaceType.None) */
/** @attribute ComVisibleAttribute(true) */
public final class PropertyBuilder extends PropertyInfo implements _PropertyBuilder
ClassInterfaceAttribute(ClassInterfaceType.None)
ComVisibleAttribute(true)
public final class PropertyBuilder extends PropertyInfo implements _PropertyBuilder
备注
提示
应用于此类的 HostProtectionAttribute 属性 (Attribute) 的 Resources 属性 (Property) 值如下：MayLeakOnAbort。HostProtectionAttribute 不影响桌面应用程序（桌面应用程序一般通过双击图标，键入命令或在浏览器中输入 URL 启动）。有关更多信息，请参见 HostProtectionAttribute 类或 SQL Server 编程和宿主保护属性。
PropertyBuilder 总是与 TypeBuilder 关联。TypeBuilder . DefineProperty 方法向客户端返回新的 PropertyBuilder。
示例
下面的代码示例演示如何使用通过 TypeBuilder.DefineProperty 获得的 PropertyBuilder 实现动态类型中的属性 (Property)，以创建属性 (Property) 框架及关联的 MethodBuilder，在属性中实现 IL 逻辑。
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 [System.String]' 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 [System.String]' created!
// ---
// The customerName field of instance custData has been set to 'Joe User'.
// -------------------
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 [System.String]' created!
// ---
// The customerName field of instance custData has been set to 'Joe User'.
// -------------------
继承层次结构
System.Object
System.Reflection.MemberInfo
System.Reflection.PropertyInfo
System.Reflection.Emit.PropertyBuilder
线程安全
此类型的任何公共静态（Visual Basic 中的 Shared）成员都是线程安全的，但不保证所有实例成员都是线程安全的。
平台
Windows 98、Windows 2000 SP4、Windows Millennium Edition、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition
.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。
版本信息
.NET Framework
受以下版本支持：2.0、1.1、1.0