ParameterBuilder Class

Definition

Creates or associates parameter information.

public ref class ParameterBuilder : System::Runtime::InteropServices::_ParameterBuilder
[System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.None)]
[System.Runtime.InteropServices.ComVisible(true)]
public class ParameterBuilder : System.Runtime.InteropServices._ParameterBuilder
type ParameterBuilder = class
    interface _ParameterBuilder
Public Class ParameterBuilder
Implements _ParameterBuilder
Inheritance
ParameterBuilder
Attributes
Implements

Examples

The following example demonstrates how to create a dynamic method with a parameter passed by reference using ParameterBuilder.

using namespace System;
using namespace System::Threading;
using namespace System::Reflection;
using namespace System::Reflection::Emit;
Type^ BuildCustomerDataType()
{
   AppDomain^ myDomain = Thread::GetDomain();
   AssemblyName^ myAsmName = gcnew AssemblyName;
   myAsmName->Name = "MyDynamicAssembly";
   AssemblyBuilder^ myAsmBuilder = myDomain->DefineDynamicAssembly( myAsmName, AssemblyBuilderAccess::Run );
   ModuleBuilder^ myModBuilder = myAsmBuilder->DefineDynamicModule( "MyMod" );
   TypeBuilder^ myTypeBuilder = myModBuilder->DefineType( "CustomerData", TypeAttributes::Public );
   FieldBuilder^ customerNameBldr = myTypeBuilder->DefineField( "customerName", String::typeid, FieldAttributes::Private );
   FieldBuilder^ acctIDBldr = myTypeBuilder->DefineField( "acctID", String::typeid, FieldAttributes::Private );
   FieldBuilder^ balanceAmtBldr = myTypeBuilder->DefineField( "balanceAmt", double::typeid, FieldAttributes::Private );
   array<Type^>^temp0 = {String::typeid,String::typeid,double::typeid};
   ConstructorBuilder^ myCtorBuilder = myTypeBuilder->DefineConstructor( MethodAttributes::Public, CallingConventions::HasThis, temp0 );
   ILGenerator^ ctorIL = myCtorBuilder->GetILGenerator();
   Type^ objType = Type::GetType( "System.Object" );
   ConstructorInfo^ objCtor = objType->GetConstructor( gcnew array<Type^>(0) );
   ctorIL->Emit( OpCodes::Ldarg_0 );
   ctorIL->Emit( OpCodes::Call, objCtor );
   ctorIL->Emit( OpCodes::Ldarg_0 );
   ctorIL->Emit( OpCodes::Ldarg_1 );
   ctorIL->Emit( OpCodes::Stfld, customerNameBldr );
   ctorIL->Emit( OpCodes::Ldarg_0 );
   ctorIL->Emit( OpCodes::Ldarg_2 );
   ctorIL->Emit( OpCodes::Stfld, acctIDBldr );
   ctorIL->Emit( OpCodes::Ldarg_0 );
   ctorIL->Emit( OpCodes::Ldarg_3 );
   ctorIL->Emit( OpCodes::Stfld, balanceAmtBldr );
   ctorIL->Emit( OpCodes::Ret );
   
   // This method will take an amount from a static pool and add it to the balance.
   // Note that we are passing the first parameter, fundsPool, by reference. Therefore,
   // we need to inform the MethodBuilder to expect a ref, by declaring the first
   // parameter's type to be System::Double& (a reference to a double).
   array<Type^>^temp4 = {Type::GetType( "System.Double&" ),double::typeid};
   MethodBuilder^ myMthdBuilder = myTypeBuilder->DefineMethod( "AddFundsFromPool", MethodAttributes::Public, double::typeid, temp4 );
   ParameterBuilder^ poolRefBuilder = myMthdBuilder->DefineParameter( 1, ParameterAttributes::Out, "fundsPool" );
   ParameterBuilder^ amountFromPoolBuilder = myMthdBuilder->DefineParameter( 2, ParameterAttributes::In, "amountFromPool" );
   ILGenerator^ mthdIL = myMthdBuilder->GetILGenerator();
   mthdIL->Emit( OpCodes::Ldarg_1 );
   mthdIL->Emit( OpCodes::Ldarg_1 );
   mthdIL->Emit( OpCodes::Ldind_R8 );
   mthdIL->Emit( OpCodes::Ldarg_2 );
   mthdIL->Emit( OpCodes::Sub );
   mthdIL->Emit( OpCodes::Stind_R8 );
   mthdIL->Emit( OpCodes::Ldarg_0 );
   mthdIL->Emit( OpCodes::Ldarg_0 );
   mthdIL->Emit( OpCodes::Ldfld, balanceAmtBldr );
   mthdIL->Emit( OpCodes::Ldarg_2 );
   mthdIL->Emit( OpCodes::Add );
   mthdIL->Emit( OpCodes::Stfld, balanceAmtBldr );
   mthdIL->Emit( OpCodes::Ldarg_0 );
   mthdIL->Emit( OpCodes::Ldfld, balanceAmtBldr );
   mthdIL->Emit( OpCodes::Ret );
   return myTypeBuilder->CreateType();
}

int main()
{
   Type^ custType = nullptr;
   Object^ custObj = nullptr;
   array<Type^>^custArgTypes = {String::typeid,String::typeid,double::typeid};
   
   // Call the method to build our dynamic class.
   custType = BuildCustomerDataType();
   Console::WriteLine( "---" );
   ConstructorInfo^ myCustCtor = custType->GetConstructor( custArgTypes );
   double initialBalance = 100.00;
   array<Object^>^temp5 = {"Joe Consumer","5678-XYZ",initialBalance};
   custObj = myCustCtor->Invoke( temp5 );
   array<MemberInfo^>^myMemberInfo = custType->GetMember( "AddFundsFromPool" );
   double thePool = 1000.00;
   Console::WriteLine( "The pool is currently ${0}", thePool );
   Console::WriteLine( "The original balance of the account instance is ${0}", initialBalance );
   double amountFromPool = 50.00;
   Console::WriteLine( "The amount to be subtracted from the pool and added to the account is ${0}", amountFromPool );
   Console::WriteLine( "---" );
   Console::WriteLine( "Calling {0} ...", myMemberInfo[ 0 ] );
   Console::WriteLine( "---" );
   array<Object^>^passMe = {thePool,amountFromPool};
   Console::WriteLine( "The new balance in the account instance is ${0}", custType->InvokeMember( "AddFundsFromPool", BindingFlags::InvokeMethod, nullptr, custObj, passMe ) );
   thePool = safe_cast<double>(passMe[ 0 ]);
   Console::WriteLine( "The new amount in the pool is ${0}", thePool );
}

using System;
using System.Threading;
using System.Reflection;
using System.Reflection.Emit;

class ParamBuilderDemo 

{

   public static Type BuildCustomerDataType()
   {

    AppDomain myDomain = Thread.GetDomain();
    AssemblyName myAsmName = new AssemblyName();
    myAsmName.Name = "MyDynamicAssembly";

    AssemblyBuilder myAsmBuilder = myDomain.DefineDynamicAssembly(myAsmName,
                        AssemblyBuilderAccess.Run);

    ModuleBuilder myModBuilder = myAsmBuilder.DefineDynamicModule("MyMod");

    TypeBuilder myTypeBuilder = myModBuilder.DefineType("CustomerData",
                        TypeAttributes.Public);

    FieldBuilder customerNameBldr = myTypeBuilder.DefineField("customerName",
                            typeof(string),
                            FieldAttributes.Private);
    FieldBuilder acctIDBldr = myTypeBuilder.DefineField("acctID",
                            typeof(string),
                            FieldAttributes.Private);
    FieldBuilder balanceAmtBldr = myTypeBuilder.DefineField("balanceAmt",
                            typeof(double),
                            FieldAttributes.Private);
                                
    ConstructorBuilder myCtorBuilder = myTypeBuilder.DefineConstructor(
                            MethodAttributes.Public,
                            CallingConventions.HasThis, 
                            new Type[] { typeof(string),
                                     typeof(string),
                                     typeof(double) });


    ILGenerator ctorIL = myCtorBuilder.GetILGenerator();

    Type objType = Type.GetType("System.Object"); 
        ConstructorInfo objCtor = objType.GetConstructor(new Type[] {});

    ctorIL.Emit(OpCodes.Ldarg_0);
    ctorIL.Emit(OpCodes.Call, objCtor);

    ctorIL.Emit(OpCodes.Ldarg_0);
    ctorIL.Emit(OpCodes.Ldarg_1);
    ctorIL.Emit(OpCodes.Stfld, customerNameBldr);

    ctorIL.Emit(OpCodes.Ldarg_0);
    ctorIL.Emit(OpCodes.Ldarg_2);
    ctorIL.Emit(OpCodes.Stfld, acctIDBldr);

    ctorIL.Emit(OpCodes.Ldarg_0);
    ctorIL.Emit(OpCodes.Ldarg_3);
    ctorIL.Emit(OpCodes.Stfld, balanceAmtBldr);

    ctorIL.Emit(OpCodes.Ret);

    // This method will take an amount from a static pool and add it to the balance.
       
    // Note that we are passing the first parameter, fundsPool, by reference. Therefore,
    // we need to inform the MethodBuilder to expect a ref, by declaring the first
    // parameter's type to be System.Double& (a reference to a double).
 
    MethodBuilder myMthdBuilder = myTypeBuilder.DefineMethod("AddFundsFromPool",
                        MethodAttributes.Public,
                        typeof(double),
                        new Type[] { Type.GetType("System.Double&"),
                                 typeof(double) });

    ParameterBuilder poolRefBuilder = myMthdBuilder.DefineParameter(1,
                        ParameterAttributes.Out,
                        "fundsPool");

    ParameterBuilder amountFromPoolBuilder = myMthdBuilder.DefineParameter(2,
                        ParameterAttributes.In,
                            "amountFromPool");

    ILGenerator mthdIL = myMthdBuilder.GetILGenerator();

    mthdIL.Emit(OpCodes.Ldarg_1); 
    mthdIL.Emit(OpCodes.Ldarg_1); 
    mthdIL.Emit(OpCodes.Ldind_R8);
    mthdIL.Emit(OpCodes.Ldarg_2);
    mthdIL.Emit(OpCodes.Sub);

    mthdIL.Emit(OpCodes.Stind_R8);

    mthdIL.Emit(OpCodes.Ldarg_0);
    mthdIL.Emit(OpCodes.Ldarg_0);
    mthdIL.Emit(OpCodes.Ldfld, balanceAmtBldr);
    mthdIL.Emit(OpCodes.Ldarg_2);
    mthdIL.Emit(OpCodes.Add);

    mthdIL.Emit(OpCodes.Stfld, balanceAmtBldr);

    mthdIL.Emit(OpCodes.Ldarg_0);
    mthdIL.Emit(OpCodes.Ldfld, balanceAmtBldr);
    mthdIL.Emit(OpCodes.Ret);

    return myTypeBuilder.CreateType();

   }

   public static void Main()
   {
    Type custType = null;
    object custObj = null;

    Type[] custArgTypes = new Type[] {typeof(string), typeof(string), typeof(double)};
    
    // Call the method to build our dynamic class.

    custType = BuildCustomerDataType();

    Console.WriteLine("---");

    ConstructorInfo myCustCtor = custType.GetConstructor(custArgTypes);
    double initialBalance = 100.00;
    custObj = myCustCtor.Invoke(new object[] { "Joe Consumer", 
                           "5678-XYZ", 
                           initialBalance });

    MemberInfo[] myMemberInfo = custType.GetMember("AddFundsFromPool");


    double thePool = 1000.00;
    Console.WriteLine("The pool is currently ${0}", thePool);
    Console.WriteLine("The original balance of the account instance is ${0}",
                            initialBalance);

    double amountFromPool = 50.00;
    Console.WriteLine("The amount to be subtracted from the pool and added " +
              "to the account is ${0}", amountFromPool);
    
    Console.WriteLine("---");
    Console.WriteLine("Calling {0} ...", myMemberInfo[0].ToString());
    Console.WriteLine("---");

    object[] passMe = new object[] { thePool, amountFromPool };
    Console.WriteLine("The new balance in the account instance is ${0}",
                    custType.InvokeMember("AddFundsFromPool",
                    BindingFlags.InvokeMethod,
                    null, custObj, passMe));
    thePool = (double)passMe[0];
    Console.WriteLine("The new amount in the pool is ${0}", thePool);

   }

}


Imports System.Threading
Imports System.Reflection
Imports System.Reflection.Emit

 _

Class ParamBuilderDemo
   
   Public Shared Function BuildCustomerDataType() As Type
      
      Dim myDomain As AppDomain = Thread.GetDomain()
      Dim myAsmName As New AssemblyName()
      myAsmName.Name = "MyDynamicAssembly"
      
      Dim myAsmBuilder As AssemblyBuilder = myDomain.DefineDynamicAssembly(myAsmName, _
                        AssemblyBuilderAccess.Run)
      
      Dim myModBuilder As ModuleBuilder = myAsmBuilder.DefineDynamicModule("MyMod")
      
      Dim myTypeBuilder As TypeBuilder = myModBuilder.DefineType("CustomerData", TypeAttributes.Public)
      
      Dim customerNameBldr As FieldBuilder = myTypeBuilder.DefineField("customerName", _
                                GetType(String), _
                                FieldAttributes.Private)
      Dim acctIDBldr As FieldBuilder = myTypeBuilder.DefineField("acctID", _
                                GetType(String), _
                                FieldAttributes.Private)
      Dim balanceAmtBldr As FieldBuilder = myTypeBuilder.DefineField("balanceAmt", _
                                GetType(Double), _
                                FieldAttributes.Private)
      
      Dim myCtorBuilder As ConstructorBuilder = myTypeBuilder.DefineConstructor(MethodAttributes.Public, _
                                CallingConventions.HasThis, _
                                New Type() {GetType(String), _
                                        GetType(String), _
                                        GetType(Double)})
      
      
      Dim ctorIL As ILGenerator = myCtorBuilder.GetILGenerator()
      
      Dim objType As Type = Type.GetType("System.Object")
      Dim objCtor As ConstructorInfo = objType.GetConstructor(New Type(){})
      
      ctorIL.Emit(OpCodes.Ldarg_0)
      ctorIL.Emit(OpCodes.Call, objCtor)
      
      ctorIL.Emit(OpCodes.Ldarg_0)
      ctorIL.Emit(OpCodes.Ldarg_1)
      ctorIL.Emit(OpCodes.Stfld, customerNameBldr)
      
      ctorIL.Emit(OpCodes.Ldarg_0)
      ctorIL.Emit(OpCodes.Ldarg_2)
      ctorIL.Emit(OpCodes.Stfld, acctIDBldr)
      
      ctorIL.Emit(OpCodes.Ldarg_0)
      ctorIL.Emit(OpCodes.Ldarg_3)
      ctorIL.Emit(OpCodes.Stfld, balanceAmtBldr)
      
      ctorIL.Emit(OpCodes.Ret)
      
      ' This method will take an amount from a static pool and add it to the balance.
      ' Note that we are passing the first parameter, fundsPool, by reference. Therefore,
      ' we need to inform the MethodBuilder to expect a ref, by declaring the first
      ' parameter's type to be System.Double& (a reference to a double).

      Dim myMthdBuilder As MethodBuilder = myTypeBuilder.DefineMethod("AddFundsFromPool", _
                                MethodAttributes.Public, _
                                GetType(Double), _
                                New Type() {Type.GetType("System.Double&"), _
                                         GetType(Double)})
      
      Dim poolRefBuilder As ParameterBuilder = myMthdBuilder.DefineParameter(1, _
                            ParameterAttributes.Out, "fundsPool")
      
      Dim amountFromPoolBuilder As ParameterBuilder = myMthdBuilder.DefineParameter(2, _
                            ParameterAttributes.In, "amountFromPool")
      
      Dim mthdIL As ILGenerator = myMthdBuilder.GetILGenerator()
      
      mthdIL.Emit(OpCodes.Ldarg_1)
      mthdIL.Emit(OpCodes.Ldarg_1)
      mthdIL.Emit(OpCodes.Ldind_R8)
      mthdIL.Emit(OpCodes.Ldarg_2)
      mthdIL.Emit(OpCodes.Sub)
      
      mthdIL.Emit(OpCodes.Stind_R8)
      
      mthdIL.Emit(OpCodes.Ldarg_0)
      mthdIL.Emit(OpCodes.Ldarg_0)
      mthdIL.Emit(OpCodes.Ldfld, balanceAmtBldr)
      mthdIL.Emit(OpCodes.Ldarg_2)
      mthdIL.Emit(OpCodes.Add)
      
      mthdIL.Emit(OpCodes.Stfld, balanceAmtBldr)
      
      mthdIL.Emit(OpCodes.Ldarg_0)
      mthdIL.Emit(OpCodes.Ldfld, balanceAmtBldr)
      mthdIL.Emit(OpCodes.Ret)
      
      Return myTypeBuilder.CreateType()

   End Function 'BuildCustomerDataType
    
   
   Public Shared Sub Main()

      Dim custType As Type = Nothing
      Dim custObj As Object = Nothing
      
      Dim custArgTypes() As Type = {GetType(String), GetType(String), GetType(Double)}
      
      ' Call the method to build our dynamic class.
      custType = BuildCustomerDataType()
      
      Console.WriteLine("---")
      
      Dim myCustCtor As ConstructorInfo = custType.GetConstructor(custArgTypes)
      Dim initialBalance As Double = 100.0
      custObj = myCustCtor.Invoke(New Object() {"Joe Consumer", "5678-XYZ", initialBalance})
      
      Dim myMemberInfo As MemberInfo() = custType.GetMember("AddFundsFromPool")
      
      
      Dim thePool As Double = 1000.0
      Console.WriteLine("The pool is currently ${0}", thePool)
      Console.WriteLine("The original balance of the account instance is ${0}", initialBalance)
      
      Dim amountFromPool As Double = 50.0
      Console.WriteLine("The amount to be subtracted from the pool and added " & _
            "to the account is ${0}", amountFromPool)
      
      Console.WriteLine("---")
      Console.WriteLine("Calling {0} ...", myMemberInfo(0).ToString())
      Console.WriteLine("---")
      
      Dim passMe() As Object = {thePool, amountFromPool}
      Console.WriteLine("The new balance in the account instance is ${0}", _
                custType.InvokeMember("AddFundsFromPool", _
                BindingFlags.InvokeMethod, Nothing, custObj, passMe))
      thePool = CDbl(passMe(0))
      Console.WriteLine("The new amount in the pool is ${0}", thePool)

   End Sub

End Class

Remarks

Parameter attributes need to consistent with the method signature. If you specify Out attributes for a parameter, you should ensure that the type of that method parameter is a ByRef type.

Some ParameterBuilder attributes require that you call DefineMethod with viable parameters in order for the Microsoft intermediate language (MSIL) to work correctly at runtime. For example, if you define a ParameterBuilder with ParameterAttributes.Out for parameter 1 of a MethodBuilder, then parameter 1 of MethodBuilder must be a reference such as Type.GetType("System.String&"), rather than Type.GetType("System.String").

Properties

Attributes

Retrieves the attributes for this parameter.

IsIn

Retrieves whether this is an input parameter.

IsOptional

Retrieves whether this parameter is optional.

IsOut

Retrieves whether this parameter is an output parameter.

Name

Retrieves the name of this parameter.

Position

Retrieves the signature position for this parameter.

Methods

Equals(Object)

Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetHashCode()

Serves as the default hash function.

(Inherited from Object)
GetToken()

Retrieves the token for this parameter.

GetType()

Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
SetConstant(Object)

Sets the default value of the parameter.

SetCustomAttribute(ConstructorInfo, Byte[])

Set a custom attribute using a specified custom attribute blob.

SetCustomAttribute(CustomAttributeBuilder)

Set a custom attribute using a custom attribute builder.

SetMarshal(UnmanagedMarshal)

Specifies the marshaling for this parameter.

ToString()

Returns a string that represents the current object.

(Inherited from Object)

Explicit Interface Implementations

_ParameterBuilder.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)

Maps a set of names to a corresponding set of dispatch identifiers.

_ParameterBuilder.GetTypeInfo(UInt32, UInt32, IntPtr)

Retrieves the type information for an object, which can then be used to get the type information for an interface.

_ParameterBuilder.GetTypeInfoCount(UInt32)

Retrieves the number of type information interfaces that an object provides (either 0 or 1).

_ParameterBuilder.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

Provides access to properties and methods exposed by an object.

Applies to