本文整理汇总了VB.NET中System.Reflection.Emit.AssemblyBuilder类的典型用法代码示例。如果您正苦于以下问题:VB.NET AssemblyBuilder类的具体用法?VB.NET AssemblyBuilder怎么用?VB.NET AssemblyBuilder使用的例子?那么, 这里精选的类代码示例或许可以为您提供帮助。
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示例1: DemoAssemblyBuilder
' 导入命名空间
Imports System.Reflection
Imports System.Reflection.Emit
Class DemoAssemblyBuilder
Public Shared Sub Main()
' An assembly consists of one or more modules, each of which
' contains zero or more types. This code creates a single-module
' assembly, the most common case. The module contains one type,
' named "MyDynamicType", that has a private field, a property
' that gets and sets the private field, constructors that
' initialize the private field, and a method that multiplies
' a user-supplied number by the private field value and returns
' the result. The code might look like this in Visual Basic:
'
'Public Class MyDynamicType
' Private m_number As Integer
'
' Public Sub New()
' Me.New(42)
' End Sub
'
' Public Sub New(ByVal initNumber As Integer)
' m_number = initNumber
' End Sub
'
' Public Property Number As Integer
' Get
' Return m_number
' End Get
' Set
' m_Number = Value
' End Set
' End Property
'
' Public Function MyMethod(ByVal multiplier As Integer) As Integer
' Return m_Number * multiplier
' End Function
'End Class
Dim aName As New AssemblyName("DynamicAssemblyExample")
Dim ab As AssemblyBuilder = _
AppDomain.CurrentDomain.DefineDynamicAssembly( _
aName, _
AssemblyBuilderAccess.RunAndSave)
' For a single-module assembly, the module name is usually
' the assembly name plus an extension.
Dim mb As ModuleBuilder = ab.DefineDynamicModule( _
aName.Name, _
aName.Name & ".dll")
Dim tb As TypeBuilder = _
mb.DefineType("MyDynamicType", TypeAttributes.Public)
' Add a private field of type Integer (Int32).
Dim fbNumber As FieldBuilder = tb.DefineField( _
"m_number", _
GetType(Integer), _
FieldAttributes.Private)
' Define a constructor that takes an integer argument and
' stores it in the private field.
Dim parameterTypes() As Type = { GetType(Integer) }
Dim ctor1 As ConstructorBuilder = _
tb.DefineConstructor( _
MethodAttributes.Public, _
CallingConventions.Standard, _
parameterTypes)
Dim ctor1IL As ILGenerator = ctor1.GetILGenerator()
' For a constructor, argument zero is a reference to the new
' instance. Push it on the stack before calling the base
' class constructor. Specify the default constructor of the
' base class (System.Object) by passing an empty array of
' types (Type.EmptyTypes) to GetConstructor.
ctor1IL.Emit(OpCodes.Ldarg_0)
ctor1IL.Emit(OpCodes.Call, _
GetType(Object).GetConstructor(Type.EmptyTypes))
' Push the instance on the stack before pushing the argument
' that is to be assigned to the private field m_number.
ctor1IL.Emit(OpCodes.Ldarg_0)
ctor1IL.Emit(OpCodes.Ldarg_1)
ctor1IL.Emit(OpCodes.Stfld, fbNumber)
ctor1IL.Emit(OpCodes.Ret)
' Define a default constructor that supplies a default value
' for the private field. For parameter types, pass the empty
' array of types or pass Nothing.
Dim ctor0 As ConstructorBuilder = tb.DefineConstructor( _
MethodAttributes.Public, _
CallingConventions.Standard, _
Type.EmptyTypes)
Dim ctor0IL As ILGenerator = ctor0.GetILGenerator()
' For a constructor, argument zero is a reference to the new
' instance. Push it on the stack before pushing the default
' value on the stack, then call constructor ctor1.
ctor0IL.Emit(OpCodes.Ldarg_0)
ctor0IL.Emit(OpCodes.Ldc_I4_S, 42)
ctor0IL.Emit(OpCodes.Call, ctor1)
ctor0IL.Emit(OpCodes.Ret)
' Define a property named Number that gets and sets the private
' field.
'
' 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 the built-in array with no elements: Type.EmptyTypes)
Dim pbNumber As PropertyBuilder = tb.DefineProperty( _
"Number", _
PropertyAttributes.HasDefault, _
GetType(Integer), _
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 Number. The method returns
' an integer and has no arguments. (Note that Nothing could be
' used instead of Types.EmptyTypes)
Dim mbNumberGetAccessor As MethodBuilder = tb.DefineMethod( _
"get_Number", _
getSetAttr, _
GetType(Integer), _
Type.EmptyTypes)
Dim numberGetIL As ILGenerator = mbNumberGetAccessor.GetILGenerator()
' For an instance property, argument zero is the instance. Load the
' instance, then load the private field and return, leaving the
' field value on the stack.
numberGetIL.Emit(OpCodes.Ldarg_0)
numberGetIL.Emit(OpCodes.Ldfld, fbNumber)
numberGetIL.Emit(OpCodes.Ret)
' Define the "set" accessor method for Number, which has no return
' type and takes one argument of type Integer (Int32).
Dim mbNumberSetAccessor As MethodBuilder = _
tb.DefineMethod( _
"set_Number", _
getSetAttr, _
Nothing, _
New Type() { GetType(Integer) })
Dim numberSetIL As ILGenerator = mbNumberSetAccessor.GetILGenerator()
' Load the instance and then the numeric argument, then store the
' argument in the field.
numberSetIL.Emit(OpCodes.Ldarg_0)
numberSetIL.Emit(OpCodes.Ldarg_1)
numberSetIL.Emit(OpCodes.Stfld, fbNumber)
numberSetIL.Emit(OpCodes.Ret)
' Last, map the "get" and "set" accessor methods to the
' PropertyBuilder. The property is now complete.
pbNumber.SetGetMethod(mbNumberGetAccessor)
pbNumber.SetSetMethod(mbNumberSetAccessor)
' Define a method that accepts an integer argument and returns
' the product of that integer and the private field m_number. This
' time, the array of parameter types is created on the fly.
Dim meth As MethodBuilder = tb.DefineMethod( _
"MyMethod", _
MethodAttributes.Public, _
GetType(Integer), _
New Type() { GetType(Integer) })
Dim methIL As ILGenerator = meth.GetILGenerator()
' To retrieve the private instance field, load the instance it
' belongs to (argument zero). After loading the field, load the
' argument one and then multiply. Return from the method with
' the return value (the product of the two numbers) on the
' execution stack.
methIL.Emit(OpCodes.Ldarg_0)
methIL.Emit(OpCodes.Ldfld, fbNumber)
methIL.Emit(OpCodes.Ldarg_1)
methIL.Emit(OpCodes.Mul)
methIL.Emit(OpCodes.Ret)
' Finish the type.
Dim t As Type = tb.CreateType()
' The following line saves the single-module assembly. This
' requires AssemblyBuilderAccess to include Save. You can now
' type "ildasm MyDynamicAsm.dll" at the command prompt, and
' examine the assembly. You can also write a program that has
' a reference to the assembly, and use the MyDynamicType type.
'
ab.Save(aName.Name & ".dll")
' Because AssemblyBuilderAccess includes Run, the code can be
' executed immediately. Start by getting reflection objects for
' the method and the property.
Dim mi As MethodInfo = t.GetMethod("MyMethod")
Dim pi As PropertyInfo = t.GetProperty("Number")
' Create an instance of MyDynamicType using the default
' constructor.
Dim o1 As Object = Activator.CreateInstance(t)
' Display the value of the property, then change it to 127 and
' display it again. Use Nothing to indicate that the property
' has no index.
Console.WriteLine("o1.Number: {0}", pi.GetValue(o1, Nothing))
pi.SetValue(o1, 127, Nothing)
Console.WriteLine("o1.Number: {0}", pi.GetValue(o1, Nothing))
' Call MyMethod, passing 22, and display the return value, 22
' times 127. Arguments must be passed as an array, even when
' there is only one.
Dim arguments() As Object = { 22 }
Console.WriteLine("o1.MyMethod(22): {0}", _
mi.Invoke(o1, arguments))
' Create an instance of MyDynamicType using the constructor
' that specifies m_Number. The constructor is identified by
' matching the types in the argument array. In this case,
' the argument array is created on the fly. Display the
' property value.
Dim o2 As Object = Activator.CreateInstance(t, _
New Object() { 5280 })
Console.WriteLine("o2.Number: {0}", pi.GetValue(o2, Nothing))
End Sub
End Class
输出:
o1.Number: 42 o1.Number: 127 o1.MyMethod(22): 2794 o2.Number: 5280