本文整理汇总了VB.NET中System.Reflection.Emit.OpCodes.Switch字段的典型用法代码示例。如果您正苦于以下问题：VB.NET OpCodes.Switch字段的具体用法？VB.NET OpCodes.Switch怎么用？VB.NET OpCodes.Switch使用的例子？那么恭喜您, 这里精选的字段代码示例或许可以为您提供帮助。您也可以进一步了解该字段所在类System.Reflection.Emit.OpCodes的用法示例。
在下文中一共展示了OpCodes.Switch字段的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的VB.NET代码示例。
示例1: DynamicJumpTableDemo
' 导入命名空间
Imports System.Threading
Imports System.Reflection
Imports System.Reflection.Emit
_
Class DynamicJumpTableDemo
Public Shared Function BuildMyType() 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("MyJumpTableDemo")
Dim myTypeBuilder As TypeBuilder = myModBuilder.DefineType("JumpTableDemo", _
TypeAttributes.Public)
Dim myMthdBuilder As MethodBuilder = myTypeBuilder.DefineMethod("SwitchMe", _
MethodAttributes.Public Or MethodAttributes.Static, _
GetType(String), New Type() {GetType(Integer)})
Dim myIL As ILGenerator = myMthdBuilder.GetILGenerator()
Dim defaultCase As Label = myIL.DefineLabel()
Dim endOfMethod As Label = myIL.DefineLabel()
' We are initializing our jump table. Note that the labels
' will be placed later using the MarkLabel method.
Dim jumpTable() As Label = {myIL.DefineLabel(), _
myIL.DefineLabel(), _
myIL.DefineLabel(), _
myIL.DefineLabel(), _
myIL.DefineLabel()}
' arg0, the number we passed, is pushed onto the stack.
' In this case, due to the design of the code sample,
' the value pushed onto the stack happens to match the
' index of the label (in IL terms, the index of the offset
' in the jump table). If this is not the case, such as
' when switching based on non-integer values, rules for the correspondence
' between the possible case values and each index of the offsets
' must be established outside of the ILGenerator.Emit calls,
' much as a compiler would.
myIL.Emit(OpCodes.Ldarg_0)
myIL.Emit(OpCodes.Switch, jumpTable)
' Branch on default case
myIL.Emit(OpCodes.Br_S, defaultCase)
' Case arg0 = 0
myIL.MarkLabel(jumpTable(0))
myIL.Emit(OpCodes.Ldstr, "are no bananas")
myIL.Emit(OpCodes.Br_S, endOfMethod)
' Case arg0 = 1
myIL.MarkLabel(jumpTable(1))
myIL.Emit(OpCodes.Ldstr, "is one banana")
myIL.Emit(OpCodes.Br_S, endOfMethod)
' Case arg0 = 2
myIL.MarkLabel(jumpTable(2))
myIL.Emit(OpCodes.Ldstr, "are two bananas")
myIL.Emit(OpCodes.Br_S, endOfMethod)
' Case arg0 = 3
myIL.MarkLabel(jumpTable(3))
myIL.Emit(OpCodes.Ldstr, "are three bananas")
myIL.Emit(OpCodes.Br_S, endOfMethod)
' Case arg0 = 4
myIL.MarkLabel(jumpTable(4))
myIL.Emit(OpCodes.Ldstr, "are four bananas")
myIL.Emit(OpCodes.Br_S, endOfMethod)
' Default case
myIL.MarkLabel(defaultCase)
myIL.Emit(OpCodes.Ldstr, "are many bananas")
myIL.MarkLabel(endOfMethod)
myIL.Emit(OpCodes.Ret)
Return myTypeBuilder.CreateType()
End Function 'BuildMyType
Public Shared Sub Main()
Dim myType As Type = BuildMyType()
Console.Write("Enter an integer between 0 and 5: ")
Dim theValue As Integer = Convert.ToInt32(Console.ReadLine())
Console.WriteLine("---")
Dim myInstance As [Object] = Activator.CreateInstance(myType, New Object() {})
Console.WriteLine("Yes, there {0} today!", myType.InvokeMember("SwitchMe", _
BindingFlags.InvokeMethod, Nothing, _
myInstance, New Object() {theValue}))
End Sub
End Class