' 导入命名空间
Imports System.CodeDom
Imports System.CodeDom.Compiler
Imports System.Collections
Imports System.Collections.Specialized
Imports System.IO
Imports System.Reflection
Imports System.Text.RegularExpressions
Imports System.Globalization
Imports System.Collections.Generic
Class CodeDomGenericsDemo
Shared Sub Main()
Try
CreateGenericsCode("vb", "Generic.vb", "GenericVB.exe")
Catch e As Exception
LogMessage(("Unexpected Exception:" + e.ToString()))
End Try
End Sub
Shared Sub CreateGenericsCode(ByVal providerName As String, ByVal sourceFileName As String, ByVal assemblyName As String)
Dim provider As CodeDomProvider = CodeDomProvider.CreateProvider(providerName)
LogMessage("Building CodeDOM graph...")
Dim cu As New CodeCompileUnit()
CreateGraph(provider, cu)
Dim sw As New StringWriter()
LogMessage("Generating code...")
provider.GenerateCodeFromCompileUnit(cu, sw, Nothing)
Dim output As String = sw.ToString()
output = Regex.Replace(output, "Runtime version:[^" + vbCr + vbLf + "]*", "Runtime version omitted for demo")
LogMessage("Displaying source code...")
LogMessage(output)
LogMessage("Writing source code to file...")
Dim s As Stream = File.Open(sourceFileName, FileMode.Create)
Dim t As New StreamWriter(s)
t.Write(output)
t.Close()
s.Close()
Dim opt As New CompilerParameters(New String() {"System.dll", "System.Xml.dll", "System.Windows.Forms.dll", "System.Data.dll", "System.Drawing.dll"})
opt.GenerateExecutable = False
opt.TreatWarningsAsErrors = True
opt.IncludeDebugInformation = True
opt.GenerateInMemory = True
Dim results As CompilerResults
LogMessage(("Compiling with provider " + providerName))
results = provider.CompileAssemblyFromFile(opt, sourceFileName)
OutputResults(results)
If results.NativeCompilerReturnValue <> 0 Then
LogMessage("")
LogMessage("Compilation failed.")
Else
LogMessage("")
LogMessage("Demo completed successfully.")
End If
File.Delete(sourceFileName)
End Sub
' Create a CodeDOM graph.
Shared Sub CreateGraph(ByVal provider As CodeDomProvider, ByVal cu As CodeCompileUnit)
' Determine if the generator supports generics.
If Not provider.Supports(GeneratorSupport.GenericTypeReference Or GeneratorSupport.GenericTypeDeclaration) Then
' Return if the generator does not support generics.
Return
End If
Dim ns As New CodeNamespace("DemoNamespace")
ns.Imports.Add(New CodeNamespaceImport("System"))
ns.Imports.Add(New CodeNamespaceImport("System.Collections.Generic"))
cu.Namespaces.Add(ns)
' Declare a generic class.
Dim class1 As New CodeTypeDeclaration()
class1.Name = "MyDictionary"
class1.BaseTypes.Add( _
New CodeTypeReference("Dictionary", _
New CodeTypeReference() {New CodeTypeReference("TKey"), _
New CodeTypeReference("TValue")}))
Dim kType As New CodeTypeParameter("TKey")
kType.HasConstructorConstraint = True
kType.Constraints.Add(New CodeTypeReference(GetType(IComparable)))
kType.CustomAttributes.Add _
(New CodeAttributeDeclaration("System.ComponentModel.DescriptionAttribute", _
New CodeAttributeArgument(New CodePrimitiveExpression("KeyType"))))
Dim iComparableT As New CodeTypeReference("IComparable")
iComparableT.TypeArguments.Add(New CodeTypeReference(kType))
kType.Constraints.Add(iComparableT)
Dim vType As New CodeTypeParameter("TValue")
vType.Constraints.Add(New CodeTypeReference(GetType(IList(Of System.String))))
vType.CustomAttributes.Add _
(New CodeAttributeDeclaration("System.ComponentModel.DescriptionAttribute", _
New CodeAttributeArgument(New CodePrimitiveExpression("ValueType"))))
class1.TypeParameters.Add(kType)
class1.TypeParameters.Add(vType)
ns.Types.Add(class1)
' Declare a generic method.
Dim printMethod As New CodeMemberMethod()
Dim sType As New CodeTypeParameter("S")
sType.HasConstructorConstraint = True
Dim tType As New CodeTypeParameter("T")
tType.HasConstructorConstraint = True
printMethod.Name = "Print"
printMethod.TypeParameters.Add(sType)
printMethod.TypeParameters.Add(tType)
printMethod.Statements.Add(ConsoleWriteLineStatement _
(New CodeDefaultValueExpression(New CodeTypeReference("T"))))
printMethod.Statements.Add(ConsoleWriteLineStatement _
(New CodeDefaultValueExpression(New CodeTypeReference("S"))))
printMethod.Attributes = MemberAttributes.Public
class1.Members.Add(printMethod)
Dim class2 As New CodeTypeDeclaration()
class2.Name = "Demo"
Dim methodMain As New CodeEntryPointMethod()
Dim [myClass] As New CodeTypeReference("MyDictionary", _
New CodeTypeReference() {New CodeTypeReference(GetType(Integer)), _
New CodeTypeReference("List", _
New CodeTypeReference() {New CodeTypeReference("System.String")})})
methodMain.Statements.Add(New CodeVariableDeclarationStatement([myClass], _
"dict", New CodeObjectCreateExpression([myClass])))
methodMain.Statements.Add(ConsoleWriteLineStatement _
(New CodePropertyReferenceExpression _
(New CodeVariableReferenceExpression("dict"), "Count")))
methodMain.Statements.Add _
(New CodeExpressionStatement _
(New CodeMethodInvokeExpression _
(New CodeMethodReferenceExpression _
(New CodeVariableReferenceExpression("dict"), _
"Print", New CodeTypeReference() _
{New CodeTypeReference("System.Decimal"), _
New CodeTypeReference("System.Int32")}), _
New CodeExpression(-1) {})))
Dim longTypeName As String = GetType( _
System.Collections.Generic.Dictionary(Of Integer, _
System.Collections.Generic.List(Of String))()).FullName
Dim longType As New CodeTypeReference(longTypeName)
methodMain.Statements.Add(New CodeVariableDeclarationStatement _
(longType, "dict2", New CodeArrayCreateExpression _
(longType, New CodeExpression(0) {New CodePrimitiveExpression(Nothing)})))
methodMain.Statements.Add(ConsoleWriteLineStatement(New CodePropertyReferenceExpression(New CodeVariableReferenceExpression("dict2"), "Length")))
class2.Members.Add(methodMain)
ns.Types.Add(class2)
End Sub
Overloads Shared Function ConsoleWriteLineStatement(ByVal exp As CodeExpression) As CodeStatement
Return New CodeExpressionStatement(New CodeMethodInvokeExpression _
(New CodeMethodReferenceExpression _
(New CodeTypeReferenceExpression _
(New CodeTypeReference("Console")), "WriteLine"), _
New CodeExpression() {exp}))
End Function 'ConsoleWriteLineStatement
Overloads Shared Function ConsoleWriteLineStatement(ByVal [text] As String) As CodeStatement
Return ConsoleWriteLineStatement(New CodePrimitiveExpression([text]))
End Function 'ConsoleWriteLineStatement
Shared Sub LogMessage(ByVal [text] As String)
Console.WriteLine([text])
End Sub
Shared Sub OutputResults(ByVal results As CompilerResults)
LogMessage(("NativeCompilerReturnValue=" + results.NativeCompilerReturnValue.ToString()))
Dim s As String
For Each s In results.Output
LogMessage(s)
Next s
End Sub
End Class
'
' This example generates the following code:
'------------------------------------------------------------------------------
' <auto-generated>
' This code was generated by a tool.
' Runtime Version:2.0.50727.1434
'
' Changes to this file may cause incorrect behavior and will be lost if
' the code is regenerated.
' </auto-generated>
'------------------------------------------------------------------------------
'Option Strict Off
'Option Explicit On
''Imports System.Collections.Generic
'Namespace DemoNamespace
' Public Class MyDictionary(Of TKey As {System.IComparable, IComparable(Of TKey), New}, TValue As System.Collections.
'Generic.IList(Of String))
' Inherits Dictionary(Of TKey, TValue)
' Public Overridable Sub Print(Of S As New, T As New)()
' Console.WriteLine(CType(Nothing, T))
' Console.WriteLine(CType(Nothing, S))
' End Sub
' End Class
' Public Class Demo
' Public Shared Sub Main()
' Dim dict As MyDictionary(Of Integer, List(Of String)) = New MyDictionary(Of Integer, List(Of String))
' Console.WriteLine(dict.Count)
' dict.Print(Of Decimal, Integer)()
' Dim dict2() As System.Collections.Generic.Dictionary(Of Integer, System.Collections.Generic.List(Of String))
' = New System.Collections.Generic.Dictionary(Of Integer, System.Collections.Generic.List(Of String))() {Nothing}
' Console.WriteLine(dict2.Length)
' End Sub
' End Class
'End Namespace
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