CodeTypeParameter Classe
Definizione
Importante
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Rappresenta un parametro del tipo di un tipo o metodo generico.
public ref class CodeTypeParameter : System::CodeDom::CodeObjectpublic class CodeTypeParameter : System.CodeDom.CodeObject[System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.AutoDispatch)]
[System.Runtime.InteropServices.ComVisible(true)]
[System.Serializable]
public class CodeTypeParameter : System.CodeDom.CodeObjecttype CodeTypeParameter = class
inherit CodeObject[<System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.AutoDispatch)>]
[<System.Runtime.InteropServices.ComVisible(true)>]
[<System.Serializable>]
type CodeTypeParameter = class
inherit CodeObjectPublic Class CodeTypeParameter
Inherits CodeObject- Ereditarietà
- Attributi
Esempio
Nell'esempio di codice seguente viene illustrato l'uso della CodeTypeParameter classe per creare un grafo CodeDOM per generare un'applicazione contenente codice generics.
using System.CodeDom;
using System.CodeDom.Compiler;
using System.Collections;
using System.Collections.Specialized;
using System.IO;
using System.Reflection;
using System.Text.RegularExpressions;
using System.Globalization;
using System.Collections.Generic;
namespace System.CodeDom
{
class CodeDomGenericsDemo
{
static void Main()
{
try
{
CreateGenericsCode("cs", "Generic.cs", "GenericCS.exe");
}
catch (Exception e)
{
LogMessage("Unexpected Exception:" + e.ToString());
}
}
static void CreateGenericsCode(string providerName, string sourceFileName, string assemblyName)
{
CodeDomProvider provider = CodeDomProvider.CreateProvider(providerName);
LogMessage("Building CodeDOM graph...");
CodeCompileUnit cu = new CodeCompileUnit();
CreateGraph(provider, cu);
StringWriter sw = new StringWriter();
LogMessage("Generating code...");
provider.GenerateCodeFromCompileUnit(cu, sw, null);
string output = sw.ToString();
output = Regex.Replace(output, "Runtime Version:[^\r\n]*",
"Runtime Version omitted for demo");
LogMessage("Dumping source...");
LogMessage(output);
LogMessage("Writing source to file...");
Stream s = File.Open(sourceFileName, FileMode.Create);
StreamWriter t = new StreamWriter(s);
t.Write(output);
t.Close();
s.Close();
CompilerParameters opt = 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;
CompilerResults results;
LogMessage("Compiling with " + providerName);
results = provider.CompileAssemblyFromFile(opt, sourceFileName);
OutputResults(results);
if (results.NativeCompilerReturnValue != 0)
{
LogMessage("");
LogMessage("Compilation failed.");
}
else
{
LogMessage("");
LogMessage("Demo completed successfully.");
}
File.Delete(sourceFileName);
}
// Create a CodeDOM graph.
static void CreateGraph(CodeDomProvider provider, CodeCompileUnit cu)
{
if (!provider.Supports(GeneratorSupport.GenericTypeReference |
GeneratorSupport.GenericTypeDeclaration))
{
// Return if the generator does not support generics.
return;
}
CodeNamespace ns = 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.
CodeTypeDeclaration class1 = new CodeTypeDeclaration();
class1.Name = "MyDictionary";
class1.BaseTypes.Add(new CodeTypeReference("Dictionary",
new CodeTypeReference[] {
new CodeTypeReference("TKey"),
new CodeTypeReference("TValue"),
}));
CodeTypeParameter kType = new CodeTypeParameter("TKey");
kType.HasConstructorConstraint = true;
kType.Constraints.Add(new CodeTypeReference(typeof(IComparable)));
kType.CustomAttributes.Add(new CodeAttributeDeclaration(
"System.ComponentModel.DescriptionAttribute",
new CodeAttributeArgument(new CodePrimitiveExpression("KeyType"))));
CodeTypeReference iComparableT = new CodeTypeReference("IComparable");
iComparableT.TypeArguments.Add(new CodeTypeReference(kType));
kType.Constraints.Add(iComparableT);
CodeTypeParameter vType = new CodeTypeParameter("TValue");
vType.Constraints.Add(new CodeTypeReference(typeof(IList<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.
CodeMemberMethod printMethod = new CodeMemberMethod();
CodeTypeParameter sType = new CodeTypeParameter("S");
sType.HasConstructorConstraint = true;
CodeTypeParameter tType = new CodeTypeParameter("T");
sType.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);
CodeTypeDeclaration class2 = new CodeTypeDeclaration();
class2.Name = "Demo";
CodeEntryPointMethod methodMain = new CodeEntryPointMethod();
CodeTypeReference myClass = new CodeTypeReference(
"MyDictionary",
new CodeTypeReference[] {
new CodeTypeReference(typeof(int)),
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[0])));
string dictionaryTypeName = typeof(System.Collections.Generic.Dictionary<int,
System.Collections.Generic.List<string>>[]).FullName;
CodeTypeReference dictionaryType = new CodeTypeReference(dictionaryTypeName);
methodMain.Statements.Add(
new CodeVariableDeclarationStatement(dictionaryType, "dict2",
new CodeArrayCreateExpression(dictionaryType, new CodeExpression[1] { new CodePrimitiveExpression(null) })));
methodMain.Statements.Add(ConsoleWriteLineStatement(
new CodePropertyReferenceExpression(
new CodeVariableReferenceExpression("dict2"),
"Length")));
class2.Members.Add(methodMain);
ns.Types.Add(class2);
}
static CodeStatement ConsoleWriteLineStatement(CodeExpression exp)
{
return new CodeExpressionStatement(
new CodeMethodInvokeExpression(
new CodeMethodReferenceExpression(
new CodeTypeReferenceExpression(new CodeTypeReference("Console")),
"WriteLine"),
new CodeExpression[]{
exp,
}));
}
static CodeStatement ConsoleWriteLineStatement(string text)
{
return ConsoleWriteLineStatement(new CodePrimitiveExpression(text));
}
static void LogMessage(string text)
{
Console.WriteLine(text);
}
static void OutputResults(CompilerResults results)
{
LogMessage("NativeCompilerReturnValue=" +
results.NativeCompilerReturnValue.ToString());
foreach (string s in results.Output)
{
LogMessage(s);
}
}
}
}
// This example generates the following code:
//------------------------------------------------------------------------------
// <auto-generated>
// This code was generated by a tool.
// Runtime Version omitted for demo
//
// Changes to this file may cause incorrect behavior and will be lost if
// the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------
//namespace DemoNamespace
//{
// using System;
// using System.Collections.Generic;
// public class MyDictionary<[System.ComponentModel.DescriptionAttribute("KeyType")] TKey,
// [System.ComponentModel.DescriptionAttribute("ValueType")] TValue> : Dictionary<TKey, TValue>
// where TKey : System.IComparable, IComparable<TKey>, new()
// where TValue : System.Collections.Generic.IList<string>
// {
// public virtual void Print<S, T>()
// where S : new()
// {
// Console.WriteLine(default(T));
// Console.WriteLine(default(S));
// }
// }
// public class Demo
// {
// public static void Main()
// {
// MyDictionary<int, List<string>> dict = new MyDictionary<int, List<string>>();
// Console.WriteLine(dict.Count);
// dict.Print<decimal, int>();
// System.Collections.Generic.Dictionary<int, System.Collections.Generic.List<string>>[] dict2 =
// new System.Collections.Generic.Dictionary<int, System.Collections.Generic.List<string>>[] { null };
// Console.WriteLine(dict2.Length);
// }
// }
//}
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
Commenti
La CodeTypeParameter classe rappresenta un parametro di tipo nella dichiarazione di un tipo o di un metodo generico.
Una dichiarazione di tipo o metodo generico contiene uno o più tipi non specificati noti come parametri di tipo. Un nome di parametro di tipo indica il tipo all'interno del corpo della dichiarazione generica. Ad esempio, la dichiarazione generica per la List<T> classe contiene il parametro Tdi tipo .
Per altre informazioni sui generics, vedere Generics nella libreria di classi .NET Framework.
Costruttori
| CodeTypeParameter() |
Inizializza una nuova istanza della classe CodeTypeParameter. |
| CodeTypeParameter(String) |
Inizializza una nuova istanza della classe CodeTypeParameter con il nome del parametro del tipo specificato. |
Proprietà
| Constraints |
Ottiene i vincoli per il parametro del tipo. |
| CustomAttributes |
Ottiene gli attributi personalizzati per il parametro del tipo. |
| HasConstructorConstraint |
Ottiene o imposta un valore che indica se al parametro del tipo è associato un vincolo constructor. |
| Name |
Ottiene o imposta il nome del parametro del tipo. |
| UserData |
Ottiene i dati definibili dall'utente per l'oggetto corrente. (Ereditato da CodeObject) |
Metodi
| Equals(Object) |
Determina se l'oggetto specificato è uguale all'oggetto corrente. (Ereditato da Object) |
| GetHashCode() |
Funge da funzione hash predefinita. (Ereditato da Object) |
| GetType() |
Ottiene l'oggetto Type dell'istanza corrente. (Ereditato da Object) |
| MemberwiseClone() |
Crea una copia superficiale dell'oggetto Object corrente. (Ereditato da Object) |
| ToString() |
Restituisce una stringa che rappresenta l'oggetto corrente. (Ereditato da Object) |
Si applica a
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