Type.MakeGenericType(Type[]) Metod
Definition
Viktigt
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Ersätter elementen i en matris med typer för typparametrarna i den aktuella generiska typdefinitionen och returnerar ett Type objekt som representerar den resulterande konstruerade typen.
public:
abstract Type ^ MakeGenericType(... cli::array <Type ^> ^ typeArguments);
public:
virtual Type ^ MakeGenericType(... cli::array <Type ^> ^ typeArguments);
public abstract Type MakeGenericType(params Type[] typeArguments);
[System.Diagnostics.CodeAnalysis.RequiresDynamicCode("The native code for this instantiation might not be available at runtime.")]
[System.Diagnostics.CodeAnalysis.RequiresUnreferencedCode("If some of the generic arguments are annotated (either with DynamicallyAccessedMembersAttribute, or generic constraints), trimming can't validate that the requirements of those annotations are met.")]
public virtual Type MakeGenericType(params Type[] typeArguments);
public virtual Type MakeGenericType(params Type[] typeArguments);
[System.Diagnostics.CodeAnalysis.RequiresUnreferencedCode("If some of the generic arguments are annotated (either with DynamicallyAccessedMembersAttribute, or generic constraints), trimming can't validate that the requirements of those annotations are met.")]
public virtual Type MakeGenericType(params Type[] typeArguments);
abstract member MakeGenericType : Type[] -> Type
[<System.Diagnostics.CodeAnalysis.RequiresDynamicCode("The native code for this instantiation might not be available at runtime.")>]
[<System.Diagnostics.CodeAnalysis.RequiresUnreferencedCode("If some of the generic arguments are annotated (either with DynamicallyAccessedMembersAttribute, or generic constraints), trimming can't validate that the requirements of those annotations are met.")>]
abstract member MakeGenericType : Type[] -> Type
override this.MakeGenericType : Type[] -> Type
abstract member MakeGenericType : Type[] -> Type
override this.MakeGenericType : Type[] -> Type
[<System.Diagnostics.CodeAnalysis.RequiresUnreferencedCode("If some of the generic arguments are annotated (either with DynamicallyAccessedMembersAttribute, or generic constraints), trimming can't validate that the requirements of those annotations are met.")>]
abstract member MakeGenericType : Type[] -> Type
override this.MakeGenericType : Type[] -> Type
Public MustOverride Function MakeGenericType (ParamArray typeArguments As Type()) As Type
Public Overridable Function MakeGenericType (ParamArray typeArguments As Type()) As Type
Parametrar
- typeArguments
- Type[]
En matris med typer som ska ersättas med typparametrarna för den aktuella generiska typen.
Returer
En Type som representerar den konstruerade typen som bildas genom att ersätta elementen typeArguments i för typparametrarna för den aktuella generiska typen.
- Attribut
Undantag
Den aktuella typen representerar inte en allmän typdefinition. Det vill: IsGenericTypeDefinition returnerar false.
Antalet element i typeArguments är inte detsamma som antalet typparametrar i den aktuella generiska typdefinitionen.
-eller-
Alla element i typeArguments uppfyller inte de begränsningar som angetts för motsvarande typparameter för den aktuella generiska typen.
-eller-
typeArguments innehåller ett element som är en pekartyp (IsPointer returnerar true), en by-ref-typ (IsByRef returnerar true) eller Void.
Den anropade metoden stöds inte i basklassen. Härledda klasser måste tillhandahålla en implementering.
Exempel
I följande exempel används MakeGenericType metoden för att skapa en konstruerad typ från den generiska typdefinitionen Dictionary<TKey,TValue> för typen. Den konstruerade typen representerar ett Dictionary<TKey,TValue> objekt Test med strängnycklar.
using System;
using System.Reflection;
using System.Collections.Generic;
public class Test
{
public static void Main()
{
Console.WriteLine("\r\n--- Create a constructed type from the generic Dictionary type.");
// Create a type object representing the generic Dictionary
// type, by omitting the type arguments (but keeping the
// comma that separates them, so the compiler can infer the
// number of type parameters).
Type generic = typeof(Dictionary<,>);
DisplayTypeInfo(generic);
// Create an array of types to substitute for the type
// parameters of Dictionary. The key is of type string, and
// the type to be contained in the Dictionary is Test.
Type[] typeArgs = { typeof(string), typeof(Test) };
// Create a Type object representing the constructed generic
// type.
Type constructed = generic.MakeGenericType(typeArgs);
DisplayTypeInfo(constructed);
// Compare the type objects obtained above to type objects
// obtained using typeof() and GetGenericTypeDefinition().
Console.WriteLine("\r\n--- Compare types obtained by different methods:");
Type t = typeof(Dictionary<String, Test>);
Console.WriteLine("\tAre the constructed types equal? {0}", t == constructed);
Console.WriteLine("\tAre the generic types equal? {0}",
t.GetGenericTypeDefinition() == generic);
}
private static void DisplayTypeInfo(Type t)
{
Console.WriteLine("\r\n{0}", t);
Console.WriteLine("\tIs this a generic type definition? {0}",
t.IsGenericTypeDefinition);
Console.WriteLine("\tIs it a generic type? {0}",
t.IsGenericType);
Type[] typeArguments = t.GetGenericArguments();
Console.WriteLine("\tList type arguments ({0}):", typeArguments.Length);
foreach (Type tParam in typeArguments)
{
Console.WriteLine("\t\t{0}", tParam);
}
}
}
/* This example produces the following output:
--- Create a constructed type from the generic Dictionary type.
System.Collections.Generic.Dictionary`2[TKey,TValue]
Is this a generic type definition? True
Is it a generic type? True
List type arguments (2):
TKey
TValue
System.Collections.Generic.Dictionary`2[System.String, Test]
Is this a generic type definition? False
Is it a generic type? True
List type arguments (2):
System.String
Test
--- Compare types obtained by different methods:
Are the constructed types equal? True
Are the generic types equal? True
*/
open System
open System.Collections.Generic
type Test() = class end
let displayTypeInfo (t: Type) =
printfn $"\r\n{t}"
printfn $"\tIs this a generic type definition? {t.IsGenericTypeDefinition}"
printfn $"\tIs it a generic type? {t.IsGenericType}"
let typeArguments = t.GetGenericArguments()
printfn $"\tList type arguments ({typeArguments.Length}):"
for tParam in typeArguments do
printfn $"\t\t{tParam}"
printfn "\r\n--- Create a constructed type from the generic Dictionary type."
// Create a type object representing the generic Dictionary
// type, by calling .GetGenericTypeDefinition().
let generic = typeof<Dictionary<_,_>>.GetGenericTypeDefinition()
displayTypeInfo generic
// Create an array of types to substitute for the type
// parameters of Dictionary. The key is of type string, and
// the type to be contained in the Dictionary is Test.
let typeArgs = [| typeof<string>; typeof<Test> |]
// Create a Type object representing the constructed generic type.
let constructed = generic.MakeGenericType typeArgs
displayTypeInfo constructed
(* This example produces the following output:
--- Create a constructed type from the generic Dictionary type.
System.Collections.Generic.Dictionary`2[TKey,TValue]
Is this a generic type definition? True
Is it a generic type? True
List type arguments (2):
TKey
TValue
System.Collections.Generic.Dictionary`2[System.String, Test]
Is this a generic type definition? False
Is it a generic type? True
List type arguments (2):
System.String
Test
*)
Imports System.Reflection
Imports System.Collections.Generic
Public Class Test
Public Shared Sub Main()
Console.WriteLine(vbCrLf & "--- Create a constructed type from the generic Dictionary type.")
' Create a type object representing the generic Dictionary
' type, by omitting the type arguments (but keeping the
' comma that separates them, so the compiler can infer the
' number of type parameters).
Dim generic As Type = GetType(Dictionary(Of ,))
DisplayTypeInfo(generic)
' Create an array of types to substitute for the type
' parameters of Dictionary. The key is of type string, and
' the type to be contained in the Dictionary is Test.
Dim typeArgs() As Type = { GetType(String), GetType(Test) }
' Create a Type object representing the constructed generic
' type.
Dim constructed As Type = generic.MakeGenericType(typeArgs)
DisplayTypeInfo(constructed)
' Compare the type objects obtained above to type objects
' obtained using GetType() and GetGenericTypeDefinition().
Console.WriteLine(vbCrLf & "--- Compare types obtained by different methods:")
Dim t As Type = GetType(Dictionary(Of String, Test))
Console.WriteLine(vbTab & "Are the constructed types equal? " _
& (t Is constructed))
Console.WriteLine(vbTab & "Are the generic types equal? " _
& (t.GetGenericTypeDefinition() Is generic))
End Sub
Private Shared Sub DisplayTypeInfo(ByVal t As Type)
Console.WriteLine(vbCrLf & t.ToString())
Console.WriteLine(vbTab & "Is this a generic type definition? " _
& t.IsGenericTypeDefinition)
Console.WriteLine(vbTab & "Is it a generic type? " _
& t.IsGenericType)
Dim typeArguments() As Type = t.GetGenericArguments()
Console.WriteLine(vbTab & "List type arguments ({0}):", _
typeArguments.Length)
For Each tParam As Type In typeArguments
Console.WriteLine(vbTab & vbTab & tParam.ToString())
Next
End Sub
End Class
' This example produces the following output:
'
'--- Create a constructed type from the generic Dictionary type.
'
'System.Collections.Generic.Dictionary'2[TKey,TValue]
' Is this a generic type definition? True
' Is it a generic type? True
' List type arguments (2):
' TKey
' TValue
'
'System.Collections.Generic.Dictionary`2[System.String,Test]
' Is this a generic type definition? False
' Is it a generic type? True
' List type arguments (2):
' System.String
' Test
'
'--- Compare types obtained by different methods:
' Are the constructed types equal? True
' Are the generic types equal? True
Kommentarer
Mer information om det här API:et finns i Kompletterande API-kommentarer för Type.MakeGenericType.