Type.IsGenericType 属性

参考

定义

命名空间:: System

程序集:: System.Runtime.dll

程序集:: mscorlib.dll

程序集:: netstandard.dll

Source:: Type.cs

Source:: Type.cs

Source:: Type.cs

重要

一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。

获取一个值，该值指示当前类型是否是泛型类型。

public:
 virtual property bool IsGenericType { bool get(); };

public virtual bool IsGenericType { get; }

member this.IsGenericType : bool

Public Overridable ReadOnly Property IsGenericType As Boolean

属性值

Boolean

true 如果当前类型是泛型类型，则为 ;否则为 false。

示例

下面的代码示例显示备注部分所述的类型的、IsGenericTypeDefinition、 IsGenericParameter和 ContainsGenericParameters 属性的值IsGenericType。有关属性值的说明，请参阅备注中随附的表。

using namespace System;
using namespace System::Reflection;

generic<typename T, typename U> public ref class Base {};

generic<typename T> public ref class G {};

generic<typename V> public ref class Derived : Base<String^, V>
{
public: 
    G<Derived<V>^>^ F;

    ref class Nested {};
};

void DisplayGenericType(Type^ t, String^ caption)
{
    Console::WriteLine("\n{0}", caption);
    Console::WriteLine("    Type: {0}", t);

    Console::WriteLine("\t            IsGenericType: {0}", 
        t->IsGenericType);
    Console::WriteLine("\t  IsGenericTypeDefinition: {0}", 
        t->IsGenericTypeDefinition);
    Console::WriteLine("\tContainsGenericParameters: {0}", 
        t->ContainsGenericParameters);
    Console::WriteLine("\t       IsGenericParameter: {0}", 
        t->IsGenericParameter);
}

void main()
{
    // Get the generic type definition for Derived, and the base
    // type for Derived.
    //
    Type^ tDerived = Derived::typeid;
    Type^ tDerivedBase = tDerived->BaseType;

    // Declare an array of Derived<int>, and get its type.
    //
    array<Derived<int>^>^ d = gcnew array<Derived<int>^>(0);
    Type^ tDerivedArray = d->GetType();

    // Get a generic type parameter, the type of a field, and a
    // type that is nested in Derived. Notice that in order to
    // get the nested type it is necessary to either (1) specify
    // the generic type definition Derived::typeid, as shown here,
    // or (2) specify a type parameter for Derived.
    //
    Type^ tT = Base::typeid->GetGenericArguments()[0];
    Type^ tF = tDerived->GetField("F")->FieldType;
    Type^ tNested = Derived::Nested::typeid;

    DisplayGenericType(tDerived, "generic<V> Derived");
    DisplayGenericType(tDerivedBase, "Base type of generic<V> Derived");
    DisplayGenericType(tDerivedArray, "Array of Derived<int>");
    DisplayGenericType(tT, "Type parameter T from generic<T> Base");
    DisplayGenericType(tF, "Field type, G<Derived<V>^>^");
    DisplayGenericType(tNested, "Nested type in generic<V> Derived");
}

/* This code example produces the following output:

generic<V> Derived
    Type: Derived`1[V]
                    IsGenericType: True
          IsGenericTypeDefinition: True
        ContainsGenericParameters: True
               IsGenericParameter: False

Base type of generic<V> Derived
    Type: Base`2[System.String,V]
                    IsGenericType: True
          IsGenericTypeDefinition: False
        ContainsGenericParameters: True
               IsGenericParameter: False

Array of Derived<int>
    Type: Derived`1[System.Int32][]
                    IsGenericType: False
          IsGenericTypeDefinition: False
        ContainsGenericParameters: False
               IsGenericParameter: False

Type parameter T from generic<T> Base
    Type: T
                    IsGenericType: False
          IsGenericTypeDefinition: False
        ContainsGenericParameters: True
               IsGenericParameter: True

Field type, G<Derived<V>^>^
    Type: G`1[Derived`1[V]]
                    IsGenericType: True
          IsGenericTypeDefinition: False
        ContainsGenericParameters: True
               IsGenericParameter: False

Nested type in generic<V> Derived
    Type: Derived`1+Nested[V]
                    IsGenericType: True
          IsGenericTypeDefinition: True
        ContainsGenericParameters: True
               IsGenericParameter: False
 */

using System;
using System.Reflection;

public class Base<T, U> {}

public class Derived<V> : Base<string, V>
{
    public G<Derived <V>> F;

    public class Nested {}
}

public class G<T> {}

class Example
{
    public static void Main()
    {
        // Get the generic type definition for Derived, and the base
        // type for Derived.
        //
        Type tDerived = typeof(Derived<>);
        Type tDerivedBase = tDerived.BaseType;

        // Declare an array of Derived<int>, and get its type.
        //
        Derived<int>[] d = new Derived<int>[0];
        Type tDerivedArray = d.GetType();

        // Get a generic type parameter, the type of a field, and a
        // type that is nested in Derived. Notice that in order to
        // get the nested type it is necessary to either (1) specify
        // the generic type definition Derived<>, as shown here,
        // or (2) specify a type parameter for Derived.
        //
        Type tT = typeof(Base<,>).GetGenericArguments()[0];
        Type tF = tDerived.GetField("F").FieldType;
        Type tNested = typeof(Derived<>.Nested);

        DisplayGenericType(tDerived, "Derived<V>");
        DisplayGenericType(tDerivedBase, "Base type of Derived<V>");
        DisplayGenericType(tDerivedArray, "Array of Derived<int>");
        DisplayGenericType(tT, "Type parameter T from Base<T>");
        DisplayGenericType(tF, "Field type, G<Derived<V>>");
        DisplayGenericType(tNested, "Nested type in Derived<V>");
    }

    public static void DisplayGenericType(Type t, string caption)
    {
        Console.WriteLine("\n{0}", caption);
        Console.WriteLine("    Type: {0}", t);

        Console.WriteLine("\t            IsGenericType: {0}", 
            t.IsGenericType);
        Console.WriteLine("\t  IsGenericTypeDefinition: {0}", 
            t.IsGenericTypeDefinition);
        Console.WriteLine("\tContainsGenericParameters: {0}", 
            t.ContainsGenericParameters);
        Console.WriteLine("\t       IsGenericParameter: {0}", 
            t.IsGenericParameter);
    }
}

/* This code example produces the following output:

Derived<V>
    Type: Derived`1[V]
                    IsGenericType: True
          IsGenericTypeDefinition: True
        ContainsGenericParameters: True
               IsGenericParameter: False

Base type of Derived<V>
    Type: Base`2[System.String,V]
                    IsGenericType: True
          IsGenericTypeDefinition: False
        ContainsGenericParameters: True
               IsGenericParameter: False

Array of Derived<int>
    Type: Derived`1[System.Int32][]
                    IsGenericType: False
          IsGenericTypeDefinition: False
        ContainsGenericParameters: False
               IsGenericParameter: False

Type parameter T from Base<T>
    Type: T
                    IsGenericType: False
          IsGenericTypeDefinition: False
        ContainsGenericParameters: True
               IsGenericParameter: True

Field type, G<Derived<V>>
    Type: G`1[Derived`1[V]]
                    IsGenericType: True
          IsGenericTypeDefinition: False
        ContainsGenericParameters: True
               IsGenericParameter: False

Nested type in Derived<V>
    Type: Derived`1+Nested[V]
                    IsGenericType: True
          IsGenericTypeDefinition: True
        ContainsGenericParameters: True
               IsGenericParameter: False
 */

open System

type Base<'T, 'U>() = class end

type G<'T>() = class end

type Derived<'V>() =
    inherit Base<string, 'V>()
    
    [<DefaultValue>]
    val mutable public F : G<Derived<'V>>

let displayGenericType (t: Type) caption =
    printfn $"\n{caption}"
    printfn $"    Type: {t}"

    printfn $"\t            IsGenericType: {t.IsGenericType}" 
    printfn $"\t  IsGenericTypeDefinition: {t.IsGenericTypeDefinition}" 
    printfn $"\tContainsGenericParameters: {t.ContainsGenericParameters}"
    printfn $"\t       IsGenericParameter: {t.IsGenericParameter}"

// Get the generic type definition for Derived, and the base
// type for Derived.
let tDerived = typeof<Derived<_>>.GetGenericTypeDefinition()
let tDerivedBase = tDerived.BaseType

// Declare an array of Derived<int>, and get its type.
let d = Array.zeroCreate<Derived<int>> 0
let tDerivedArray = d.GetType()

// Get a generic type parameter, the type of a field, and a
// type that is nested in Derived. Notice that in order to
// get the nested type it is necessary to either (1) specify
// the generic type definition Derived<>, as shown here,
// or (2) specify a type parameter for Derived.
let tT = typeof<Base<_,_>>.GetGenericTypeDefinition().GetGenericArguments()[0]
let tF = tDerived.GetField("F").FieldType

displayGenericType tDerived "Derived<V>"
displayGenericType tDerivedBase "Base type of Derived<V>"
displayGenericType tDerivedArray "Array of Derived<int>"
displayGenericType tT "Type parameter T from Base<T>"
displayGenericType tF "Field type, G<Derived<V>>"

(* This code example produces the following output:

Derived<V>
    Type: Derived`1[V]
                    IsGenericType: True
          IsGenericTypeDefinition: True
        ContainsGenericParameters: True
               IsGenericParameter: False

Base type of Derived<V>
    Type: Base`2[System.String,V]
                    IsGenericType: True
          IsGenericTypeDefinition: False
        ContainsGenericParameters: True
               IsGenericParameter: False

Array of Derived<int>
    Type: Derived`1[System.Int32][]
                    IsGenericType: False
          IsGenericTypeDefinition: False
        ContainsGenericParameters: False
               IsGenericParameter: False

Type parameter T from Base<T>
    Type: T
                    IsGenericType: False
          IsGenericTypeDefinition: False
        ContainsGenericParameters: True
               IsGenericParameter: True

Field type, G<Derived<V>>
    Type: G`1[Derived`1[V]]
                    IsGenericType: True
          IsGenericTypeDefinition: False
        ContainsGenericParameters: True
               IsGenericParameter: False
 *)

Imports System.Reflection

' 
Public Class Base(Of T, U)
End Class

Public Class Derived(Of V) 
    Inherits Base(Of String, V)

    Public F As G(Of Derived(Of V))

    Public Class Nested
    End Class
End Class

Public Class G(Of T)
End Class 

Module Example

    Sub Main

        ' Get the generic type definition for Derived, and the base
        ' type for Derived.
        '
        Dim tDerived As Type = GetType(Derived(Of ))
        Dim tDerivedBase As Type = tDerived.BaseType

        ' Declare an array of Derived(Of Integer), and get its type.
        '
        Dim d(0) As Derived(Of Integer)
        Dim tDerivedArray As Type = d.GetType()

        ' Get a generic type parameter, the type of a field, and a
        ' type that is nested in Derived. Notice that in order to
        ' get the nested type it is necessary to either (1) specify
        ' the generic type definition Derived(Of ), as shown here,
        ' or (2) specify a type parameter for Derived.
        '
        Dim tT As Type = GetType(Base(Of ,)).GetGenericArguments()(0)
        Dim tF As Type = tDerived.GetField("F").FieldType
        Dim tNested As Type = GetType(Derived(Of ).Nested)

        DisplayGenericType(tDerived, "Derived(Of V)")
        DisplayGenericType(tDerivedBase, "Base type of Derived(Of V)")
        DisplayGenericType(tDerivedArray, "Array of Derived(Of Integer)")
        DisplayGenericType(tT, "Type parameter T from Base(Of T)")
        DisplayGenericType(tF, "Field type, G(Of Derived(Of V))")
        DisplayGenericType(tNested, "Nested type in Derived(Of V)")

    End Sub

    Sub DisplayGenericType(ByVal t As Type, ByVal caption As String)

        Console.WriteLine(vbLf & caption)
        Console.WriteLine("    Type: {0}", t)

        Console.WriteLine(vbTab & "            IsGenericType: {0}", _
            t.IsGenericType)
        Console.WriteLine(vbTab & "  IsGenericTypeDefinition: {0}", _
            t.IsGenericTypeDefinition)
        Console.WriteLine(vbTab & "ContainsGenericParameters: {0}", _
            t.ContainsGenericParameters)
        Console.WriteLine(vbTab & "       IsGenericParameter: {0}", _
            t.IsGenericParameter)

    End Sub

End Module

' This code example produces the following output:
'
'Derived(Of V)
'    Type: Derived`1[V]
'                    IsGenericType: True
'          IsGenericTypeDefinition: True
'        ContainsGenericParameters: True
'               IsGenericParameter: False
'
'Base type of Derived(Of V)
'    Type: Base`2[System.String,V]
'                    IsGenericType: True
'          IsGenericTypeDefinition: False
'        ContainsGenericParameters: True
'               IsGenericParameter: False
'
'Array of Derived(Of Integer)
'    Type: Derived`1[System.Int32][]
'                    IsGenericType: False
'          IsGenericTypeDefinition: False
'        ContainsGenericParameters: False
'               IsGenericParameter: False
'
'Type parameter T from Base(Of T)
'    Type: T
'                    IsGenericType: False
'          IsGenericTypeDefinition: False
'        ContainsGenericParameters: True
'               IsGenericParameter: True
'
'Field type, G(Of Derived(Of V))
'    Type: G`1[Derived`1[V]]
'                    IsGenericType: True
'          IsGenericTypeDefinition: False
'        ContainsGenericParameters: True
'               IsGenericParameter: False
'
'Nested type in Derived(Of V)
'    Type: Derived`1+Nested[V]
'                    IsGenericType: True
'          IsGenericTypeDefinition: True
'        ContainsGenericParameters: True
'               IsGenericParameter: False

注解

IsGenericType使用属性确定对象是否Type表示泛型类型。 ContainsGenericParameters使用属性可以确定对象是表示打开的构造类型还是Type封闭的构造类型。

注意

如果直接类型不是泛型，则 IsGenericType 属性返回 false 。例如，其元素在 Visual Basic) 中属于 (A(Of Integer) 类型的A<int>数组本身不是泛型类型。

下表总结了泛型反射中使用的常用术语的固定条件。

术语	固定条件
Generic Type Definition — 泛型类型定义	IsGenericTypeDefinition 属性为 `true`。定义泛型类型。构造类型是通过对表示泛型类型定义的对象调用 MakeGenericType 方法 Type 并指定类型参数数组来创建的。 MakeGenericType 只能在泛型类型定义上调用。任何泛型类型定义都是泛型类型， IsGenericType (属性) `true` ，但反之则不成立。
Generic Type — 泛型类型	IsGenericType 属性为 `true`。可以是泛型类型定义、开放构造类型或封闭构造类型。请注意，元素类型为泛型的数组类型本身不是泛型类型。表示指向泛型类型的指针的对象也是如此 Type 。
open 构造类型	ContainsGenericParameters 属性为 `true`。示例包括具有未分配的类型参数的泛型类型、嵌套在泛型类型定义或开放式构造类型中的类型，或具有属性为的类型 ContainsGenericParameters 参数的 `true`泛型类型。无法创建开放式构造类型的实例。请注意，并非所有打开的构造类型都是泛型的。例如，其元素类型为泛型类型定义的数组不是泛型，指向打开的构造类型的指针不是泛型。
闭合构造类型	ContainsGenericParameters 属性为 `false`。以递归方式检查时，类型没有未分配的泛型参数。
Generic Type Parameter — 泛型类型参数	IsGenericParameter 属性为 `true`。 ContainsGenericParameters 属性为 `true`。在泛型类型定义中，为稍后将分配的类型占位符。
Generic Type Argument — 泛型类型变量	可以是任何类型，包括泛型类型参数。类型参数指定为在创建构造泛 Type 型类型时传递给 MakeGenericType 方法的对象数组。如果要创建生成的类型的实例，则 ContainsGenericParameters 所有类型参数的属性都必须 `false` 为。

下面的代码示例和表演示了其中一些术语和固定项。类 Derived 特别值得关注，因为它的基类型是一个构造类型，其类型参数列表中具有类型和类型参数的混合。

generic<typename T, typename U> public ref class Base {};

generic<typename T> public ref class G {};

generic<typename V> public ref class Derived : Base<String^, V>
{
public:
    G<Derived<V>^>^ F;

    ref class Nested {};
};

public class Base<T, U> {}

public class Derived<V> : Base<string, V>
{
    public G<Derived <V>> F;

    public class Nested {}
}

public class G<T> {}

type Base<'T, 'U>() = class end

type G<'T>() = class end

type Derived<'V>() =
    inherit Base<string, 'V>()
    
    [<DefaultValue>]
    val mutable public F : G<Derived<'V>>

Public Class Base(Of T, U)
End Class

Public Class Derived(Of V)
    Inherits Base(Of String, V)

    Public F As G(Of Derived(Of V))

    Public Class Nested
    End Class
End Class

Public Class G(Of T)
End Class

下表显示了使用和基于类 Base、 Derived和 G构建的示例。当 C++ 和 C# 代码相同时，仅显示一个条目。

示例	固定协定
`Derived(Of V)` `Derived<V>`	对于此类型： IsGenericType 为 `true`。 IsGenericTypeDefinition 为 `true`。 ContainsGenericParameters 为 `true`。
`Base(Of String, V)` `Base<String,V>` `Base<String^,V>`	对于此类型： IsGenericType 为 `true`。 IsGenericTypeDefinition 为 `false`。 ContainsGenericParameters 为 `true`。
`Dim d() As Derived(Of Integer)` `Derived<int>[] d;` `array<Derived<int>^>^ d;`	对于变量 `d`的类型： IsGenericType 是因为 `falsed` 是数组。 IsGenericTypeDefinition 为 `false`。 ContainsGenericParameters 为 `false`。
`T`、 `U`和 `V` (出现在任何位置)	IsGenericParameter 为 `true`。 IsGenericType 这是因为 `false` 无法将类型参数限制为泛型类型。 IsGenericTypeDefinition 为 `false`。 ContainsGenericParameters 是因为 `trueT`、 `U`和 `V` 本身是泛型类型参数。这并不表示有关稍后分配给它们的类型参数的任何内容。
字段的类型 `F`	IsGenericType 为 `true`。 IsGenericTypeDefinition 是因为 `false` 类型已分配给的类型 `G`参数。请注意，这等效于调用 MakeGenericType 方法。 ContainsGenericParameters 这是因为 `true` 字段 `F` 的类型具有一个类型参数，该类型参数是一个打开的构造类型。构造的类型是打开的，因为它的类型参数 (即 `Base` ，) 是泛型类型定义。这说明了属性的 IsGenericType 递归性质。
嵌套类 `Nested`	IsGenericType 为 `true`，尽管 `Nested` 类没有自己的泛型类型参数，因为它嵌套在泛型类型中。 IsGenericTypeDefinition 为 `true`。也就是说，可以调用 MakeGenericType 方法并提供封闭类型 `Derived`的类型参数。 ContainsGenericParameters 这是因为 `true` 封闭类型 `Derived`具有泛型类型参数。这说明了属性的 ContainsGenericParameters 递归性质。

适用于

Type.IsGenericType 属性

定义

属性值

示例

注解

适用于

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