Type.HasElementType Eigenschaft

Definition

Namespace:

System

Assemblys:

netstandard.dll, System.Runtime.dll

Quelle:

Type.cs

Ruft einen Wert ab, der angibt, ob der aktuelle Type Typ einschließt oder auf einen anderen Typ verweist; d. h., ob es sich bei dem aktuellen Type Umschlag um ein Array, einen Zeiger oder um einen Verweis handelt.

public:
 property bool HasElementType { bool get(); };

public bool HasElementType { get; }

member this.HasElementType : bool

Public ReadOnly Property HasElementType As Boolean

Eigenschaftswert

Boolean

true wenn es sich Type um ein Array, einen Zeiger oder um einen Verweis handelt, andernfalls false.

Beispiele

Das folgende Beispiel gibt zurück true oder false hängt davon ab, ob es sich bei dem Objekt um ein Array, einen Bezugstyp oder einen Zeiger handelt.

// This code must be compiled with the /unsafe switch:
//   csc /unsafe source.cs
using System;
using System.Reflection;

public class Example
{
    // This method is for demonstration purposes.
    unsafe public void Test(ref int x, out int y, int* z)
    {
        *z = x = y = 0;
    }

    public static void Main()
    {
        // All of the following display 'True'.

        // Define an array, get its type, and display HasElementType.
        int[] nums = {1, 1, 2, 3, 5, 8, 13};
        Type t = nums.GetType();
        Console.WriteLine("HasElementType is '{0}' for array types.", t.HasElementType);

        // Test an array type without defining an array.
        t = typeof(Example[]);
        Console.WriteLine("HasElementType is '{0}' for array types.", t.HasElementType);

        // When you use Reflection Emit to emit dynamic methods and
        // assemblies, you can create array types using MakeArrayType.
        // The following creates the type 'array of Example'.
        t = typeof(Example).MakeArrayType();
        Console.WriteLine("HasElementType is '{0}' for array types.", t.HasElementType);

        // When you reflect over methods, HasElementType is true for
        // ref, out, and pointer parameter types. The following
        // gets the Test method, defined above, and examines its
        // parameters.
        MethodInfo mi = typeof(Example).GetMethod("Test");
        ParameterInfo[] parms = mi.GetParameters();
        t = parms[0].ParameterType;
        Console.WriteLine("HasElementType is '{0}' for ref parameter types.", t.HasElementType);
        t = parms[1].ParameterType;
        Console.WriteLine("HasElementType is '{0}' for out parameter types.", t.HasElementType);
        t = parms[2].ParameterType;
        Console.WriteLine("HasElementType is '{0}' for pointer parameter types.", t.HasElementType);

        // When you use Reflection Emit to emit dynamic methods and
        // assemblies, you can create pointer and ByRef types to use
        // when you define method parameters.
        t = typeof(Example).MakePointerType();
        Console.WriteLine("HasElementType is '{0}' for pointer types.", t.HasElementType);
        t = typeof(Example).MakeByRefType();
        Console.WriteLine("HasElementType is '{0}' for ByRef types.", t.HasElementType);
    }
}

#nowarn "9"
open FSharp.NativeInterop

type Example() =
    // This method is for demonstration purposes.
    member _.Test(x: int byref, y: int outref, z: int nativeptr) =
        x <- 0
        y <- 0
        NativePtr.write z 0

// All of the following display 'True'.

do
    // Define an array, get its type, and display HasElementType.
    let nums = [| 1; 1; 2; 3; 5; 8; 13 |]
    let t = nums.GetType()
    printfn $"HasElementType is '{t.HasElementType}' for array types."

    // Test an array type without defining an array.
    let t = typeof<Example[]>
    printfn $"HasElementType is '{t.HasElementType}' for array types."

    // When you use Reflection Emit to emit dynamic methods and
    // assemblies, you can create array types using MakeArrayType.
    // The following creates the type 'array of Example'.
    let t = typeof<Example>.MakeArrayType()
    printfn $"HasElementType is '{t.HasElementType}' for array types."

    // When you reflect over methods, HasElementType is true for
    // byref, outref, and pointer parameter types. The following
    // gets the Test method, defined above, and examines its
    // parameters.
    let mi = typeof<Example>.GetMethod "Test"
    let parms = mi.GetParameters()
    let t = parms[0].ParameterType
    printfn $"HasElementType is '{t.HasElementType}' for ref parameter types."
    let t = parms[1].ParameterType
    printfn $"HasElementType is '{t.HasElementType}' for out parameter types."
    let t = parms[2].ParameterType
    printfn $"HasElementType is '{t.HasElementType}' for pointer parameter types."

    // When you use Reflection Emit to emit dynamic methods and
    // assemblies, you can create pointer and ByRef types to use
    // when you define method parameters.
    let t = typeof<Example>.MakePointerType()
    printfn $"HasElementType is '{t.HasElementType}' for pointer types."
    let t = typeof<Example>.MakeByRefType()
    printfn $"HasElementType is '{t.HasElementType}' for ByRef types."

Imports System.Reflection
Imports System.Runtime.InteropServices

Public Class Example

    ' This method is for demonstration purposes.
    Public Shared Sub Test(ByRef x As Integer, <Out> ByRef y As Integer)
    End Sub

    Public Shared Sub Main()
        ' All of the following display 'True'.

        ' Define an array, get its type, and display HasElementType. 
        Dim nums() As Integer = {1, 1, 2, 3, 5, 8, 13}
        Dim t As Type = nums.GetType()
        Console.WriteLine("HasElementType is '{0}' for array types.", t.HasElementType)

        ' Test an array type without defining an array.
        t = GetType(Example())
        Console.WriteLine("HasElementType is '{0}' for array types.", t.HasElementType)

        ' When you use Reflection Emit to emit dynamic methods and
        ' assemblies, you can create array types using MakeArrayType.
        ' The following creates the type 'array of Example'.
        t = GetType(Example).MakeArrayType()
        Console.WriteLine("HasElementType is '{0}' for array types.", t.HasElementType)

        ' When you reflect over methods, HasElementType is true for
        ' ref, out, and pointer parameter types. The following 
        ' gets the Test method, defined above, and examines its
        ' parameters.
        Dim mi As MethodInfo = GetType(Example).GetMethod("Test")
        Dim parms() As ParameterInfo = mi.GetParameters()
        t = parms(0).ParameterType
        Console.WriteLine("HasElementType is '{0}' for ref parameter types.", t.HasElementType)
        t = parms(1).ParameterType
        Console.WriteLine("HasElementType is '{0}' for <Out> parameter types.", t.HasElementType)

        ' When you use Reflection Emit to emit dynamic methods and
        ' assemblies, you can create pointer and ByRef types to use
        ' when you define method parameters.
        t = GetType(Example).MakePointerType()
        Console.WriteLine("HasElementType is '{0}' for pointer types.", t.HasElementType)
        t = GetType(Example).MakeByRefType()
        Console.WriteLine("HasElementType is '{0}' for ByRef types.", t.HasElementType)
    End Sub 

End Class

Hinweise

Beispiel: Type.GetType("Int32[]"). HasElementType gibt zurück true, aber Type.GetType("Int32"). HasElementType gibt zurück false. HasElementType gibt auch für "Int32*" und "Int32&" zurück true .

Wenn der aktuelle Typ einen generischen Typ oder einen Typparameter in der Definition eines generischen Typs oder einer generischen Type Methode darstellt, gibt diese Eigenschaft immer zurück false.

Weitere Informationen

• HasElementTypeImpl()
• IsArray
• IsPointer
• IsByRef
• GetElementType()
• GetType()