IntPtr Struct

Definizione

public value class IntPtr

public value class IntPtr : IComparable, IComparable<IntPtr>, IEquatable<IntPtr>, IFormattable, System::Runtime::Serialization::ISerializable

public value class IntPtr : IComparable, IComparable<IntPtr>, IEquatable<IntPtr>, ISpanFormattable, System::Runtime::Serialization::ISerializable

public value class IntPtr : IComparable<IntPtr>, IEquatable<IntPtr>, IParsable<IntPtr>, ISpanParsable<IntPtr>, System::Numerics::IAdditionOperators<IntPtr, IntPtr, IntPtr>, System::Numerics::IAdditiveIdentity<IntPtr, IntPtr>, System::Numerics::IBinaryInteger<IntPtr>, System::Numerics::IBinaryNumber<IntPtr>, System::Numerics::IBitwiseOperators<IntPtr, IntPtr, IntPtr>, System::Numerics::IComparisonOperators<IntPtr, IntPtr, bool>, System::Numerics::IDecrementOperators<IntPtr>, System::Numerics::IDivisionOperators<IntPtr, IntPtr, IntPtr>, System::Numerics::IEqualityOperators<IntPtr, IntPtr, bool>, System::Numerics::IIncrementOperators<IntPtr>, System::Numerics::IMinMaxValue<IntPtr>, System::Numerics::IModulusOperators<IntPtr, IntPtr, IntPtr>, System::Numerics::IMultiplicativeIdentity<IntPtr, IntPtr>, System::Numerics::IMultiplyOperators<IntPtr, IntPtr, IntPtr>, System::Numerics::INumber<IntPtr>, System::Numerics::INumberBase<IntPtr>, System::Numerics::IShiftOperators<IntPtr, int, IntPtr>, System::Numerics::ISignedNumber<IntPtr>, System::Numerics::ISubtractionOperators<IntPtr, IntPtr, IntPtr>, System::Numerics::IUnaryNegationOperators<IntPtr, IntPtr>, System::Numerics::IUnaryPlusOperators<IntPtr, IntPtr>, System::Runtime::Serialization::ISerializable

public value class IntPtr : IComparable<IntPtr>, IEquatable<IntPtr>, IParsable<IntPtr>, ISpanParsable<IntPtr>, IUtf8SpanParsable<IntPtr>, System::Numerics::IAdditionOperators<IntPtr, IntPtr, IntPtr>, System::Numerics::IAdditiveIdentity<IntPtr, IntPtr>, System::Numerics::IBinaryInteger<IntPtr>, System::Numerics::IBinaryNumber<IntPtr>, System::Numerics::IBitwiseOperators<IntPtr, IntPtr, IntPtr>, System::Numerics::IComparisonOperators<IntPtr, IntPtr, bool>, System::Numerics::IDecrementOperators<IntPtr>, System::Numerics::IDivisionOperators<IntPtr, IntPtr, IntPtr>, System::Numerics::IEqualityOperators<IntPtr, IntPtr, bool>, System::Numerics::IIncrementOperators<IntPtr>, System::Numerics::IMinMaxValue<IntPtr>, System::Numerics::IModulusOperators<IntPtr, IntPtr, IntPtr>, System::Numerics::IMultiplicativeIdentity<IntPtr, IntPtr>, System::Numerics::IMultiplyOperators<IntPtr, IntPtr, IntPtr>, System::Numerics::INumber<IntPtr>, System::Numerics::INumberBase<IntPtr>, System::Numerics::IShiftOperators<IntPtr, int, IntPtr>, System::Numerics::ISignedNumber<IntPtr>, System::Numerics::ISubtractionOperators<IntPtr, IntPtr, IntPtr>, System::Numerics::IUnaryNegationOperators<IntPtr, IntPtr>, System::Numerics::IUnaryPlusOperators<IntPtr, IntPtr>, System::Runtime::Serialization::ISerializable

public value class IntPtr : IEquatable<IntPtr>, System::Runtime::Serialization::ISerializable

public value class IntPtr : System::Runtime::Serialization::ISerializable

public struct IntPtr

public readonly struct IntPtr : IComparable, IComparable<IntPtr>, IEquatable<IntPtr>, IFormattable, System.Runtime.Serialization.ISerializable

public readonly struct IntPtr : IComparable, IComparable<IntPtr>, IEquatable<IntPtr>, ISpanFormattable, System.Runtime.Serialization.ISerializable

public readonly struct IntPtr : IComparable<IntPtr>, IEquatable<IntPtr>, IParsable<IntPtr>, ISpanParsable<IntPtr>, System.Numerics.IAdditionOperators<IntPtr,IntPtr,IntPtr>, System.Numerics.IAdditiveIdentity<IntPtr,IntPtr>, System.Numerics.IBinaryInteger<IntPtr>, System.Numerics.IBinaryNumber<IntPtr>, System.Numerics.IBitwiseOperators<IntPtr,IntPtr,IntPtr>, System.Numerics.IComparisonOperators<IntPtr,IntPtr,bool>, System.Numerics.IDecrementOperators<IntPtr>, System.Numerics.IDivisionOperators<IntPtr,IntPtr,IntPtr>, System.Numerics.IEqualityOperators<IntPtr,IntPtr,bool>, System.Numerics.IIncrementOperators<IntPtr>, System.Numerics.IMinMaxValue<IntPtr>, System.Numerics.IModulusOperators<IntPtr,IntPtr,IntPtr>, System.Numerics.IMultiplicativeIdentity<IntPtr,IntPtr>, System.Numerics.IMultiplyOperators<IntPtr,IntPtr,IntPtr>, System.Numerics.INumber<IntPtr>, System.Numerics.INumberBase<IntPtr>, System.Numerics.IShiftOperators<IntPtr,int,IntPtr>, System.Numerics.ISignedNumber<IntPtr>, System.Numerics.ISubtractionOperators<IntPtr,IntPtr,IntPtr>, System.Numerics.IUnaryNegationOperators<IntPtr,IntPtr>, System.Numerics.IUnaryPlusOperators<IntPtr,IntPtr>, System.Runtime.Serialization.ISerializable

public readonly struct IntPtr : IComparable<IntPtr>, IEquatable<IntPtr>, IParsable<IntPtr>, ISpanParsable<IntPtr>, IUtf8SpanParsable<IntPtr>, System.Numerics.IAdditionOperators<IntPtr,IntPtr,IntPtr>, System.Numerics.IAdditiveIdentity<IntPtr,IntPtr>, System.Numerics.IBinaryInteger<IntPtr>, System.Numerics.IBinaryNumber<IntPtr>, System.Numerics.IBitwiseOperators<IntPtr,IntPtr,IntPtr>, System.Numerics.IComparisonOperators<IntPtr,IntPtr,bool>, System.Numerics.IDecrementOperators<IntPtr>, System.Numerics.IDivisionOperators<IntPtr,IntPtr,IntPtr>, System.Numerics.IEqualityOperators<IntPtr,IntPtr,bool>, System.Numerics.IIncrementOperators<IntPtr>, System.Numerics.IMinMaxValue<IntPtr>, System.Numerics.IModulusOperators<IntPtr,IntPtr,IntPtr>, System.Numerics.IMultiplicativeIdentity<IntPtr,IntPtr>, System.Numerics.IMultiplyOperators<IntPtr,IntPtr,IntPtr>, System.Numerics.INumber<IntPtr>, System.Numerics.INumberBase<IntPtr>, System.Numerics.IShiftOperators<IntPtr,int,IntPtr>, System.Numerics.ISignedNumber<IntPtr>, System.Numerics.ISubtractionOperators<IntPtr,IntPtr,IntPtr>, System.Numerics.IUnaryNegationOperators<IntPtr,IntPtr>, System.Numerics.IUnaryPlusOperators<IntPtr,IntPtr>, System.Runtime.Serialization.ISerializable

public struct IntPtr : IEquatable<IntPtr>, System.Runtime.Serialization.ISerializable

public readonly struct IntPtr : IEquatable<IntPtr>, System.Runtime.Serialization.ISerializable

[System.Serializable]
public struct IntPtr : System.Runtime.Serialization.ISerializable

[System.Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public struct IntPtr : System.Runtime.Serialization.ISerializable

public struct IntPtr : System.Runtime.Serialization.ISerializable

type nativeint = struct

type nativeint = struct
    interface IFormattable
    interface ISerializable

type nativeint = struct
    interface ISpanFormattable
    interface IFormattable
    interface ISerializable

type nativeint = struct
    interface IFormattable
    interface IParsable<nativeint>
    interface ISpanFormattable
    interface ISpanParsable<nativeint>
    interface IAdditionOperators<nativeint, nativeint, nativeint>
    interface IAdditiveIdentity<nativeint, nativeint>
    interface IBinaryInteger<nativeint>
    interface IBinaryNumber<nativeint>
    interface IBitwiseOperators<nativeint, nativeint, nativeint>
    interface IComparisonOperators<nativeint, nativeint, bool>
    interface IEqualityOperators<nativeint, nativeint, bool>
    interface IDecrementOperators<nativeint>
    interface IDivisionOperators<nativeint, nativeint, nativeint>
    interface IIncrementOperators<nativeint>
    interface IModulusOperators<nativeint, nativeint, nativeint>
    interface IMultiplicativeIdentity<nativeint, nativeint>
    interface IMultiplyOperators<nativeint, nativeint, nativeint>
    interface INumber<nativeint>
    interface INumberBase<nativeint>
    interface ISubtractionOperators<nativeint, nativeint, nativeint>
    interface IUnaryNegationOperators<nativeint, nativeint>
    interface IUnaryPlusOperators<nativeint, nativeint>
    interface IShiftOperators<nativeint, int, nativeint>
    interface IMinMaxValue<nativeint>
    interface ISignedNumber<nativeint>
    interface ISerializable

type nativeint = struct
    interface IFormattable
    interface IParsable<nativeint>
    interface ISpanFormattable
    interface ISpanParsable<nativeint>
    interface IAdditionOperators<nativeint, nativeint, nativeint>
    interface IAdditiveIdentity<nativeint, nativeint>
    interface IBinaryInteger<nativeint>
    interface IBinaryNumber<nativeint>
    interface IBitwiseOperators<nativeint, nativeint, nativeint>
    interface IComparisonOperators<nativeint, nativeint, bool>
    interface IEqualityOperators<nativeint, nativeint, bool>
    interface IDecrementOperators<nativeint>
    interface IDivisionOperators<nativeint, nativeint, nativeint>
    interface IIncrementOperators<nativeint>
    interface IModulusOperators<nativeint, nativeint, nativeint>
    interface IMultiplicativeIdentity<nativeint, nativeint>
    interface IMultiplyOperators<nativeint, nativeint, nativeint>
    interface INumber<nativeint>
    interface INumberBase<nativeint>
    interface ISubtractionOperators<nativeint, nativeint, nativeint>
    interface IUnaryNegationOperators<nativeint, nativeint>
    interface IUnaryPlusOperators<nativeint, nativeint>
    interface IUtf8SpanFormattable
    interface IUtf8SpanParsable<nativeint>
    interface IShiftOperators<nativeint, int, nativeint>
    interface IMinMaxValue<nativeint>
    interface ISignedNumber<nativeint>
    interface ISerializable

type nativeint = struct
    interface IFormattable
    interface IParsable<nativeint>
    interface ISpanFormattable
    interface ISpanParsable<nativeint>
    interface IUtf8SpanFormattable
    interface IUtf8SpanParsable<nativeint>
    interface IAdditionOperators<nativeint, nativeint, nativeint>
    interface IAdditiveIdentity<nativeint, nativeint>
    interface IBinaryInteger<nativeint>
    interface IBinaryNumber<nativeint>
    interface IBitwiseOperators<nativeint, nativeint, nativeint>
    interface IComparisonOperators<nativeint, nativeint, bool>
    interface IEqualityOperators<nativeint, nativeint, bool>
    interface IDecrementOperators<nativeint>
    interface IDivisionOperators<nativeint, nativeint, nativeint>
    interface IIncrementOperators<nativeint>
    interface IModulusOperators<nativeint, nativeint, nativeint>
    interface IMultiplicativeIdentity<nativeint, nativeint>
    interface IMultiplyOperators<nativeint, nativeint, nativeint>
    interface INumber<nativeint>
    interface INumberBase<nativeint>
    interface ISubtractionOperators<nativeint, nativeint, nativeint>
    interface IUnaryNegationOperators<nativeint, nativeint>
    interface IUnaryPlusOperators<nativeint, nativeint>
    interface IShiftOperators<nativeint, int, nativeint>
    interface IMinMaxValue<nativeint>
    interface ISignedNumber<nativeint>
    interface ISerializable

type nativeint = struct
    interface ISerializable

[<System.Serializable>]
type nativeint = struct
    interface ISerializable

[<System.Serializable>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type nativeint = struct
    interface ISerializable

Public Structure IntPtr

Public Structure IntPtr
Implements IComparable, IComparable(Of IntPtr), IEquatable(Of IntPtr), IFormattable, ISerializable

Public Structure IntPtr
Implements IComparable, IComparable(Of IntPtr), IEquatable(Of IntPtr), ISerializable, ISpanFormattable

Public Structure IntPtr
Implements IAdditionOperators(Of IntPtr, IntPtr, IntPtr), IAdditiveIdentity(Of IntPtr, IntPtr), IBinaryInteger(Of IntPtr), IBinaryNumber(Of IntPtr), IBitwiseOperators(Of IntPtr, IntPtr, IntPtr), IComparable(Of IntPtr), IComparisonOperators(Of IntPtr, IntPtr, Boolean), IDecrementOperators(Of IntPtr), IDivisionOperators(Of IntPtr, IntPtr, IntPtr), IEqualityOperators(Of IntPtr, IntPtr, Boolean), IEquatable(Of IntPtr), IIncrementOperators(Of IntPtr), IMinMaxValue(Of IntPtr), IModulusOperators(Of IntPtr, IntPtr, IntPtr), IMultiplicativeIdentity(Of IntPtr, IntPtr), IMultiplyOperators(Of IntPtr, IntPtr, IntPtr), INumber(Of IntPtr), INumberBase(Of IntPtr), IParsable(Of IntPtr), ISerializable, IShiftOperators(Of IntPtr, Integer, IntPtr), ISignedNumber(Of IntPtr), ISpanParsable(Of IntPtr), ISubtractionOperators(Of IntPtr, IntPtr, IntPtr), IUnaryNegationOperators(Of IntPtr, IntPtr), IUnaryPlusOperators(Of IntPtr, IntPtr)

Public Structure IntPtr
Implements IAdditionOperators(Of IntPtr, IntPtr, IntPtr), IAdditiveIdentity(Of IntPtr, IntPtr), IBinaryInteger(Of IntPtr), IBinaryNumber(Of IntPtr), IBitwiseOperators(Of IntPtr, IntPtr, IntPtr), IComparable(Of IntPtr), IComparisonOperators(Of IntPtr, IntPtr, Boolean), IDecrementOperators(Of IntPtr), IDivisionOperators(Of IntPtr, IntPtr, IntPtr), IEqualityOperators(Of IntPtr, IntPtr, Boolean), IEquatable(Of IntPtr), IIncrementOperators(Of IntPtr), IMinMaxValue(Of IntPtr), IModulusOperators(Of IntPtr, IntPtr, IntPtr), IMultiplicativeIdentity(Of IntPtr, IntPtr), IMultiplyOperators(Of IntPtr, IntPtr, IntPtr), INumber(Of IntPtr), INumberBase(Of IntPtr), IParsable(Of IntPtr), ISerializable, IShiftOperators(Of IntPtr, Integer, IntPtr), ISignedNumber(Of IntPtr), ISpanParsable(Of IntPtr), ISubtractionOperators(Of IntPtr, IntPtr, IntPtr), IUnaryNegationOperators(Of IntPtr, IntPtr), IUnaryPlusOperators(Of IntPtr, IntPtr), IUtf8SpanParsable(Of IntPtr)

Public Structure IntPtr
Implements IEquatable(Of IntPtr), ISerializable

Public Structure IntPtr
Implements ISerializable

Ereditarietà

Object

ValueType

IntPtr

Attributi

SerializableAttribute ComVisibleAttribute

Implementazioni

IComparable IComparable<IntPtr> IEquatable<IntPtr> IFormattable ISerializable ISpanFormattable IComparable<TSelf> IEquatable<TSelf> IParsable<IntPtr> IParsable<TSelf> ISpanParsable<IntPtr> ISpanParsable<TSelf> IAdditionOperators<IntPtr,IntPtr,IntPtr> IAdditionOperators<TSelf,TSelf,TSelf> IAdditiveIdentity<IntPtr,IntPtr> IAdditiveIdentity<TSelf,TSelf> IBinaryInteger<IntPtr> IBinaryNumber<IntPtr> IBinaryNumber<TSelf> IBitwiseOperators<IntPtr,IntPtr,IntPtr> IBitwiseOperators<TSelf,TSelf,TSelf> IComparisonOperators<IntPtr,IntPtr,Boolean> IComparisonOperators<TSelf,TSelf,Boolean> IDecrementOperators<IntPtr> IDecrementOperators<TSelf> IDivisionOperators<IntPtr,IntPtr,IntPtr> IDivisionOperators<TSelf,TSelf,TSelf> IEqualityOperators<IntPtr,IntPtr,Boolean> IEqualityOperators<TSelf,TOther,TResult> IEqualityOperators<TSelf,TSelf,Boolean> IIncrementOperators<IntPtr> IIncrementOperators<TSelf> IMinMaxValue<IntPtr> IModulusOperators<IntPtr,IntPtr,IntPtr> IModulusOperators<TSelf,TSelf,TSelf> IMultiplicativeIdentity<IntPtr,IntPtr> IMultiplicativeIdentity<TSelf,TSelf> IMultiplyOperators<IntPtr,IntPtr,IntPtr> IMultiplyOperators<TSelf,TSelf,TSelf> INumber<IntPtr> INumber<TSelf> INumberBase<IntPtr> INumberBase<TSelf> IShiftOperators<IntPtr,Int32,IntPtr> IShiftOperators<TSelf,Int32,TSelf> ISignedNumber<IntPtr> ISubtractionOperators<IntPtr,IntPtr,IntPtr> ISubtractionOperators<TSelf,TSelf,TSelf> IUnaryNegationOperators<IntPtr,IntPtr> IUnaryNegationOperators<TSelf,TSelf> IUnaryPlusOperators<IntPtr,IntPtr> IUnaryPlusOperators<TSelf,TSelf> IUtf8SpanFormattable IUtf8SpanParsable<IntPtr> IUtf8SpanParsable<TSelf>

Esempio

Nell'esempio seguente vengono usati puntatori gestiti per invertire i caratteri in una matrice. Dopo aver inizializzato un oggetto String e ne ottiene la lunghezza, esegue le operazioni seguenti:

1. Chiama il metodo Marshal.StringToHGlobalAnsi per copiare la stringa Unicode nella memoria non gestita come carattere ANSI (a un byte). Il metodo restituisce un oggetto IntPtr che punta all'inizio della stringa non gestita. L'esempio di Visual Basic usa direttamente questo puntatore; negli esempi C++, F# e C# viene eseguito il cast a un puntatore a un byte.

2. Chiama il metodo Marshal.AllocHGlobal per allocare lo stesso numero di byte occupato dalla stringa non gestita. Il metodo restituisce un oggetto IntPtr che punta all'inizio del blocco di memoria non gestito. L'esempio di Visual Basic usa direttamente questo puntatore; negli esempi C++, F# e C# viene eseguito il cast a un puntatore a un byte.

3. Nell'esempio di Visual Basic viene definita una variabile denominata offset uguale alla lunghezza della stringa ANSI. Viene usato per determinare l'offset in memoria non gestita in cui viene copiato il carattere successivo nella stringa ANSI. Poiché il valore iniziale è la lunghezza della stringa, l'operazione di copia copia copia un carattere dall'inizio della stringa alla fine del blocco di memoria.

   Gli esempi C#, F# e C++ chiamano il metodo ToPointer per ottenere un puntatore non gestito all'indirizzo iniziale della stringa e al blocco di memoria non gestito e aggiungono uno minore della lunghezza della stringa all'indirizzo iniziale della stringa ANSI. Poiché il puntatore stringa non gestito punta ora alla fine della stringa, l'operazione di copia copia copiarà un carattere dalla fine della stringa all'inizio del blocco di memoria.

4. Usa un ciclo per copiare ogni carattere dalla stringa al blocco di memoria non gestito.

   Nell'esempio di Visual Basic viene chiamato il metodo Marshal.ReadByte(IntPtr, Int32) per leggere il byte (o un carattere a un byte) in corrispondenza di un offset specificato dal puntatore gestito alla stringa ANSI. L'offset viene incrementato con ogni iterazione del ciclo. Chiama quindi il metodo Marshal.WriteByte(IntPtr, Int32, Byte) per scrivere il byte nell'indirizzo di memoria definito dall'indirizzo iniziale del blocco di memoria non gestito più offset. Quindi decrementa offset.

   Gli esempi C#, F# e C++ eseguono l'operazione di copia, quindi decrementare il puntatore all'indirizzo della posizione successiva nella stringa ANSI non gestita e incrementare il puntatore all'indirizzo successivo nel blocco non gestito.

5. Tutti gli esempi chiamano il Marshal.PtrToStringAnsi per convertire il blocco di memoria non gestito contenente la stringa ANSI copiata in un oggetto String Unicode gestito.

6. Dopo aver visualizzato le stringhe originali e invertite, tutti gli esempi chiamano il metodo FreeHGlobal per liberare la memoria allocata per la stringa ANSI non gestita e il blocco di memoria non gestito.

using namespace System;
using namespace System::Runtime::InteropServices;

class NotTooSafeStringReverse
{
public:
    static void Main()
    {
        String^ stringA = "I seem to be turned around!";
        int copylen = stringA->Length;

        // Allocate HGlobal memory for source and destination strings
        IntPtr sptr = Marshal::StringToHGlobalAnsi(stringA);
        IntPtr dptr = Marshal::AllocHGlobal(copylen + 1);

        char *src = (char *)sptr.ToPointer();
        char *dst = (char *)dptr.ToPointer();

        if (copylen > 0)
        {
            // set the source pointer to the end of the string
            // to do a reverse copy.
            src += copylen - 1;

            while (copylen-- > 0)
            {
                *dst++ = *src--;
            }
            *dst = 0;
        }
        String^ stringB = Marshal::PtrToStringAnsi(dptr);

        Console::WriteLine("Original:\n{0}\n", stringA);
        Console::WriteLine("Reversed:\n{0}", stringB);

        // Free HGlobal memory
        Marshal::FreeHGlobal(dptr);
        Marshal::FreeHGlobal(sptr);
    }
};

int main()
{
    NotTooSafeStringReverse::Main();
}

// The progam has the following output:
//
// Original:
// I seem to be turned around!
//
// Reversed:
// !dnuora denrut eb ot mees I

using System;
using System.Runtime.InteropServices;

class NotTooSafeStringReverse
{
    static public void Main()
    {
        string stringA = "I seem to be turned around!";
        int copylen = stringA.Length;

        // Allocate HGlobal memory for source and destination strings
        IntPtr sptr = Marshal.StringToHGlobalAnsi(stringA);
        IntPtr dptr = Marshal.AllocHGlobal(copylen + 1);

        // The unsafe section where byte pointers are used.
        unsafe
        {
            byte *src = (byte *)sptr.ToPointer();
            byte *dst = (byte *)dptr.ToPointer();

            if (copylen > 0)
            {
                // set the source pointer to the end of the string
                // to do a reverse copy.
                src += copylen - 1;

                while (copylen-- > 0)
                {
                    *dst++ = *src--;
                }
                *dst = 0;
            }
        }
        string stringB = Marshal.PtrToStringAnsi(dptr);

        Console.WriteLine("Original:\n{0}\n", stringA);
        Console.WriteLine("Reversed:\n{0}", stringB);

        // Free HGlobal memory
        Marshal.FreeHGlobal(dptr);
        Marshal.FreeHGlobal(sptr);
    }
}

// The progam has the following output:
//
// Original:
// I seem to be turned around!
//
// Reversed:
// !dnuora denrut eb ot mees I

#nowarn "9"
open System.Runtime.InteropServices
open FSharp.NativeInterop

[<EntryPoint>]
let main _ = 
    let stringA = "I seem to be turned around!"
    let mutable copylen = stringA.Length

    // Allocate HGlobal memory for source and destination strings
    let sptr = Marshal.StringToHGlobalAnsi stringA
    let dptr = Marshal.AllocHGlobal(copylen + 1)

    let mutable src: byte nativeptr = sptr.ToPointer() |> NativePtr.ofVoidPtr
    let mutable dst: byte nativeptr = dptr.ToPointer() |> NativePtr.ofVoidPtr

    if copylen > 0 then
        // set the source pointer to the end of the string
        // to do a reverse copy.
        src <- 
            NativePtr.toNativeInt src + nativeint (copylen - 1) 
            |> NativePtr.ofNativeInt

        while copylen > 0 do
            copylen <- copylen - 1
            NativePtr.read src |> NativePtr.write dst
            dst <- NativePtr.toNativeInt dst + 1n |> NativePtr.ofNativeInt
            src <- NativePtr.toNativeInt src - 1n |> NativePtr.ofNativeInt
        NativePtr.write dst 0uy

    let stringB = Marshal.PtrToStringAnsi dptr

    printfn $"Original:\n{stringA}\n"
    printfn $"Reversed:\n{stringB}"

    // Free HGlobal memory
    Marshal.FreeHGlobal dptr
    Marshal.FreeHGlobal sptr
    0

// The progam has the following output:
//
// Original:
// I seem to be turned around!
//
// Reversed:
// !dnuora denrut eb ot mees I

Imports System.Runtime.InteropServices

Public Module Example
    Public Sub Main()
        Dim stringA As String = "I seem to be turned around!"
        Dim copylen As Integer = stringA.Length

        ' Allocate HGlobal memory for source and destination strings
        Dim sptr As IntPtr = Marshal.StringToHGlobalAnsi(stringA)
        Dim dptr As IntPtr = Marshal.AllocHGlobal(copylen)
        Dim offset As Integer = copylen - 1

         For ctr As Integer = 0 To copylen - 1
            Dim b As Byte = Marshal.ReadByte(sptr, ctr)
            Marshal.WriteByte(dptr, offset, b)
            offset -= 1
         Next

        Dim stringB As String = Marshal.PtrToStringAnsi(dptr)

        Console.WriteLine("Original:{1}{0}{1}", stringA, vbCrLf)
        Console.WriteLine("Reversed:{1}{0}{1}", stringB, vbCrLf)

        ' Free HGlobal memory
        Marshal.FreeHGlobal(dptr)
        Marshal.FreeHGlobal(sptr)
    End Sub
End Module
' The example displays the following output:
'       Original:
'       I seem to be turned around!
'
'       Reversed:
'       !dnuora denrut eb ot mees I

Commenti

Il tipo IntPtr è progettato per essere un numero intero la cui dimensione è uguale a un puntatore. Ovvero, un'istanza di questo tipo dovrebbe essere a 32 bit in un processo a 32 bit e 64 bit in un processo a 64 bit.

Il tipo IntPtr può essere usato da linguaggi che supportano puntatori e come mezzo comune per fare riferimento ai dati tra lingue che e non supportano i puntatori.

IntPtr oggetti possono essere usati anche per contenere handle. Ad esempio, le istanze di IntPtr vengono usate ampiamente nella classe System.IO.FileStream per contenere handle di file.

Questo tipo implementa l'ISerializable. In .NET 5 e versioni successive, questo tipo implementa anche le interfacce IFormattable. In .NET 7 e versioni successive, questo tipo implementa anche le interfacce IBinaryInteger<TSelf>, IMinMaxValue<TSelf>e ISignedNumber<TSelf>.

In C# a partire dalla versione 9.0 è possibile usare il tipo di nint predefinito per definire numeri interi di dimensioni native. Questo tipo è rappresentato dal tipo IntPtr internamente e fornisce operazioni e conversioni appropriate per i tipi integer. Per altre informazioni, vedere tipi nint e nuint.

In C# a partire dalla versione 11 e quando è destinata al runtime .NET 7 o versione successiva, nint è un alias per IntPtr nello stesso modo in cui int è un alias per Int32.

Costruttori

Campi

Proprietà

Metodi

Operatori

Implementazioni dell'interfaccia esplicita

Si applica a

Thread safety

Questo tipo è thread-safe.

Vedi anche

• UIntPtr