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Marshal.ReadInt16 Method

Definition

Reads a 16-bit signed integer from unmanaged memory. Reading from unaligned memory locations is supported.

Overloads

ReadInt16(IntPtr)

Reads a 16-bit signed integer from unmanaged memory.

ReadInt16(IntPtr, Int32)

Reads a 16-bit signed integer at a given offset from unmanaged memory.

ReadInt16(Object, Int32)
Obsolete.

Reads a 16-bit signed integer at a given offset from unmanaged memory.

ReadInt16(IntPtr)

Source:
Marshal.cs
Source:
Marshal.cs
Source:
Marshal.cs

Reads a 16-bit signed integer from unmanaged memory.

public:
 static short ReadInt16(IntPtr ptr);
[System.Security.SecurityCritical]
public static short ReadInt16 (IntPtr ptr);
public static short ReadInt16 (IntPtr ptr);
[<System.Security.SecurityCritical>]
static member ReadInt16 : nativeint -> int16
static member ReadInt16 : nativeint -> int16
Public Shared Function ReadInt16 (ptr As IntPtr) As Short

Parameters

ptr
IntPtr

nativeint

The address in unmanaged memory from which to read.

Returns

The 16-bit signed integer read from unmanaged memory.

Attributes

Exceptions

ptr is not a recognized format.

-or-

ptr is null.

-or-

ptr is invalid.

Examples

The following example demonstrates how to read and write to an unmanaged array using the ReadInt16 and WriteInt16 methods.

static void ReadWriteInt16()
{
    // Allocate unmanaged memory. 
    int elementSize = 2;
    IntPtr unmanagedArray = Marshal.AllocHGlobal(10 * elementSize);

    // Set the 10 elements of the C-style unmanagedArray
    for (int i = 0; i < 10; i++)
    {
        Marshal.WriteInt16(unmanagedArray, i * elementSize, ((Int16)(i + 1)));
    }
    Console.WriteLine("Unmanaged memory written.");

    Console.WriteLine("Reading unmanaged memory:");
    // Print the 10 elements of the C-style unmanagedArray
    for (int i = 0; i < 10; i++)
    {
        Console.WriteLine(Marshal.ReadInt16(unmanagedArray, i * elementSize));
    }

    Marshal.FreeHGlobal(unmanagedArray);

    Console.WriteLine("Done. Press Enter to continue.");
    Console.ReadLine();
}
Sub ReadWriteInt16()
    ' Allocate unmanaged memory. 
    Dim elementSize As Integer = 2
    Dim unmanagedArray As IntPtr = Marshal.AllocHGlobal(10 * elementSize)

    ' Set the 10 elements of the C-style unmanagedArray
    For i As Integer = 0 To 9
        Marshal.WriteInt16(unmanagedArray, i * elementSize, CType(i + 1, Int16))
    Next i
    Console.WriteLine("Unmanaged memory written.")

    Console.WriteLine("Reading unmanaged memory:")
    ' Print the 10 elements of the C-style unmanagedArray
    For i As Integer = 0 To 9
        Console.WriteLine(Marshal.ReadInt16(unmanagedArray, i * elementSize))
    Next i

    Marshal.FreeHGlobal(unmanagedArray)

    Console.WriteLine("Done. Press Enter to continue.")
    Console.ReadLine()
End Sub

The following example demonstrates how to use the ReadInt16 method to read the value of an unmanaged short variable.


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



void main()
{
    // Create an unmanaged short.
    short myShort = 42;

    // Read the short as a managed Int16.
        Int16 ^ myManagedVal = Marshal::ReadInt16((IntPtr) &myShort);

    // Display the value to the console.
    Console::WriteLine(myManagedVal);
}

Remarks

ReadInt16 has an implied offset of 0. This method enables direct interaction with an unmanaged C-style Int16 array, eliminating the expense of copying an entire unmanaged array (using Marshal.Copy) to a separate managed array before reading its element values.

Reading from unaligned memory locations is supported.

See also

Applies to

ReadInt16(IntPtr, Int32)

Source:
Marshal.cs
Source:
Marshal.cs
Source:
Marshal.cs

Reads a 16-bit signed integer at a given offset from unmanaged memory.

public:
 static short ReadInt16(IntPtr ptr, int ofs);
[System.Security.SecurityCritical]
public static short ReadInt16 (IntPtr ptr, int ofs);
public static short ReadInt16 (IntPtr ptr, int ofs);
[<System.Security.SecurityCritical>]
static member ReadInt16 : nativeint * int -> int16
static member ReadInt16 : nativeint * int -> int16
Public Shared Function ReadInt16 (ptr As IntPtr, ofs As Integer) As Short

Parameters

ptr
IntPtr

nativeint

The base address in unmanaged memory from which to read.

ofs
Int32

An additional byte offset, which is added to the ptr parameter before reading.

Returns

The 16-bit signed integer read from unmanaged memory at the given offset.

Attributes

Exceptions

Base address (ptr) plus offset byte (ofs) produces a null or invalid address.

Examples

The following example demonstrates how to read and write to an unmanaged array using the ReadInt16 and WriteInt16 methods.

static void ReadWriteInt16()
{
    // Allocate unmanaged memory. 
    int elementSize = 2;
    IntPtr unmanagedArray = Marshal.AllocHGlobal(10 * elementSize);

    // Set the 10 elements of the C-style unmanagedArray
    for (int i = 0; i < 10; i++)
    {
        Marshal.WriteInt16(unmanagedArray, i * elementSize, ((Int16)(i + 1)));
    }
    Console.WriteLine("Unmanaged memory written.");

    Console.WriteLine("Reading unmanaged memory:");
    // Print the 10 elements of the C-style unmanagedArray
    for (int i = 0; i < 10; i++)
    {
        Console.WriteLine(Marshal.ReadInt16(unmanagedArray, i * elementSize));
    }

    Marshal.FreeHGlobal(unmanagedArray);

    Console.WriteLine("Done. Press Enter to continue.");
    Console.ReadLine();
}
Sub ReadWriteInt16()
    ' Allocate unmanaged memory. 
    Dim elementSize As Integer = 2
    Dim unmanagedArray As IntPtr = Marshal.AllocHGlobal(10 * elementSize)

    ' Set the 10 elements of the C-style unmanagedArray
    For i As Integer = 0 To 9
        Marshal.WriteInt16(unmanagedArray, i * elementSize, CType(i + 1, Int16))
    Next i
    Console.WriteLine("Unmanaged memory written.")

    Console.WriteLine("Reading unmanaged memory:")
    ' Print the 10 elements of the C-style unmanagedArray
    For i As Integer = 0 To 9
        Console.WriteLine(Marshal.ReadInt16(unmanagedArray, i * elementSize))
    Next i

    Marshal.FreeHGlobal(unmanagedArray)

    Console.WriteLine("Done. Press Enter to continue.")
    Console.ReadLine()
End Sub

The following example demonstrates how to use the ReadInt16 method to read the value of an unmanaged short variable.


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

void main()
{
    // Create an unmanaged short pointer.
    short * myShort;
    short tmp = 42;
    // Initialize it to another value.
    myShort = &tmp;

    // Read value as a managed Int16.
    Int16 ^ myManagedVal = Marshal::ReadInt16((IntPtr) myShort, 0);

    // Display the value to the console.
    Console::WriteLine(myManagedVal);
}

Remarks

ReadInt16 enables direct interaction with an unmanaged 16-bit signed array, eliminating the expense of copying an entire unmanaged array (using Marshal.Copy) to a separate managed array before reading its element values.

Reading from unaligned memory locations is supported.

See also

Applies to

ReadInt16(Object, Int32)

Source:
Marshal.CoreCLR.cs
Source:
Marshal.CoreCLR.cs
Source:
Marshal.CoreCLR.cs

Caution

ReadInt16(Object, Int32) may be unavailable in future releases.

Reads a 16-bit signed integer at a given offset from unmanaged memory.

public:
 static short ReadInt16(System::Object ^ ptr, int ofs);
[System.Obsolete("ReadInt16(Object, Int32) may be unavailable in future releases.")]
[System.Security.SecurityCritical]
public static short ReadInt16 (object ptr, int ofs);
[System.Obsolete("ReadInt16(Object, Int32) may be unavailable in future releases.")]
public static short ReadInt16 (object ptr, int ofs);
public static short ReadInt16 (object ptr, int ofs);
[System.Security.SecurityCritical]
public static short ReadInt16 (object ptr, int ofs);
[<System.Obsolete("ReadInt16(Object, Int32) may be unavailable in future releases.")>]
[<System.Security.SecurityCritical>]
static member ReadInt16 : obj * int -> int16
[<System.Obsolete("ReadInt16(Object, Int32) may be unavailable in future releases.")>]
static member ReadInt16 : obj * int -> int16
static member ReadInt16 : obj * int -> int16
[<System.Security.SecurityCritical>]
static member ReadInt16 : obj * int -> int16
Public Shared Function ReadInt16 (ptr As Object, ofs As Integer) As Short

Parameters

ptr
Object

The base address in unmanaged memory of the source object.

ofs
Int32

An additional byte offset, which is added to the ptr parameter before reading.

Returns

The 16-bit signed integer read from unmanaged memory at the given offset.

Attributes

Exceptions

Base address (ptr) plus offset byte (ofs) produces a null or invalid address.

ptr is an ArrayWithOffset object. This method does not accept ArrayWithOffset parameters.

Remarks

ReadInt16 enables direct interaction with an unmanaged 16-bit signed array, eliminating the expense of copying an entire unmanaged array (using Marshal.Copy) to a separate managed array before reading its element values.

Reading from unaligned memory locations is supported.

See also

Applies to