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Marshal.ReadInt16 Method (IntPtr)

Reads a 16-bit signed integer from unmanaged memory.

Namespace:  System.Runtime.InteropServices
Assembly:  mscorlib (in mscorlib.dll)

public static short ReadInt16(
	IntPtr ptr
)

Parameters

ptr
Type: System.IntPtr

The address in unmanaged memory from which to read.

Return Value

Type: System.Int16
The 16-bit signed integer read from unmanaged memory.

ExceptionCondition
AccessViolationException

ptr is not a recognized format.

-or-

ptr is null.

-or-

ptr is invalid.

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.

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();
}

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);
}

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0

Portable Class Library

Supported in: Portable Class Library

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8

  • SecurityCriticalAttribute 

    requires full trust for the immediate caller. This member cannot be used by partially trusted or transparent code.

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