Marshal.Copy Method (IntPtr, Int32(), Int32, Int32)


The .NET API Reference documentation has a new home. Visit the .NET API Browser on to see the new experience.

Copies data from an unmanaged memory pointer to a managed 32-bit signed integer array.

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

Public Shared Sub Copy (
	source As IntPtr,
	destination As Integer(),
	startIndex As Integer,
	length As Integer


Type: System.IntPtr

The memory pointer to copy from.

Type: System.Int32()

The array to copy to.

Type: System.Int32

The zero-based index in the destination array where copying should start.

Type: System.Int32

The number of array elements to copy.

Exception Condition

source, destination, startIndex, or length is null.

Unmanaged, C-style arrays do not contain bounds information, which prevents the startIndex and length parameters from being validated. Thus, the unmanaged data corresponding to the source parameter populates the managed array regardless of its usefulness. You must initialize the managed array with the appropriate size before calling this method.

The following example copies an array to unmanaged memory and then copies the unmanaged array back to managed memory.

Imports System
Imports System.Runtime.InteropServices

Module Example

    Sub Main()
        ' Create a managed array.
        Dim managedArray As Integer() = {1, 2, 3, 4}

        ' Initialize unmanaged memory to hold the array.
        Dim size As Integer = Marshal.SizeOf(managedArray(0)) * managedArray.Length

        Dim pnt As IntPtr = Marshal.AllocHGlobal(size)

            ' Copy the array to unmanaged memory.
            Marshal.Copy(managedArray, 0, pnt, managedArray.Length)

            ' Copy the unmanaged array back to another managed array.
            Dim managedArray2(managedArray.Length) As Integer

            Marshal.Copy(pnt, managedArray2, 0, managedArray.Length)

            Console.WriteLine("The array was copied to unmanaged memory and back.")

            ' Free the unmanaged memory.
        End Try

    End Sub
End Module


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

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
Return to top