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memcpy (msvcrt)
Copies count bytes of src to dest. If the source and destination overlap, the behavior of memcpy is undefined. Use memmove to handle overlapping regions.

C# Signature:

[DllImport("msvcrt.dll", EntryPoint = "memcpy", CallingConvention = CallingConvention.Cdecl, SetLastError = false)]
public static extern IntPtr memcpy(IntPtr dest, IntPtr src, UIntPtr count);

VB.NET Signature:

    <DllImport("msvcrt.dll", EntryPoint:="memcpy", CallingConvention:=CallingConvention.StdCall)> _
    Public Sub CopyMemory(ByVal dest As IntPtr, ByVal src As IntPtr, ByVal count As Integer)
    End Sub

VB Signature:

Declare Function memcpy Lib "msvcrt.dll" (TODO) As TODO

Return Value:

The value of dest.

User-Defined Types:


Alternative Managed API:

System.Buffer.BlockCopy, Marshal.Copy and Array.Copy provide similar services, but require one or two managed arrays instead of pointers.



Tips & Tricks:

Please add some!

Sample Code:

Please add some!

'Prima mi creo da un vettore di caratteri una area di memoria non gestita con la stringa "Ciao"

'quindi la copio in un altra area non gestita con MemCpy, e quindi la ritrasformo in un vettore

'di caratteri, che posso quindi convertire in una stringa !!!

'Provato e testato. Funziona.

'Salute a tutti.

'Andrea Casagrande

Imports System.Runtime.InteropServices

    Sub Main()
    Dim managedArray1 As Char() = ("Ciao").ToCharArray
    Dim size As Integer = Marshal.SizeOf(managedArray1(0)) * managedArray1.Length
    Dim pnt1 As IntPtr = Marshal.AllocHGlobal(size)
    Dim pnt2 As IntPtr = Marshal.AllocHGlobal(size)
    Dim managedArray2(managedArray1.Length - 1) As Char
        Marshal.Copy(managedArray1, 0, pnt1, managedArray1.Length)
        CopyMemory(pnt2, pnt1, size * 2)
        Marshal.Copy(pnt2, managedArray2, 0, managedArray2.Length)
    End Try
    Dim value As String = New String(managedArray2)
    Console.WriteLine(">>" + value + "<<")

    End Sub

memcpy on MSDN

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