Marshal.WriteInt64 Method

Definition

Namespace:

System.Runtime.InteropServices

Assembly:

System.Runtime.InteropServices.dll

Writes a 64-bit signed integer value to unmanaged memory. Writing to unaligned memory locations is supported.

Overloads

WriteInt64(Object, Int32, Int64)	Obsolete. Writes a 64-bit signed integer value to unmanaged memory at a specified offset.
WriteInt64(IntPtr, Int64)	Writes a 64-bit signed integer value to unmanaged memory.
WriteInt64(IntPtr, Int32, Int64)	Writes a 64-bit signed integer value to unmanaged memory at a specified offset.

WriteInt64(Object, Int32, Int64)

Source:

Marshal.CoreCLR.cs

Caution

WriteInt64(Object, Int32, Int64) may be unavailable in future releases.

Writes a 64-bit signed integer value to unmanaged memory at a specified offset.

public:
 static void WriteInt64(System::Object ^ ptr, int ofs, long val);

[System.Obsolete("WriteInt64(Object, Int32, Int64) may be unavailable in future releases.")]
public static void WriteInt64 (object ptr, int ofs, long val);

[<System.Obsolete("WriteInt64(Object, Int32, Int64) may be unavailable in future releases.")>]
static member WriteInt64 : obj * int * int64 -> unit

Public Shared Sub WriteInt64 (ptr As Object, ofs As Integer, val As Long)

Parameters

ptr

Object

The base address in unmanaged memory of the target object.

ofs

Int32

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

val

Int64

The value to write.

Attributes

ObsoleteAttribute

Exceptions

AccessViolationException

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

ArgumentException

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

Remarks

WriteInt64 enables direct interaction with an unmanaged 64-bit signed array, eliminating the expense of copying an entire unmanaged array (using Marshal.Copy) to a separate managed array before setting its element values.

Writing to unaligned memory locations is supported.

See also

• Copy(Int32[], Int32, IntPtr, Int32)

WriteInt64(IntPtr, Int64)

Source:

Marshal.cs

Writes a 64-bit signed integer value to unmanaged memory.

public:
 static void WriteInt64(IntPtr ptr, long val);

public static void WriteInt64 (IntPtr ptr, long val);

static member WriteInt64 : nativeint * int64 -> unit

Public Shared Sub WriteInt64 (ptr As IntPtr, val As Long)

Parameters

ptr

IntPtr

nativeint

The address in unmanaged memory to write to.

val

Int64

The value to write.

Exceptions

AccessViolationException

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 ReadInt64 and WriteInt64 methods.

static void ReadWriteInt64()
{
    // Allocate unmanaged memory. 
    int elementSize = 8;
    IntPtr unmanagedArray = Marshal.AllocHGlobal(10 * elementSize);

    // Set the 10 elements of the C-style unmanagedArray
    for (int i = 0; i < 10; i++)
    {
        Marshal.WriteInt64(unmanagedArray, i * elementSize, ((Int64)(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.ReadInt64(unmanagedArray, i * elementSize));
    }

    Marshal.FreeHGlobal(unmanagedArray);

    Console.WriteLine("Done. Press Enter to continue.");
    Console.ReadLine();
}

Sub ReadWriteInt64()
    ' Allocate unmanaged memory. 
    Dim elementSize As Integer = 8
    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.WriteInt64(unmanagedArray, i * elementSize, CType(i + 1, Int64))
    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.ReadInt64(unmanagedArray, i * elementSize))
    Next i

    Marshal.FreeHGlobal(unmanagedArray)

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

Remarks

WriteInt64 enables direct interaction with an unmanaged 64-bit signed array, eliminating the expense of copying an entire unmanaged array (using Marshal.Copy) to a separate managed array before setting its element values.

Writing to unaligned memory locations is supported.

See also

• Copy(Int32[], Int32, IntPtr, Int32)

WriteInt64(IntPtr, Int32, Int64)

Source:

Marshal.cs

Writes a 64-bit signed integer value to unmanaged memory at a specified offset.

public:
 static void WriteInt64(IntPtr ptr, int ofs, long val);

public static void WriteInt64 (IntPtr ptr, int ofs, long val);

static member WriteInt64 : nativeint * int * int64 -> unit

Public Shared Sub WriteInt64 (ptr As IntPtr, ofs As Integer, val As Long)

Parameters

ptr

IntPtr

nativeint

The base address in unmanaged memory to write.

ofs

Int32

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

val

Int64

The value to write.

Exceptions

AccessViolationException

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 ReadInt64 and WriteInt64 methods.

static void ReadWriteInt64()
{
    // Allocate unmanaged memory. 
    int elementSize = 8;
    IntPtr unmanagedArray = Marshal.AllocHGlobal(10 * elementSize);

    // Set the 10 elements of the C-style unmanagedArray
    for (int i = 0; i < 10; i++)
    {
        Marshal.WriteInt64(unmanagedArray, i * elementSize, ((Int64)(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.ReadInt64(unmanagedArray, i * elementSize));
    }

    Marshal.FreeHGlobal(unmanagedArray);

    Console.WriteLine("Done. Press Enter to continue.");
    Console.ReadLine();
}

Sub ReadWriteInt64()
    ' Allocate unmanaged memory. 
    Dim elementSize As Integer = 8
    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.WriteInt64(unmanagedArray, i * elementSize, CType(i + 1, Int64))
    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.ReadInt64(unmanagedArray, i * elementSize))
    Next i

    Marshal.FreeHGlobal(unmanagedArray)

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

Remarks

WriteInt64 enables direct interaction with an unmanaged 64-bit signed array, eliminating the expense of copying an entire unmanaged array (using Marshal.Copy) to a separate managed array before setting its element values.

Writing to unaligned memory locations is supported.

See also

• Copy(Int32[], Int32, IntPtr, Int32)
• WriteByte(IntPtr, Int32, Byte)