C# Signature:

    public enum EMoveMethod : uint
    {
        Begin = 0,
        Current = 1,
        End = 2
    }
[DllImport("kernel32.dll")]
static extern bool SetFilePointer(IntPtr hFile, Int32 lDistanceToMove,
   out Int32 lpDistanceToMoveHigh, UInt32 dwMoveMethod);

    [DllImport("Kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
    static extern unsafe uint SetFilePointer(
        [In] SafeFileHandle hFile,
        [In] int lDistanceToMove,
        [Out] int* lpDistanceToMoveHigh,
        [In] EMoveMethod dwMoveMethod);

C# Signature:

[DllImport("kernel32.dll")]
public static extern bool SetFilePointer(
     Microsoft.Win32.SafeHandles.SafeFileHandle hFile, Int32 lDistanceToMove,
     [In, Out] ref Int32 lpDistanceToMoveHigh, UInt32 dwMoveMethod);

    [DllImport("Kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
    static extern uint SetFilePointer(
        [In] SafeFileHandle hFile,
        [In] int lDistanceToMove,
        [Out] out int lpDistanceToMoveHigh,
        [In] EMoveMethod dwMoveMethod);

User-Defined Types:

None.

VB Signature:

    Public Enum EMoveMethod As System.UInt32
        FILE_BEGIN = 0
        FILE_CURRENT = 1
        FILE_END = 2
    End Enum
public enum EMoveMethod : uint
{
    Begin = 0,
    Current = 1,
    End = 2
}

    <DllImport("kernel32.dll", SetLastError:=True)> _
    Shared Function SetFilePointer( _
        ByVal hFile As IntPtr, _
        ByVal lDistanceToMove As Integer, _
        ByRef lpDistanceToMoveHigh As IntPtr, _
        ByVal dwMoveMethod As EMoveMethod) _
        As System.UInt32
    End Function

    Public Const INVALID_SET_FILE_POINTER As Integer = -1

Notes:

If you are using this function to access hard-disk sectors greater than (2^32 - 2) bytes,

then the third argument will not be null or IntPtr.Zero. So when you pass an IntPtr to

the third argument, pass it as a reference. To do this, just change the third argument signature

to: ref IntPtr lpDistanceToMoveHigh.

None.

Tips & Tricks:

Please add some!

Sample Code:

    [DllImport("Kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
    private static extern int SetFilePointer(IntPtr handle, int lDistanceToMove, out int lpDistanceToMoveHigh, uint dwMoveMethod);
//https://stackoverflow.com/a/13825695

    public long Seek(IntPtr handle, long offset, SeekOrigin origin)
    {
    uint moveMethod = 0;
var text = "Here is some text to put in the test file";
File.WriteAllText(@"c:\temp\test.txt", text);
var file = File.Open(@"c:\temp\test.txt", FileMode.OpenOrCreate);
int moveDistance = 10;
int moveDistanceHighBits = 0;
uint retvalUint = SetFilePointer(file.SafeFileHandle, moveDistance, ref moveDistanceHighBits, EMoveMethod.Begin);
Debug.Assert(Encoding.ASCII.GetBytes(text)[moveDistance] == file.ReadByte());

    switch (origin)
    {
        case SeekOrigin.Begin:
        moveMethod = 0;
        break;

        case SeekOrigin.Current:
        moveMethod = 1;
        break;

Alternative Managed API:

Do you know one? Please contribute it!

        case SeekOrigin.End:
        moveMethod = 2;
        break;
    }

    int lo = (int)(offset & 0xffffffff);
    int hi = (int)(offset >> 32);

    lo = SetFilePointer(handle, lo, out hi, moveMethod);

    if (lo == -1)
    {
        if (GetLastError() != 0)
        {
        throw new Exception("INVALID_SET_FILE_POINTER");
        }
    }

    return (((long)hi << 32) | (uint)lo);
    }

Alternative Managed API:

Do you know one? Please contribute it!

Please edit this page!

Do you have...

• helpful tips or sample code to share for using this API in managed code?
• corrections to the existing content?
• variations of the signature you want to share?
• additional languages you want to include?

Select "Edit This Page" on the right hand toolbar and edit it! Or add new pages containing supporting types needed for this API (structures, delegates, and more).