C写档速度问题

Option Explicit

Private Declare Function Write1 Lib "Write1.dll" (ByVal FN As String, ByVal iCount As Long, ByVal A As Long) As Long

Private Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)
Private Declare Function GetSystemDirectory Lib "kernel32" Alias "GetSystemDirectoryA" (ByVal lpbuffer As String, ByVal nSize As Long) As Long
Private Declare Function SetCurrentDirectory Lib "kernel32" Alias "SetCurrentDirectoryA" (ByVal lpPathName As String) As Long
Private Declare Function QueryPerformanceCounter Lib "kernel32" (X As Currency) As Boolean
Private Declare Function QueryPerformanceFrequency Lib "kernel32" (X As Currency) As Boolean

Dim S1 As Currency, S2 As Currency, f As Currency, t1 As Currency   
Dim iSize(25600) As Long, Myindex As Integer, iTime(25600) As Currency, iCount As Integer

Private Sub Form_Activate()
Dim i As Integer

    List1.Clear
    List2.Clear
   
    For i = 0 To 25600
        List1.AddItem i & " : " & iSize(i), i
        List2.AddItem i & " : " & iTime(i), i
    Next i
   
End Sub

Private Sub Form_Load()
Dim i As Integer, A() As Byte, j As Integer, k As Long
   
    For i = 0 To 25600
   
        ReDim A(256)
        For j = 0 To 256
            A(j) = i Mod 256
        Next j
        
        Call QueryPerformanceFrequency(f)      
        Call QueryPerformanceCounter(S1)      
        
        Call WaitEXE(Write1("C:\AAA.std", 256, VarPtr(A(0))), iCount)
        
        Call QueryPerformanceCounter(S2)      
        
        iTime(iCount) = (S2 - S1) / f
        iCount = iCount + 1
    Next i
   
End Sub

Private Sub WaitEXE(k As Long, m As Integer)
    Do
        If k = 1 Then
            iSize(m) = k
            Exit Do
        End If
        MyDoEvents 100
    Loop
End Sub

Private Function MyDoEvents(Optional ByVal dwMilliseconds As Long = 1)

   MyDoEvents = DoEvents()
   Sleep dwMilliseconds
   
End Function

// Write1.cpp : Defines the entry point for the DLL application.
//

#include "stdafx.h"
#include <stdio.h>

BOOL APIENTRY DllMain( HANDLE hModule,
                       DWORD  ul_reason_for_call,
                       LPVOID lpReserved
                     )
{
    return TRUE;
}

int _stdcall Write1(char *FN, int Count, int *A)
{
    int i=0,nwDataSize=0;
    long size=0;

    FILE *stream = fopen( FN, "ab+" );

    if( stream != NULL )
    {
        fseek(stream,0,SEEK_END);
        size=ftell(stream);
        nwDataSize =fwrite(&A[0],sizeof (char), Count, stream);
    }
    else
        return 0;

    fclose(stream);

    return 1;
}