c/c++语言开发共享ReadFile和Overlapped出错

我有ReadFile和重叠的问题。

首先我使用与0重叠的ReadFile

ZeroMemory(&overlapped ,sizeof(OVERLAPPED)); hDevice = CreateFileW(zwpath, GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED, NULL); if(hDevice != INVALID_HANDLE_VALUE){ ret = ReadFile(hDevice, buff, 1024, &numerobyte, &overlapped); } 

使用for(),我可以使用printf()查看字节

  for (int n=0; n<sizeof(buff); n++) { printf("0x%02X ", buff[n]); } 

现在我有一个大数字的变种

 crbig = 322122547 d1 = (DWORD*)crbig; overlapped.Offset = d1[1]; //22122547 overlapped.OffsetHigh = d1[0];// 00000003 

我需要两次使用ReafFile,第二次使用带有偏移和高偏移值的重叠()

  d1 = (DWORD*)&crbig; overlapped.Offset = d1[1]; overlapped.OffsetHigh = d1[0]; ret = ReadFile(hDevice, buff, 1024, &numerobyte, &overlapped); 

但是for()打印出相同的字节,它会抛出第一个ReadFile,我尝试用memset()清理缓冲区或使用另一个缓冲区,但总是向我显示相同的字节

据说Overlapped()说ReadFile应该去哪里,并读取1024个字节,并将其保存在缓冲区中,但没有任何反应,缓冲区具有重叠的相同的第一个字节()= 0

这是完整的代码

 int main(int argc, char *argv[]){ HANDLE hDevice; OVERLAPPED overlapped; DWORD crbig; BYTE buff[1024] = {0}; DWORD numerobyte = 0, nbytes = 0; UINT32 ret; DWORD *d1; int offset1 = 11, offset2 = 13, offset3 = 30; long MFTCluster = 0, bytespercluster = 0, sectperclusters = 0, offet = 0; unsigned long mult = 0; ZeroMemory(&overlapped ,sizeof(OVERLAPPED)); hDevice = CreateFileW(zwpath, GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED, NULL); if(hDevice != INVALID_HANDLE_VALUE){ ret = ReadFile(hDevice, buff, 1024, &numerobyte, &overlapped); }else { return NULL; } if(ret == 0){ ret = WaitForSingleObject(hDevice,INFINITE ); switch (ret) { case WAIT_OBJECT_0:break; case WAIT_TIMEOUT:break; default: break; } } else { return NULL; } if((int)buff[3] == 'N' && (int)buff[4] == 'T' && (int)buff[5] == 'F' && (int)buff[6] == 'S' ){ printf("Volumen es formato NTFSnnn"); } bytespercluster = endianhextodec(buff, offset1); sectperclusters = endianhextodec(buff, offset2); MFTCluster = endianhextodec(buff, offset3); crbig = (sectperclusters * (bytespercluster * MFTCluster)); d1 = (DWORD*)&crbig; overlapped.Offset = d1[1]; overlapped.OffsetHigh = d1[0]; ret = ReadFile(hDevice, buff, 1024, &numerobyte, &overlapped); if(ret == 0){ ret = WaitForSingleObject(hDevice,INFINITE ); switch (ret) { case WAIT_OBJECT_0:break; default: break; } } else { return NULL; } for (int n=0; n<sizeof(buff); n++) { printf("0x%02X ", buff[n]); } CloseHandle(hDevice); getchar(); } 

VB.NET

 Private Sub SetReadFileOffset(ByRef NO As System.Threading.NativeOverlapped, ByRef curBig As Int64) Dim lowoffset() As Byte = BitConverter.GetBytes(curBig) Dim highoffset As Int32 = BitConverter.ToInt32(lowoffset, 0) Dim high As Int32 Dim lastbytes(3) As Byte Array.Copy(lowoffset, 4, lastbytes, 0, 4) high = BitConverter.ToInt32(lastbytes, 0) NO.OffsetLow = highoffset NO.OffsetHigh = high End Sub SetReadFileOffset(NO, MFTCluster * SectperCluster * BytesPerSect) ret = ReadFile(Hnd, Buffer, 1024, nRead, NO) If ret = 0 Then ret = WaitForSingleObject(Hnd, INFINITE) Select Case ret Case WAIT_OBJECT_0 Case Else End Select Else Return Nothing End If 

      以上就是c/c++开发分享ReadFile和Overlapped出错相关内容,想了解更多C/C++开发(异常处理)及C/C++游戏开发关注(计算机技术网)。

      本文来自网络收集,不代表计算机技术网立场,如涉及侵权请点击右边联系管理员删除。

      如若转载,请注明出处:https://www.ctvol.com/c-cdevelopment/522881.html

      (0)
      上一篇 2020年12月11日
      下一篇 2020年12月11日

      精彩推荐