Readfile读取不到USB的数据。

[my_westlife]

改了别人的USB程序，但是程序却读不到USB传上来的数据。我的数据可以传下去。但是去不能读出来这是怎么回事呢？难道要写一个全局的HOOK来读数据？但是HOOK能HOOK到USB的数据吗？

[一名程序员]

把代码贴出来才好判断！

[my_westlife]

这是读数据的代码：
void CHid::ReadHid(unsigned char ucDataBuffer[], unsigned char ucDataLength)
{

HANDLE hDevice;
unsigned long numBytesReturned;
unsigned char inbuffer[128]; /* input buffer*/
BOOL bResult;
HIDP_CAPS Capabilities;
PHIDP_PREPARSED_DATA HidParsedData;
OVERLAPPED HidOverlapped;
HANDLE ReportEvent;

if(!m_bMyDeviceDetected)
return;

/* Open the HID device handle */
if(OpenHidDevice( &hDevice, VID, PID) == TRUE)
{

HidD_GetPreparsedData(hDevice, &HidParsedData);

/* extract the capabilities info */
HidP_GetCaps( HidParsedData ,&Capabilities);

/* Free the memory allocated when getting the preparsed data */
HidD_FreePreparsedData(HidParsedData);

/* Create a new event for report capture */
ReportEvent = CreateEvent(NULL, TRUE, FALSE, NULL);

/* fill the HidOverlapped structure so that Windows knows which
event to cause when the device sends an IN report */
HidOverlapped.hEvent = ReportEvent;
HidOverlapped.Offset = 0;
HidOverlapped.OffsetHigh = 0;
bResult = ReadFile( hDevice, /* handle to device */
&inbuffer[0], /* IN report buffer to fill */
Capabilities.InputReportByteLength, /* input buffer size */
ucDataLength+1, //如果ucDataLength的值为64的话,Capabilities.InputReportByteLength就为65
&numBytesReturned, /* returned buffer size */
(LPOVERLAPPED) &HidOverlapped ); /* long pointer to an OVERLAPPED structure */

bResult = WaitForSingleObject( ReportEvent, 600);
/* if the transaction timed out, then we have to manually cancel
the request */
if(bResult == WAIT_TIMEOUT || bResult == WAIT_ABANDONED)
CancelIo(&hDevice);

if(bResult == WAIT_OBJECT_0)
{
//Save data to ucDataBuffer(this parameter will return by this funciotn)
for(int i=0;i<ucDataLength;i++)
{
ucDataBuffer[i] = inbuffer[i+1];
TRACE("0x%.2X ",ucDataBuffer[i]);
}
TRACE("\n");

}

/* close the HID device handle */
CloseHandle(hDevice);
}

}