急求关于USB通讯的问题

[wdjust]

大家好：
正在写一个USB通讯的程序：

#include "setupapi.h"
#define USBIO_IID {0x325ddf96, 0x938c, 0x11d3, {0x9e, 0x34, 0x00, 0x80, 0xc8, 0x27, 0x27, 0xf4}}
#define DEVICE_NUMBER 0
HDEVINFO DevInfo;

	  GUID g_UsbioID=USBIO_IID;
	  SP_DEVICE_INTERFACE_DATA DevData;
	  SP_INTERFACE_DEVICE_DETAIL_DATA *DevDetail = NULL;
	  DWORD ReqLen;
	  DevInfo=SetupDiGetClassDevs(&g_UsbioID,NULL,NULL,DIGCF_DEVICEINTERFACE|DIGCF_PRESENT);
	  SetupDiEnumDeviceInterfaces(DevInfo, NULL,&g_UsbioID, DEVICE_NUMBER, &DevData );  //返回值为0
	  DWORD code =GetLastError();       //错误代码1784
	  SetupDiGetDeviceInterfaceDetail(DevInfo, &DevData, NULL,0, &ReqLen, NULL);
	  DWORD ni =GetLastError();
	  DevDetail = (SP_INTERFACE_DEVICE_DETAIL_DATA*) malloc(ReqLen);
	  // now get the detailed device information
	  DevDetail->cbSize = sizeof(SP_INTERFACE_DEVICE_DETAIL_DATA);
	  SetupDiGetDeviceInterfaceDetail(DevInfo, &DevData, DevDetail,ReqLen, &ReqLen, NULL);
	  // open the device, use OVERLAPPED flag if necessary
	  // use DevDetail->DevicePath as device name
	  hdle = CreateFile(DevDetail->DevicePath,GENERIC_READ|GENERIC_WRITE,FILE_SHARE_WRITE|FILE_SHARE_READ,NULL,OPEN_EXISTING,0,NULL);

错误代码1784看了半天也没找到原因，急求，谢谢。在别的地方开帖给分

[wdjust]

没人回复啊？？

[jodan179]

这代码帖的，错误代码1784----是指error的代号，还是第1784行有错误？

[stecdeng]

ERROR_INVALID_USER_BUFFER 1784

[Saleayas]

SP_DEVICE_INTERFACE_DATA 需要设置 cbSize.