Using Win32 functions in Visual FoxPro Image Gallery
Device Input and Output
..msdn
DeviceIoControl
Code examples:
Obtaining physical parameters for a drive: sectors, clusters, cylinders...
DeviceIoControl
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Sends a control code directly to a specified device driver, causing the corresponding device to perform the corresponding operation.
Code examples:
Obtaining physical parameters for a drive: sectors, clusters, cylinders...
Declaration:
BOOL DeviceIoControl(
  HANDLE hDevice,
  DWORD dwIoControlCode,
  LPVOID lpInBuffer,
  DWORD nInBufferSize,
  LPVOID lpOutBuffer,
  DWORD nOutBufferSize,
  LPDWORD lpBytesReturned,
  LPOVERLAPPED lpOverlapped
);
FoxPro declaration:
DECLARE INTEGER DeviceIoControl IN kernel32;
    INTEGER   hDevice,;
    INTEGER   dwIoControlCode,;
    STRING  @ lpInBuffer,;
    INTEGER   nInBufferSize,;
    STRING  @ lpOutBuffer,;
    INTEGER   nOutBufferSize,;
    INTEGER @ lpBytesReturned,;
    INTEGER   lpOverlapped

Parameters:
hDevice
[in] Handle to the device on which the operation is to be performed.

dwIoControlCode
[in] Control code for the operation.

lpInBuffer
[in] Pointer to the input buffer that contains the data required to perform the operation.

nInBufferSize
[in] Size of the input buffer, in bytes.

lpOutBuffer
[out] Pointer to the output buffer that is to receive the data returned by the operation.

nOutBufferSize
[in] Size of the output buffer, in bytes.

lpBytesReturned
[out] Pointer to a variable that receives the size of the data stored in the output buffer, in bytes.

lpOverlapped
[in] Pointer to an OVERLAPPED structure.
Return value:
If the function succeeds, the return value is nonzero.
My comment:
To retrieve a handle to the device, you must call the CreateFile function with either the name of a device or the name of the driver associated with a device.

To specify a device name, use the following format: \\.\DeviceName

Other valid device names:
\\.\a:
\\.\PhysicalDrive0
\\.\PhysicalDrive1
\\.\vwin32
Word Index links for the DeviceIoControl :
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Created: 2004-09-09 18:31:40
Modified: 2004-09-09 18:37:15
Visited in last 7 days: 38
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