IOCTL_BATTERY_QUERY_STATUS control code

Retrieves the current status of the battery.

To perform this operation, call the DeviceIoControl function with the following parameters.


BOOL DeviceIoControl(
  (HANDLE) hDevice,           // handle to battery
  IOCTL_BATTERY_QUERY_STATUS, // dwIoControlCode
  (LPVOID) lpInBuffer,        // input buffer
  (DWORD) nInBufferSize,      // size of input buffer
  (LPVOID) lpOutBuffer,       // output buffer
  (DWORD) nOutBufferSize,     // size of output buffer
  (LPDWORD) lpBytesReturned,  // number of bytes returned
  (LPOVERLAPPED) lpOverlapped // OVERLAPPED structure
);

Parameters

hDevice

A handle to the battery from which information is to be returned. To retrieve a device handle, call the CreateFile function.

dwIoControlCode

The control code for the operation. This value identifies the specific operation to be performed and the type of device on which to perform it. Use IOCTL_BATTERY_QUERY_STATUS for this operation.

lpInBuffer

A pointer to a BATTERY_WAIT_STATUS structure.

nInBufferSize

The size of the input buffer, in bytes.

lpOutBuffer

A pointer to a BATTERY_STATUS structure.

nOutBufferSize

The size of the output buffer, in bytes.

lpBytesReturned

A pointer to a variable that receives the size of the data returned in the lpOutBuffer buffer, in bytes.

If the output buffer is too small to return any data then the call fails, GetLastError returns the error code ERROR_INSUFFICIENT_BUFFER, and the returned byte count is zero.

If lpOverlapped is NULL (nonoverlapped I/O), lpBytesReturned cannot be NULL.

If lpOverlapped is not NULL (overlapped I/O), lpBytesReturned can be NULL. If this is an overlapped operation, you can retrieve the number of bytes returned by calling the GetOverlappedResult function. If hDevice is associated with an I/O completion port, you can get the number of bytes returned by calling the GetQueuedCompletionStatus function.

lpOverlapped

A pointer to an OVERLAPPED structure.

If hDevice was opened with the FILE_FLAG_OVERLAPPED flag, lpOverlapped must point to a valid OVERLAPPED structure. In this case, DeviceIoControl is performed as an overlapped (asynchronous) operation. If the device was opened with the FILE_FLAG_OVERLAPPED flag and lpOverlapped is NULL, the function fails in unpredictable ways.

If hDevice was opened without specifying the FILE_FLAG_OVERLAPPED flag, lpOverlapped is ignored and the DeviceIoControl function does not return until the operation has been completed, or until an error occurs.

Return value

If the operation completes successfully, DeviceIoControl returns a nonzero value.

If the operation fails or is pending, DeviceIoControl returns zero. To get extended error information, call GetLastError.

Remarks

This battery IOCTL retrieves the status of the battery at the time the operation returns. The input parameter structure, BATTERY_WAIT_STATUS, indicates when the battery status is to be processed and returned.

Requests for battery status can be for immediate return or can be set to wait for a particular condition before completing. For example, a request for battery information can be made that waits until the battery capacity reaches a specified point or the battery state changes.

All requests for battery information will complete with the status of ERROR_FILE_NOT_FOUND whenever the BatteryTag element of the request does not match that of the current battery tag. (See Battery Tags for more information.) This is used to ensure that the returned battery information matches that of the requested battery.

For the implications of overlapped I/O on this operation, see the Remarks section of the DeviceIoControl topic.

Examples

For an example, see Enumerating Battery Devices.

Requirements

Minimum supported client

Windows XP [desktop apps only]

Minimum supported server

Windows Server 2003 [desktop apps only]

Header

Poclass.h;
BatClass.h on Windows Server 2008 R2, Windows 7, Windows Server 2008, Windows Vista, Windows Server 2003, and Windows XP

See also

Battery Information
Power Management Control Codes
DeviceIoControl
BATTERY_STATUS
BATTERY_WAIT_STATUS
IOCTL_BATTERY_QUERY_INFORMATION
IOCTL_BATTERY_QUERY_TAG
IOCTL_BATTERY_SET_INFORMATION

 

 

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