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This function sends a CLEAR_FEATURE request to a USB device.
USB_TRANSFER ClearFeature(USB_HANDLE hDevice , LPTRANSFER_NOTIFY_ROUTINE lpStartAddress , LPVOID lpvNotifyParameter , DWORD dwFlags , WORD wFeature , UCHAR bIndex );
|USB_SEND_TO_DEVICE||Request for device.|
|USB_SEND_TO_INTERFACE||Request for interface.|
|USB_SEND_TO_ENDPOINT||Request for endpoint.|
A USB_TRANSFER handle indicates success. NULL indicates failure.
This function, like all other Windows CE USBDI functions, is not directly accessible by any client drivers. It is invoked by dereferencing the lpClearFeaturefield of the USB_FUNCS structure passed to the client driver in the invocation of its USBDeviceAttach function.
This function initiates a control transfer to a USB device, requesting that a specified feature be disabled. The USB 1.1 specification defines features and appropriate feature request recipients. There is no facility for class- or vendor-specific feature selectors; vendors who need to implement non-standard operations should use vendor-specific requests rather than the standard requests.
Sucessful return from this function indicates that the request was issued to the device (or queued for issuing if USB_NO_WAIT was set); it does not mean that the feature was actually cleared. You must wait for and check the transfer completion status to determine if the device was able to clear the feature or not.
|Runs on||Versions||Defined in||Include||Link to|
|Windows CE OS||2.10 and later|
Note This API is part of the complete Windows CE OS package as provided by Microsoft. The functionality of a particular platform is determined by the original equipment manufacturer (OEM) and some devices may not support this API.
Last updated on Tuesday, July 13, 2004