CWnd::OnDeviceChange

  • 项目

afx_msg BOOL OnDeviceChange( UINT nEventType**, DWORD** dwData );

Parameters

nEventType

An event type. See the Remarks section for a description of the available values

dwData

The address of a structure that contains event-specific data. Its meaning depends on the given event.

Remarks

The framework calls this member function to notify an application or device driver of a change to the hardware configuration of a device or the computer.

For devices that offer software-controllable features, such as ejection and locking, the operating system typically sends a DBT_DEVICEREMOVEPENDING message to let applications and device drivers end their use of the device gracefully.

If the operating system forcefully removes of a device, it may not send a DBT_DEVICEQUERYREMOVE message before doing so.

The nEvent parameter can be one of these values:

  •    A device has been inserted and is now available.

  •    Permission to remove a device is requested. Any application can deny this request and cancel the removal.

  •    Request to remove a device has been canceled.

  •    Device is about to be removed. Cannot be denied.

  •    Device has been removed.

  •    Device-specific event.

  •    Current configuration has changed.

  • DBT_DEVNODES_CHANGED   Device node has changed.

Note   This member function is called by the framework to allow your application to handle a Windows message. The parameters passed to your function reflect the parameters received by the framework when the message was received. If you call the base-class implementation of this function, that implementation will use the parameters originally passed with the message and not the parameters you supply to the function.

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See Also