Pnp​Object​Watcher Pnp​Object​Watcher Pnp​Object​Watcher Class

The status associated with the asynchronous operation.

public : DeviceWatcherStatus Status { get; }public DeviceWatcherStatus Status { get; }Public ReadOnly Property Status As DeviceWatcherStatus

Attributes

ContractVersionAttribute DualApiPartitionAttribute MarshalingBehaviorAttribute

Starts raising the events to inform the client that a PnpObject has been added, updated, or removed.

public : void Start()public void Start()Public Function Start() As void

Attributes

ContractVersionAttribute DualApiPartitionAttribute MarshalingBehaviorAttribute

Remarks

An app calls Start to begin the search for devices. During this intial enumeration, the PnpObjectWatcher raises an Added event for each device that's found, until all devices are found. The PnpObjectWatcher raises an EnumerationCompleted event when the initial enumeration is complete, and continues to raise events if a device is added, updated, or removed.

The Start method can only be called when the PnpObjectWatcher is in the Created, Stopped or Aborted state. The Status property indicates the PnpObjectWatcher state. When re-starting the watcher, wait for the Stopped event before calling Start.

The following diagram shows how the PnpObjectWatcher transitions between the states represented by DeviceWatcherStatus enumeration.

Stops raising the events to inform the client that a PnpObject has been added, updated, or removed.

public : void Stop()public void Stop()Public Function Stop() As void

Attributes

ContractVersionAttribute DualApiPartitionAttribute MarshalingBehaviorAttribute

Remarks

To stop a search for devices, an app calls Stop.

This call transitions the PnpObjectWatcher to the Stopping state and completes immediately. The watcher will transition to the Stopped state once all events that are already in the process of being raised have completed.

Callers may wait for the Stopped event if they need to know when the PnpObjectWatcher has stopped. Callers must wait for the Stopped event before they can call Start to restart the watcher. Callers may unsubscribe from events if they do not want to receive any additional events after Stop but do not want to wait for the Stopped event.

The following diagram shows how the PnpObjectWatcher transitions between the states represented by DeviceWatcherStatus enumeration.

Occurs when a PnpObject is added to the collection enumerated by the PnpObjectWatcher.

public : event TypedEventHandler Addedpublic event TypedEventHandler AddedPublic Event Added

Attributes

ContractVersionAttribute DualApiPartitionAttribute MarshalingBehaviorAttribute

Occurs when the enumeration of Pnp device objects has been completed.

public : event TypedEventHandler EnumerationCompletedpublic event TypedEventHandler EnumerationCompletedPublic Event EnumerationCompleted

Attributes

ContractVersionAttribute DualApiPartitionAttribute MarshalingBehaviorAttribute

Occurs when a PnpObject is removed from the collection enumerated by the PnpObjectWatcher.

public : event TypedEventHandler Removedpublic event TypedEventHandler RemovedPublic Event Removed

Attributes

ContractVersionAttribute DualApiPartitionAttribute MarshalingBehaviorAttribute

Occurs when the PnpObjectWatcher has stopped monitoring changes to the collection of Pnp device objects.

public : event TypedEventHandler Stoppedpublic event TypedEventHandler StoppedPublic Event Stopped

Attributes

ContractVersionAttribute DualApiPartitionAttribute MarshalingBehaviorAttribute

Occurs when the properties of a PnpObject in the collection enumerated by the PnpObjectWatcher are updated.

public : event TypedEventHandler Updatedpublic event TypedEventHandler UpdatedPublic Event Updated

Attributes

ContractVersionAttribute DualApiPartitionAttribute MarshalingBehaviorAttribute