PhoneLineWatcher Class

Definition

public ref class PhoneLineWatcher sealed

/// [Windows.Foundation.Metadata.ContractVersion(Windows.ApplicationModel.Calls.CallsPhoneContract, 65536)]
/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
/// [Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
class PhoneLineWatcher final

[Windows.Foundation.Metadata.ContractVersion(typeof(Windows.ApplicationModel.Calls.CallsPhoneContract), 65536)]
[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
[Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
public sealed class PhoneLineWatcher

Public NotInheritable Class PhoneLineWatcher

Inheritance

Object Platform::Object IInspectable PhoneLineWatcher

Attributes

ContractVersionAttribute MarshalingBehaviorAttribute ThreadingAttribute

Windows requirements

Remarks

A phone line is a line that a user can use to either receive inbound or place outbound phone calls. A single device can have multiple lines. For example, the system creates a separate line specifically for VoIP applications that enables initiating an outbound call.

The system automatically detects the available lines on boot and then dynamically detects lines as lines are created or changed. The PhoneLineWatcher class provides a mechanism for applications to receive events as new phone lines are detected and react to the changes.

This class implements the watcher pattern.

You can retrieve an instance of this class by calling RequestLineWatcher.

The following example shows how to enumerate through all the current phone lines.

private async Task<Dictionary<Guid, PhoneLine>> GetPhoneLinesAsync()
{
    PhoneCallStore store = await PhoneCallManager.RequestStoreAsync();

    // Start the PhoneLineWatcher
    var watcher = store.RequestLineWatcher();
    var phoneLines = new List<PhoneLine>();
    var lineEnumerationCompletion = new TaskCompletionSource<bool>();
    watcher.LineAdded += async (o, args) => { var line = await PhoneLine.FromIdAsync(args.LineId); phoneLines.Add(line); };
    watcher.Stopped += (o, args) => lineEnumerationCompletion.TrySetResult(false);
    watcher.EnumerationCompleted += (o, args) => lineEnumerationCompletion.TrySetResult(true);
    watcher.Start();

    // Wait for enumeration completion
    if (!await lineEnumerationCompletion.Task)
    {
        throw new Exception("Phone Line Enumeration failed");
    }

    watcher.Stop();

    Dictionary<Guid, PhoneLine> returnedLines = new Dictionary<Guid, PhoneLine>();

    foreach (PhoneLine phoneLine in phoneLines)
    {
        if (phoneLine != null && phoneLine.Transport == PhoneLineTransport.Cellular)
        {
            returnedLines.Add(phoneLine.Id, phoneLine);
        }
    }

    return returnedLines;
}

Properties

Methods

Events

Applies to