StorageLibraryChangeTrackerTrigger Kelas

Referensi

Definisi

Ruang nama:: Windows.ApplicationModel.Background

Penting

Beberapa informasi terkait produk prarilis yang dapat diubah secara signifikan sebelum dirilis. Microsoft tidak memberikan jaminan, tersirat maupun tersurat, sehubungan dengan informasi yang diberikan di sini.

Edit

Mewakili perubahan file dalam StorageFolder yang memicu tugas latar belakang untuk dijalankan.

public ref class StorageLibraryChangeTrackerTrigger sealed : IBackgroundTrigger

/// [Windows.Foundation.Metadata.Activatable(Windows.ApplicationModel.Background.IStorageLibraryChangeTrackerTriggerFactory, 393216, "Windows.Foundation.UniversalApiContract")]
/// [Windows.Foundation.Metadata.ContractVersion(Windows.Foundation.UniversalApiContract, 393216)]
/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
/// [Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
class StorageLibraryChangeTrackerTrigger final : IBackgroundTrigger

[Windows.Foundation.Metadata.Activatable(typeof(Windows.ApplicationModel.Background.IStorageLibraryChangeTrackerTriggerFactory), 393216, "Windows.Foundation.UniversalApiContract")]
[Windows.Foundation.Metadata.ContractVersion(typeof(Windows.Foundation.UniversalApiContract), 393216)]
[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
[Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
public sealed class StorageLibraryChangeTrackerTrigger : IBackgroundTrigger

function StorageLibraryChangeTrackerTrigger(tracker)

Public NotInheritable Class StorageLibraryChangeTrackerTrigger
Implements IBackgroundTrigger

Warisan: Object Platform::Object IInspectable StorageLibraryChangeTrackerTrigger

Atribut: ActivatableAttribute ContractVersionAttribute MarshalingBehaviorAttribute ThreadingAttribute

Penerapan: IBackgroundTrigger

Persyaratan Windows

Rangkaian perangkat	Windows 10, version 1803 (diperkenalkan dalam 10.0.17134.0)
API contract	Windows.Foundation.UniversalApiContract (diperkenalkan dalam v6.0)

Contoh

Contoh berikut menunjukkan cara membuat dan mendaftarkan pemicu perubahan pustaka penyimpanan untuk folder yang ditentukan.

private async Task<bool> RegisterBackgroundTask(StorageFolder folder)
{
    StorageLibraryChangeTracker tracker = folder.TryGetChangeTracker();
    if (tracker != null)
    {
        tracker.Enable();

        StorageLibraryChangeTrackerTrigger trigger = new StorageLibraryChangeTrackerTrigger(tracker);

        string name = "StorageLibraryChangeTrackerTask"; // a friendly task name
        string taskEntryPoint = "Tasks.StorageLibraryChangeTrackerTask";

        var access = await BackgroundExecutionManager.RequestAccessAsync(); // to register background tasks, you must first call RequestAccessAsync()

        BackgroundTaskBuilder builder = new BackgroundTaskBuilder();
        builder.Name = name;
        builder.TaskEntryPoint = taskEntryPoint;
        builder.SetTrigger(trigger);
        BackgroundTaskRegistration task = builder.Register();

        return true;
    }

    // Not getting a tracker means we don't have access to the folder or it’s not a physical folder
    return false;
}

Keterangan

Tugas latar belakang harus dideklarasikan dalam manifes sebelum pendaftaran berhasil.

Konstruktor

StorageLibraryChangeTrackerTrigger(StorageLibraryChangeTracker)

Menginisialisasi instans StorageLibraryChangeTrackerTrigger baru.

Berlaku untuk

Bagikan melalui