StorageLibraryChangeTracker.Disable 方法
定义
重要
一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。 对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。
禁用 StorageFolder 或 StorageLibrary 的更改跟踪。
public:
virtual void Disable() = Disable;void Disable();public void Disable();function disable()Public Sub Disable ()Windows 要求
| 设备系列 |
Windows 10, version 2104 (在 10.0.20348.0 中引入)
|
| API contract |
Windows.Foundation.UniversalApiContract (在 v12.0 中引入)
|
示例
// applications are expected to persist the previous value
UINT64 appsLastPersistedChangeId = StorageLibraryLastChangeId::Unknown();
StorageFolder folder = StorageFolder::GetFolderFromPathAsync(L"my folder path").get();
StorageLibraryChangeTracker tracker = folder.TryGetChangeTracker();
if (tracker != nullptr)
{
StorageLibraryChangeTrackerOptions ops;
ops.TrackChangeDetails(false);
tracker.Enable(ops);
StorageLibraryChangeReader reader = tracker.GetChangeReader();
if (reader != nullptr)
{
UINT32 changeId = reader.GetLastChangeId();
if ((changeId == StorageLibraryLastChangeId::Unknown())
{
ScanFolderSlow();
}
else if (changeId == 0)
{
// no changes in the storage folder yet, OR nothing has changed
ProcessNormalApplicationStartup();
}
else if (changeId != appsLastPersistedChangeId)
{
// There have been new changes since we’ve last ran, process them
appsLastPersistedChangeId = changeId;
ScanFolderForChanges();
}
else
{
// changeId and our last persisted change id match, also normal application startup
ProcessNormalApplicationStartup();
}
}
}
注解
如果调用应用程序尚未在 StorageFolder/StorageLibrary 上调用 Enable，此方法将不执行任何操作。