StorageItemQueryResult StorageItemQueryResult StorageItemQueryResult StorageItemQueryResult Class

Provides access to the results of a query that lists all items including files and folders (or file groups) in the folder being queried (which is represented by a StorageFolder ). You can use StorageItemQueryResult to enumerate the files and folders in that StorageFolder.

Syntax

Declaration

public sealed class StorageItemQueryResultpublic sealed class StorageItemQueryResultPublic NotInheritable Class StorageItemQueryResultpublic sealed class StorageItemQueryResult

Remarks

Note

Although it's not attributed with marshalling_behavior(agile), this class can be treated as agile. For more info, see Threading and Marshaling (C++/CX).

You can get a StorageItemQueryResult object by calling the following methods from a StorageFolder or a FolderInformation object:

Properties summary

Gets the folder originally used to create the StorageItemQueryResult object. This folder represents the scope of the query.

Methods summary

Modifies query results based on new QueryOptions.

Retrieves the index of the item from the query results that most closely matches the specified property value. The property that is matched is determined by the first SortEntry of the SortOrder list.

Retrieves the query options used to determine query results.

Retrieves the number of items in the set of query results.

Retrieves a list of all the items (files and folders) in the query results set.

Retrieves a list of items (files and folders) in a specified range.

Events summary

Fires when an item is added to, deleted from, or modified in the folder being queried. This event only fires after GetItemsAsync() has been called at least once.

Fires when the query options change.

Properties

  • Folder
    Folder
    Folder
    Folder

    Gets the folder originally used to create the StorageItemQueryResult object. This folder represents the scope of the query.

    public StorageFolder Folder { get; }public StorageFolder Folder { get; }Public ReadOnly Property Folder As StorageFolderpublic StorageFolder Folder { get; }

    Property Value

Methods

  • ApplyNewQueryOptions(QueryOptions)
    ApplyNewQueryOptions(QueryOptions)
    ApplyNewQueryOptions(QueryOptions)
    ApplyNewQueryOptions(QueryOptions)

    Modifies query results based on new QueryOptions.

    public void ApplyNewQueryOptions(QueryOptions newQueryOptions)public void ApplyNewQueryOptions(QueryOptions newQueryOptions)Public Function ApplyNewQueryOptions(newQueryOptions As QueryOptions) As voidpublic void ApplyNewQueryOptions(QueryOptions newQueryOptions)

    Parameters

    Remarks

    This method causes the OptionsChanged event to fire.

    When this method returns, subsequent calls to GetItemsAsync() or GetItemCountAsync() will reflect the results of the new QueryOptions.

  • FindStartIndexAsync(Object)
    FindStartIndexAsync(Object)
    FindStartIndexAsync(Object)
    FindStartIndexAsync(Object)

    Retrieves the index of the item from the query results that most closely matches the specified property value. The property that is matched is determined by the first SortEntry of the SortOrder list.

    public IAsyncOperation<uint> FindStartIndexAsync(Object value)public IAsyncOperation<uint> FindStartIndexAsync(Object value)Public Function FindStartIndexAsync(value As Object) As IAsyncOperation( Of uint )public IAsyncOperation<uint> FindStartIndexAsync(Object value)

    Parameters

    • value
      System.Object
      System.Object
      System.Object
      System.Object

      The property value to match when searching the query results. The property to that is used to match this value is the property in the first SortEntry of the SortOrder list.

    Returns

    • When this method completes successfully it returns the index of the matched item in the query results.

    Remarks

    Examples

    This example shows how to find the first item that has an album title that begins with an "R" in a set of query results that contains albums sorted by title.

    
    QueryOptions queryOptions = new QueryOptions();
    queryOptions.FolderDepth = FolderDepth.Deep;
    queryOptions.IndexerOption = IndexerOption.OnlyUseIndexer;
    SortEntry album = new SortEntry();
    album.AscendingOrder = true;
    album.PropertyName = "System.Music.AlbumTitle";
    queryOptions.SortOrder.Add(album);
    
    StorageFolderQueryResult queryResult = musicFolder.CreateItemQueryWithOptions(queryOptions);
    var firstIndex = await queryResult.FindStartIndexAsync("R");
    
    var queryOptions = new Windows.Storage.Search.QueryOptions();
    queryOptions.folderDepth = Windows.Storage.Search.FolderDepth.deep;
    queryOptions.indexerOption = Windows.Storage.Search.IndexerOptions.onlyUseIndexer;
    queryOptions.sortOrder.append({
     ascendingOrder: true,
     propertyName: "System.Music.AlbumTitle"
    });
    
    var queryResult = Windows.Storage.KnownFolders.picturesLibrary.createFolderQueryWithOptions(queryOptions);
    var firstIndex = queryResult.findStartIndexAsync("R");
    
  • GetCurrentQueryOptions()
    GetCurrentQueryOptions()
    GetCurrentQueryOptions()
    GetCurrentQueryOptions()

    Retrieves the query options used to determine query results.

    public QueryOptions GetCurrentQueryOptions()public QueryOptions GetCurrentQueryOptions()Public Function GetCurrentQueryOptions() As QueryOptionspublic QueryOptions GetCurrentQueryOptions()

    Returns

  • GetItemCountAsync()
    GetItemCountAsync()
    GetItemCountAsync()
    GetItemCountAsync()

    Retrieves the number of items in the set of query results.

    public IAsyncOperation<uint> GetItemCountAsync()public IAsyncOperation<uint> GetItemCountAsync()Public Function GetItemCountAsync() As IAsyncOperation( Of uint )public IAsyncOperation<uint> GetItemCountAsync()

    Returns

    • When this method completes successfully, it returns the number of items in the location that match the query.

  • GetItemsAsync()
    GetItemsAsync()
    GetItemsAsync()
    GetItemsAsync()

    Retrieves a list of all the items (files and folders) in the query results set.

    public IAsyncOperation<IVectorView<IStorageItem>> GetItemsAsync()public IAsyncOperation<IVectorView<IStorageItem>> GetItemsAsync()Public Function GetItemsAsync() As IAsyncOperation( Of IVectorViewIStorageItem )public IAsyncOperation<IVectorView<IStorageItem>> GetItemsAsync()

    Returns

    • When this method completes successfully, it returns a list (type IVectorView<T> ) of items. Each item is the IStorageItem type and represents a file, folder, or file group.

      In this list, files are represented by StorageFile objects, and folders or file groups are represented by StorageFolder objects.

  • GetItemsAsync(UInt32, UInt32)
    GetItemsAsync(UInt32, UInt32)
    GetItemsAsync(UInt32, UInt32)
    GetItemsAsync(UInt32, UInt32)

    Retrieves a list of items (files and folders) in a specified range.

    public IAsyncOperation<IVectorView<IStorageItem>> GetItemsAsync(UInt32 startIndex, UInt32 maxNumberOfItems)public IAsyncOperation<IVectorView<IStorageItem>> GetItemsAsync(UInt32 startIndex, UInt32 maxNumberOfItems)Public Function GetItemsAsync(startIndex As UInt32, maxNumberOfItems As UInt32) As IAsyncOperation( Of IVectorViewIStorageItem )public IAsyncOperation<IVectorView<IStorageItem>> GetItemsAsync(UInt32 startIndex, UInt32 maxNumberOfItems)

    Parameters

    • startIndex
      System.UInt32
      System.UInt32
      System.UInt32
      System.UInt32

      The zero-based index of the first item to retrieve. This parameter defaults to 0.

    • maxNumberOfItems
      System.UInt32
      System.UInt32
      System.UInt32
      System.UInt32

      The maximum number of items to retrieve. Use -1 to retrieve all items. If the range contains fewer items than the max number, all items in the range are returned.

    Returns

    • When this method completes successfully, it returns a list (type IVectorView<T> ) of items. Each item is the IStorageItem type and represents a file, folder, or file group.

      In this list, files are represented by StorageFile objects, and folders or file groups are represented by StorageFolder objects.

    Remarks

    You can use the IsOfType(StorageItemTypes) method on both types of storage objects to find out whether an item is a StorageFile or StorageFolder object.

    For C#/C++/VB: After you know whether the item is a StorageFile or StorageFolder, you can then cast the item to the appropriate type in order to access properties and methods specific to that object.

    Use this overload to improve system performance by presenting a virtualized view of the query results that includes only the necessary subset of folders. For example, if your app displays many items in a gallery you could use this range to retrieve only the items that are currently visible to the user.

Events

  • ContentsChanged
    ContentsChanged
    ContentsChanged
    ContentsChanged

    Fires when an item is added to, deleted from, or modified in the folder being queried. This event only fires after GetItemsAsync() has been called at least once.

    public event TypedEventHandler ContentsChangedpublic event TypedEventHandler ContentsChangedPublic Event ContentsChangedpublic event TypedEventHandler ContentsChanged

    Remarks

    If you register a handler for this event, keep that handler registered while you suspend your app (in response to oncheckpoint or Suspending ). Your app will not receive ContentsChanged events while it is suspended and when your app resumes it will receive a single event that aggregates all of the changes if any occurred.

    Additionally, keep in mind that registering and removing event handlers are synchronous operations and might cause your app to stop responding briefly if you execute them on your app's UI thread. Wherever possible, use a thread other than your app's UI thread to register and unregister these event handlers.

  • OptionsChanged
    OptionsChanged
    OptionsChanged
    OptionsChanged

    Fires when the query options change.

    public event TypedEventHandler OptionsChangedpublic event TypedEventHandler OptionsChangedPublic Event OptionsChangedpublic event TypedEventHandler OptionsChanged

Device family

Windows 10 (introduced v10.0.10240.0)

API contract

Windows.Foundation.UniversalApiContract (introduced v1)

Attributes

Windows.Foundation.Metadata.ContractVersionAttribute

Details

Assembly

Windows.Storage.Search.dll