Aracılığıyla paylaş


StorageFolder.CreateItemQuery Method

Definition

Gets a query result object that contains the files and subfolders in the current folder.

public:
 virtual StorageItemQueryResult ^ CreateItemQuery() = CreateItemQuery;
StorageItemQueryResult CreateItemQuery();
public StorageItemQueryResult CreateItemQuery();
function createItemQuery()
Public Function CreateItemQuery () As StorageItemQueryResult

Returns

A query result object. Call the GetItemsAsync method of the query result to get the files and subfolders in the current folder. This method returns a list of type IReadOnlyList<IStorageItem>. Each file or folder is represented by an item of type IStorageItem.

To work with the returned items, call the IsOfType method of the IStorageItem interface to determine whether each item is a file or a folder. Then cast the item to a StorageFolder or StorageFile.

Implements

Exceptions

You don't have permission to access the contents of the current folder.

Examples

The following example shows how to get the files and subfolders in the current folder by calling the CreateItemQuery() method.

using Windows.Storage;
using Windows.Storage.Search;
using System.Threading.Tasks;
using System.Diagnostics; // For writing results to the Output window.

// Get the app's installation folder.
StorageFolder appFolder = Windows.ApplicationModel.Package.Current.InstalledLocation;

// Get the items in the current folder.
StorageItemQueryResult itemsInFolder = appFolder.CreateItemQuery();

// Iterate over the results and print the list of items
// to the Visual Studio Output window.
foreach (IStorageItem item in await itemsInFolder.GetItemsAsync())
{
    if(item.IsOfType(StorageItemTypes.Folder))
        Debug.WriteLine("Folder: " + item.Name);
    else
        Debug.WriteLine("File: " + item.Name + ", " + item.DateCreated);
}
IAsyncAction MainPage::ExampleCoroutineAsync()
{
    // Get the app's installation folder.
    Windows::Storage::StorageFolder appFolder{ Windows::ApplicationModel::Package::Current().InstalledLocation() };

    Windows::Storage::Search::StorageItemQueryResult results{ appFolder.CreateItemQuery() };

    // Get the items in the current folder.
    Windows::Foundation::Collections::IVectorView<Windows::Storage::IStorageItem> itemsInFolder{
        co_await results.GetItemsAsync() };

    // Iterate over the results, and print the list of items to the Visual Studio output window.
    for (IStorageItem const& itemInFolder : itemsInFolder)
    {
        std::wstringstream stringstream;

        if (itemInFolder.IsOfType(Windows::Storage::StorageItemTypes::File))
        {
            stringstream << L"File: ";
        }
        else
        {
            stringstream << L"Folder: ";
        }

        stringstream << itemInFolder.Name().c_str() << std::endl;
        ::OutputDebugString(stringstream.str().c_str());
    }
}
// Get the app's installation folder
StorageFolder^ appFolder = Windows::ApplicationModel::Package::Current->InstalledLocation;

StorageItemQueryResult^ results = appFolder->CreateItemQuery();

// Get the items in the current folder; 
create_task(results->GetItemsAsync()).then([=](IVectorView<IStorageItem^>^ itemsInFolder) {

 //Iterate over the results and print the list of items
    // to the visual studio output window
    for (auto it = itemsInFolder->First(); it->HasCurrent; it->MoveNext())
    {
        IStorageItem^ item = it->Current;
        if (item->IsOfType(StorageItemTypes::File))
        {
            String^ output = "File: " + item->Name + "\n";
            OutputDebugString(output->Begin());
        }
        else
        {
            String^ output = "Folder: " + item->Name + "\n";
            OutputDebugString(output->Begin());
        }        
    }
});

Remarks

This query is a shallow query that returns only items in the current folder. For a list of methods that identifies shallow queries and deep queries, see the Remarks in the topic GetItemsAsync.

You can also get a list of items in the current folder asynchronously by calling one of the GetItemsAsync methods.

To specify additional query options, call the CreateItemQueryWithOptions method.

Applies to