SetPropertyPrefetch() 공개 메소드

public SetPropertyPrefetch ( [ options, [ propertiesToRetrieve ) : void
options [
propertiesToRetrieve [
리턴 void
        private async void Find_Click(object sender, RoutedEventArgs e)
        {
            ContentTextOutput.Text = "";
            List <string> propertyNames = new List <string>();

            propertyNames.Add("System.FileName");
            var queryOptions = new Windows.Storage.Search.QueryOptions();

            queryOptions.IndexerOption    = Windows.Storage.Search.IndexerOption.OnlyUseIndexer;
            queryOptions.UserSearchFilter = FindQueryText.Text;
            queryOptions.SetPropertyPrefetch(Windows.Storage.FileProperties.PropertyPrefetchOptions.DocumentProperties, propertyNames);

            // Query the Pictures library.
            StorageFileQueryResult      queryResult = Windows.Storage.KnownFolders.PicturesLibrary.CreateFileQueryWithOptions(queryOptions);
            IReadOnlyList <StorageFile> files       = await queryResult.GetFilesAsync();

            foreach (StorageFile file in files)
            {
                IDictionary <String, IReadOnlyList <Windows.Data.Text.TextSegment> > fileRangeProperties = queryResult.GetMatchingPropertiesWithRanges(file);
                if (fileRangeProperties.ContainsKey("System.FileName"))
                {
                    IReadOnlyList <Windows.Data.Text.TextSegment> ranges;
                    fileRangeProperties.TryGetValue("System.FileName", out ranges);
                    rootPage.HighlightRanges(ContentTextOutput, file.DisplayName, ranges);
                }
                // Note: You can continue looking for other properties you would like to highlight on the file here.
            }
            if (files.Count == 0)
            {
                ContentTextOutput.Text = "There were no matching files in your Pictures Library";
            }
        }
        private async void Find_Click(object sender, RoutedEventArgs e)
        {
            ContentTextOutput.Text = "";
            List<string> propertyNames = new List<string>();
            propertyNames.Add("System.FileName");
            var queryOptions = new Windows.Storage.Search.QueryOptions();
            queryOptions.IndexerOption = Windows.Storage.Search.IndexerOption.OnlyUseIndexer;
            queryOptions.UserSearchFilter = FindQueryText.Text;
            queryOptions.SetPropertyPrefetch(Windows.Storage.FileProperties.PropertyPrefetchOptions.DocumentProperties, propertyNames);

            // Query the Pictures library.
            StorageFileQueryResult queryResult = Windows.Storage.KnownFolders.PicturesLibrary.CreateFileQueryWithOptions(queryOptions);
            IReadOnlyList<StorageFile> files = await queryResult.GetFilesAsync();
            foreach (StorageFile file in files)
            {
                IDictionary<String, IReadOnlyList<Windows.Data.Text.TextSegment>> fileRangeProperties = queryResult.GetMatchingPropertiesWithRanges(file);
                if (fileRangeProperties.ContainsKey("System.FileName"))
                {
                    IReadOnlyList<Windows.Data.Text.TextSegment> ranges;
                    fileRangeProperties.TryGetValue("System.FileName", out ranges);
                    rootPage.HighlightRanges(ContentTextOutput, file.DisplayName, ranges);
                }
                // Note: You can continue looking for other properties you would like to highlight on the file here.
            }
            if (files.Count == 0)
            {
                ContentTextOutput.Text = "There were no matching files in your Pictures Library";
            }
        }
        private async void GetFilesButton_Click(object sender, RoutedEventArgs e)
        {
            // Reset output.
            OutputPanel.Children.Clear();

            // Set up file type filter.
            List<string> fileTypeFilter = new List<string>();
            fileTypeFilter.Add(".jpg");
            fileTypeFilter.Add(".png");
            fileTypeFilter.Add(".bmp");
            fileTypeFilter.Add(".gif");

            // Create query options.
            var queryOptions = new QueryOptions(CommonFileQuery.OrderByName, fileTypeFilter);

            // Set up property prefetch - use the PropertyPrefetchOptions for top-level properties
            // and a list for additional properties.
            List<string> propertyNames = new List<string>();
            propertyNames.Add(CopyrightProperty);
            propertyNames.Add(ColorSpaceProperty);
            queryOptions.SetPropertyPrefetch(PropertyPrefetchOptions.ImageProperties, propertyNames);

            // Set up thumbnail prefetch if needed, e.g. when creating a picture gallery view.
            /*
            const uint requestedSize = 190;
            const ThumbnailMode thumbnailMode = ThumbnailMode.PicturesView;
            const ThumbnailOptions thumbnailOptions = ThumbnailOptions.UseCurrentScale;
            queryOptions.SetThumbnailPrefetch(thumbnailMode, requestedSize, thumbnailOptions);
            */

            // Set up the query and retrieve files.
            StorageFolder picturesFolder = await KnownFolders.GetFolderForUserAsync(null /* current user */, KnownFolderId.PicturesLibrary);
            var query = picturesFolder.CreateFileQueryWithOptions(queryOptions);
            IReadOnlyList<StorageFile> fileList = await query.GetFilesAsync();
            foreach (StorageFile file in fileList)
            {
                OutputPanel.Children.Add(CreateHeaderTextBlock(file.Name));

                // GetImagePropertiesAsync will return synchronously when prefetching has been able to
                // retrieve the properties in advance.
                var properties = await file.Properties.GetImagePropertiesAsync();
                OutputPanel.Children.Add(CreateLineItemTextBlock("Dimensions: " + properties.Width + "x" + properties.Height));

                // Similarly, extra properties are retrieved asynchronously but may
                // return immediately when prefetching has fulfilled its task.
                IDictionary<string, object> extraProperties = await file.Properties.RetrievePropertiesAsync(propertyNames);
                var propValue = extraProperties[CopyrightProperty];
                OutputPanel.Children.Add(CreateLineItemTextBlock("Copyright: " + GetPropertyDisplayValue(propValue)));
                propValue = extraProperties[ColorSpaceProperty];
                OutputPanel.Children.Add(CreateLineItemTextBlock("Color space: " + GetPropertyDisplayValue(propValue)));

                // Thumbnails can also be retrieved and used.
                // var thumbnail = await file.GetThumbnailAsync(thumbnailMode, requestedSize, thumbnailOptions);
            }
        }