<UserControl

    x:Class="UserControls.UcFile"

    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

    xmlns:local="using:UserControls"

    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"

    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"

    mc:Ignorable="d"

    d:DesignHeight="100"

    d:DesignWidth="100" Loading="UserControl_Loading" Loaded="UserControl_Loaded">

    <Grid Width="100" Height="100" BorderBrush="Red" BorderThickness="1">

        <Image x:Name="tnImage" Stretch="UniformToFill" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" ></Image>

    </Grid>

</UserControl>

<Page

    x:Class="Smartphone_Imagefolder_lesen.MainPage"

    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

    xmlns:local="using:Smartphone_Imagefolder_lesen"

    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"

    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"

    mc:Ignorable="d"

    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">

    <Grid x:Name="MainGrid">

        <Grid.RowDefinitions>

            <RowDefinition Height="50"/>

            <RowDefinition Height="*"/>

        </Grid.RowDefinitions>

        <!-- Row_0 -->

        <Button x:Name="BtnGetDevices" Grid.Row="0" Click="BtnGetDevices_Click" VerticalAlignment="Stretch" >GetFolders</Button>

        <!--/ Row_0 -->

        <!--Image_Grid-->

        <ScrollViewer Grid.Row="1" HorizontalAlignment="Stretch"  VerticalAlignment="Stretch" >

            <GridView x:Name="ctlFiles" HorizontalAlignment="Stretch"  VerticalAlignment="Stretch" 

                      IsMultiSelectCheckBoxEnabled="True"  

                      SelectionMode="Single"                       

                      >

            </GridView>

        </ScrollViewer>

        <!--/ Image_Grid-->

    </Grid>

</Page>

using System;

using Windows.UI.Xaml;          //EventArgs

using Windows.UI.Xaml.Controls; //Page

using Windows.Storage.Pickers;

using Windows.Storage;

using Windows.Storage.AccessCache;

using System.Threading.Tasks;       //Tasks

using System.Linq;                  //FirstOrDefault()

using System.Collections.Generic;   //IReadOnlyList

using UserControls;      //UserControls

namespace Smartphone_Imagefolder_lesen

{

    /// <summary>

    /// An empty page that can be used on its own or navigated to within a Frame.

    /// </summary>

    public sealed partial class MainPage : Page

    {

        public MainPage()

        {

            this.InitializeComponent();

        }

        private async void BtnGetDevices_Click(object sender, RoutedEventArgs e)

        {

            //get camera folder

            StorageFolder cameraFolder = await fxGetCameraFolder();

            if (cameraFolder != null)

            {

                //*read photos+videos

                fxReadFiles_inFolder(cameraFolder);

            }

        }

        public async Task<StorageFolder> fxGetCameraFolder()

        {

            //------------< fxGetCameraFolder()------------

            StorageFolder cameraFolder = null;

            // Get the logical root folder for all external storage devices.

            StorageFolder externalDevices = Windows.Storage.KnownFolders.RemovableDevices;

            // Get the first child folder, which represents the SD card.

            StorageFolder sdCard = (await externalDevices.GetFoldersAsync()).FirstOrDefault();

            if (sdCard != null)

            {

                //-----< Is sdCard >-----

                //*get Smartphone as drive.

                //*smartphone has to be connected and unlocked

                IReadOnlyList<StorageFolder> folderList = await sdCard.GetFoldersAsync();

                //----< @loop: Smartphone folders >----

                //*read folder and search for /DCIM/camera

                foreach (StorageFolder folder in folderList)

                {

                    //---< check smartphone Folder >----

                    String sFoldername = folder.Name;

                    Console.WriteLine( "Smartphone Folder:" + sFoldername);

                    //--< 1.fast: look for /DCIM/camera >--

                    Console.WriteLine("read DCIM");

                    StorageFolder folderDCIM = await folder.GetFolderAsync("DCIM");

                    if (folderDCIM != null)

                    {

                        //-< lookup: camera folder >-

                        Console.WriteLine("read camera folder");

                        cameraFolder = await folderDCIM.GetFolderAsync("camera");

                        if (cameraFolder != null)

                        {

                            break; //*stop searchloop

                        }

                        //-</ lookup: camera folder >-

                    }

                    //--</ 1.fast: look for /DCIM/camera >--

                    //--< 2.slow: loop for /DCIM/camera >--

                    foreach (StorageFolder subFolder in folderList)

                    {

                        if (subFolder.Name == "DCIM")

                        {

                            //--< @Loop: Search camera >--

                            foreach (StorageFolder subSubFolder in folderList)

                            {

                                //---</ check camera folder >----

                                if (folder.Name == "camera")

                                {

                                    //< IsCamera folder >

                                    cameraFolder = folder;

                                    break;

                                    //</ IsCamera folder >

                                }

                                //---< check camera folder >----

                            };

                            //--</ @Loop: Search camera >--

                        }

                        //--</ 2.slow: loop for /DCIM/camera >--

                    }

                    //---</ check smartphone Folder >----

                }

                //----</ @loop: Smartphone folders >----

                //-----</ is sdCard >-----

            }

            return cameraFolder;

            //------------</ fxGetCameraFolder()------------

        }

        public async void fxReadFiles_inFolder(StorageFolder folder)

        {

            //------------< fxReadFiles_inFolder()------------

            ctlFiles.Items.Clear();

            //< check >

            if (folder == null) return;

            //</ check >

            //----< @Loop: Files in Folder >----

            foreach (StorageFile file in await folder.GetFilesAsync())

            {

                //--< File >--

                Console.WriteLine(file.DisplayName);

                GridViewItem item = new GridViewItem();

                item.Margin = new Thickness(1);

                if (file.ContentType.Contains("video") || file.ContentType.Contains("image"))

                {

                    //----< Ist Image >----

                    UcFile ucImage = new UcFile();

                    ucImage.file = file;

                    //item.Content = ucImage;

                    //< anfuegen >

                    item.Content = ucImage;

                    ctlFiles.Items.Add(item);

                    //< anfuegen >

                    //----</ Ist Image >----

                }

                //--</ File >--

            }

            //----</ @Loop: Files in Folder >-----

            //------------</ fxReadFiles_inFolder()------------

        }

    }

}

using Microsoft.UI.Xaml;

using System;

using Windows.UI.Xaml.Media.Imaging;    // Bitmap

using Windows.Storage;                  //Files File.AccessMode

using Windows.Storage.FileProperties;   //Thumbnails

using System.Threading.Tasks;           //Tasks

using Windows.Graphics.Imaging;        //BitmapEncoder

using Windows.UI.Xaml.Controls;

using Windows.UI.Popups;

namespace UserControls

{

    public sealed partial class UcFile : UserControl

    {

        StorageItemThumbnail imgThumbnail;

        StorageFile _file;

        public StorageFile file

        {

            set { _file = value; }

        }

        #region Properties

        //========================< Region: Properties >========================

        //setzen und lesen von Eigenschaften

        //========================</ Region: Properties >========================

        #endregion

        #region UserControl

        //========================< Region: Page >========================

        public UcFile()

        {

            this.InitializeComponent();

        }

        private void UserControl_Loading(Windows.UI.Xaml.FrameworkElement sender, object args)

        {

        }

        private void UserControl_Loaded(object sender, Windows.UI.Xaml.RoutedEventArgs e)

        {

            fl_load_Image();

        }

        //========================< Region: UserControl >========================

        #endregion

        private async void fl_load_Image()

        {

            //------------< fl_load_Image() >------------

            //--< show Image as Thumbnail >--

            try

            {

                imgThumbnail = await _file.GetThumbnailAsync(ThumbnailMode.SingleItem, 100, ThumbnailOptions.ResizeThumbnail);

                //-< show Image  >-

                BitmapImage bitmapImage = new BitmapImage();

                bitmapImage.SetSource(imgThumbnail);

                tnImage.Source = bitmapImage;

                //-</ show Image >-

                //tbxTitle.Text = _file.DisplayName;

            }

            catch (Exception ex)

            {

                //clsDebug.debug_Exception(ex, "Error " + filename_cached);

                //HResult==-2147467261->.wmf

                await new MessageDialog(ex.Message).ShowAsync();

            }

            //--</ show Image as Thumbnail >--

            //------------</ fl_load_Image() >------------

        }

    }

}