Cannot display image which retireved from Local Folder

Question

I have some images files(.png) stored in LocalFolder. I want to retrieve it and display in Image control.

The code below has no compiled error but it did not work. Can anyone point out what wrong with my code. Both are not working. Method (2) : Bitmapimage is null ? event there is data in RandomAccess

Method 1:

private async void LoadAndDisplayImgFile(int ProdId)
         {
             string strFilenm = "S-" + ProdId.ToString() + ".png";

            var folder_path = System.IO.Path.Combine(Windows.Storage.ApplicationData.Current.LocalFolder.Path, "ImgProd");

            StorageFolder folder = await StorageFolder.GetFolderFromPathAsync(folder_path);

            StorageFile storagefile = await folder.GetFileAsync(strFilenm);

            StorageFile jpgFile = await folder.GetFileAsync(strFilenm);

            DisplayImg(jpgFile);
        
        }

   private async void DisplayImg(StorageFile ImgFile)
         {

             IRandomAccessStream fileStream = await ImgFile.OpenAsync(FileAccessMode.Read);         

            var reader = new Windows.Storage.Streams.DataReader(fileStream.GetInputStreamAt(0));

            await reader.LoadAsync((uint)fileStream.Size);
 
             byte[] pixels = new byte[fileStream.Size];

            reader.ReadBytes(pixels);

            InMemoryRandomAccessStream ms = new InMemoryRandomAccessStream();

            DataWriter writer = new DataWriter(ms.GetOutputStreamAt(0));

            writer.WriteBytes(pixels as byte[]);
     
             writer.StoreAsync().GetResults();

            BitmapImage image = new BitmapImage();

            image.SetSource(ms);
          
        
            await this.Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () =>
             {
                 Image1.Source = image;

            });              
         }

Method 2:

 private async void LoadAndDisplayImgFile(int ProdId)
 {
    string strFilenm = "S-" + ProdId.ToString() + ".png";

  var folder_path = System.IO.Path.Combine(Windows.Storage.ApplicationData.Current.LocalFolder.Path, "ImgProd");

 StorageFolder folder = await StorageFolder.GetFolderFromPathAsync(folder_path);

 StorageFile jpgFile = await folder.GetFileAsync(strFilenm);
  
 IRandomAccessStream fileStream = await jpgFile.OpenAsync(Windows.Storage.FileAccessMode.Read);

 fileStream.Seek(0);
              
 BitmapImage bi = new BitmapImage();  
 bi.SetSource(fileStream);
 Image1.Source = bi;                  

             
 }

Answer 1

There is a simple way to do this.

       private void SetImageFromInstalledLocation()
       {
           BitmapImage image = new BitmapImage(new Uri("ms-appx:///Assets/2.png"));
           img1.Source = image; 
       }


       private void SetImageFromIsolateStorage()
       {
           BitmapImage image = new BitmapImage(new Uri("ms-appdata:///local/Images/S1.png"));
           img2.Source = image; 
       }

You can download my sample project form here.

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Answer 2

The following implementation of the LoadAndDisplayImgFile works when called with ProdId = 1 provided that there is a valid .png file named "S-1.png" in the local folder:

private async void LoadAndDisplayImgFile(int ProdId)
        {
            string strFilenm = "S-" + ProdId.ToString() + ".png";

            var folder_path = System.IO.Path.Combine(Windows.Storage.ApplicationData.Current.LocalFolder.Path, "ImgProd");

            StorageFolder folder = await StorageFolder.GetFolderFromPathAsync(folder_path);

            StorageFile jpgFile = await folder.GetFileAsync(strFilenm);

            BitmapImage bitmapImage = new BitmapImage();
            FileRandomAccessStream stream = await jpgFile.OpenAsync(FileAccessMode.Read) as FileRandomAccessStream;
            bitmapImage.SetSource(stream);
            Image1.Source = bitmapImage;
        }

<Image x:Name="Image1"/>

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Answer 3

Hi Magnus,

Your code work.

However, I don't seems to understand when I do some break point in the code at 3 and 5. I step thru in VS.

stream show this data :

CanRead  true
CanWrite false
position 0
Size     389801

bitmapImage Show this:

CreateOption      None
DecodePexelHeight 0
DecodePixelType   0
UriSource         null

If bitmapImage is null or not base on the above? But in the end I got the image displayed.

Thanks

  {

1) BitmapImage bitmapImage = new BitmapImage();
           
2) FileRandomAccessStream stream = await jpgFile.OpenAsync(FileAccessMode.Read) as FileRandomAccessStream;
           
3) bitmapImage.SetSource(stream);
           
4) Image1.Source = bitmapImage;

5) }