How to save image form imagesource

Question

I have Image control ,I want so save image to Local Data from Image Control source

        public static async Task SaveImages(BitmapSource images)
        {
var folder = ApplicationData.Current.LocalFolder;
            try
            {
                StorageFile file = await folder.CreateFileAsync("111.png", CreationCollisionOption.ReplaceExisting);
                using (var readStream = await file.OpenAsync(FileAccessMode.ReadWrite))
                { 
                    var outPutStream = readStream.GetOutputStreamAt(0);
                    WriteableBitmap wb = new WriteableBitmap(images.PixelWidth, images.PixelHeight);
                    DataWriter dw = new DataWriter(outPutStream);                    
                    dw.WriteBytes(wb.PixelBuffer.ToArray());
                    await dw.StoreAsync();
                    await outPutStream.FlushAsync();
                }
            }
            catch (Exception ex)
            {
                throw ex;
            }
}

that's code work but  I can't open this images file (111.png)  from windows picture manger

var bytes=wb.PixelBuffer.ToArray();

and then I debug found bytes  item value is 0

Answer 1

You are storing out raw, uninitialized bytes from your WriteableBitmap.

You will need to use a WriteableBitmap which has data in it and then convert to PNG format with a BitmapEncoder.

I believe the imaging sample demonstrates how to do this.

--Rob

Answer 2

I see the imaging sample through FilePicker get the stream 

 I set  Uri to image control  ,So I use the HttpClient download the image get the stream and convert it ,But in this way its very complex

Is there any simple solution convert BitmapSource to IRandomAccessStream tks

Answer 3

There is no way to convert a BitmapSource to an IRandomAccessStream. You need to either keep the original source URL or store the bits in a WriteableBitmap.

To convert the pixels from their raw format in the WriteableBitmap into a storage format such as PNG you would use a BitmapEncoder.

--Rob