C# Converting BitmapSource to BitmapImage

Question

I am trying to write a function that converts a BitmapSource to a BitmapImage. The only way I could find to do this was to create a temporary bmp file write and read from the file to create a new BitmapImage. This works fine until you try to delete the file or re-use the function. There are some file handling errors where the file will still be in use until the BitmapImage is freed.

1 - Is there a better way of converting BitmapSource to BitmapImages?

2 - What can I do to return the BitmapImage without freeing it?

public BitmapImage ConvertSourceToBitMapImage(BitmapSource bitmapSource)
{
    BitmapImage bmi = null;
    try
    {
        string filePath = @"C:\GitRepository\ReceiptAPP\ReceiptApplication\bin\Debug\testing.bmp";
        using (var fileStream = new FileStream(filePath, FileMode.Create))
        {
            BitmapEncoder encoder = new BmpBitmapEncoder();
            encoder.Frames.Add(BitmapFrame.Create(bitmapSource));
            encoder.Save(fileStream);
            fileStream.Close();
        }
        Uri path = new Uri(filePath);
        bmi = new BitmapImage(path);
        File.Delete(filePath);
    }
    catch(Exception ex)
    {
    }
    return bmi;
}

Answer 1

Encoding to and decoding from a MemoryStream is a lot more efficient than a file.

Note however that there is no use case for a conversion from BitmapSource to BitmapImage. A BitmapSource can directly be used as the Source of an Image element or as the ImageSource of an ImageBrush. You never explicitly need a BitmapImage.

public static BitmapImage ConvertBitmapSourceToBitmapImage(
    BitmapSource bitmapSource)
{
    // before encoding/decoding, check if bitmapSource is already a BitmapImage

    if (!(bitmapSource is BitmapImage bitmapImage))
    {
        bitmapImage = new BitmapImage();

        BmpBitmapEncoder encoder = new BmpBitmapEncoder();
        encoder.Frames.Add(BitmapFrame.Create(bitmapSource));

        using (MemoryStream memoryStream = new MemoryStream())
        {
            encoder.Save(memoryStream);
            memoryStream.Position = 0;

            bitmapImage.BeginInit();
            bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
            bitmapImage.StreamSource = memoryStream;
            bitmapImage.EndInit();
        }
    }

    return bitmapImage;
}