/// <summary>
/// Utility method to convert the MIME type enumeration used by this class to the
/// platform's Bitmap Encoder GUID.
/// </summary>
/// <param name="mimeType">MIME type to convert.</param>
/// <returns>GUID that can be used in the bitmap encoder to encode this MIME type.</returns>
public static Guid GetBitmapEncoderIdForMimeType(ImageMimeType mimeType)
{
switch (mimeType)
{
case ImageMimeType.Png:
return(BitmapEncoder.PngEncoderId);
case ImageMimeType.Jpg:
case ImageMimeType.Jpeg:
return(BitmapEncoder.JpegEncoderId);
case ImageMimeType.JpegXr:
return(BitmapEncoder.JpegXREncoderId);
case ImageMimeType.Bmp:
return(BitmapEncoder.BmpEncoderId);
case ImageMimeType.Gif:
return(BitmapEncoder.GifEncoderId);
case ImageMimeType.Tiff:
return(BitmapEncoder.TiffEncoderId);
default:
throw new ArgumentOutOfRangeException();
}
}
/// <summary>
/// Set an image to this class by specifying the WritableBitmap and the target encoding and
/// optionally the DPI to set for the target file (if supported by the target file type).
/// </summary>
/// <remarks>
/// The method takes the bitmap as input and uses the BitmapEncoder to encode
/// the image data into the specified MIME type and file format. The encoded contents are
/// then stored to the payload of the record, the MIME type is set as the type of the record.
/// </remarks>
/// <param name="bmp">Input bitmap to encode and set as payload of this record.</param>
/// <param name="mimeType">MIME type to use for encoding this image.</param>
/// <param name="dpi">Target DPI if supported by the target file / MIME format.</param>
/// <returns>Task to await completion of the asynchronous image encoding.</returns>
public async Task SetImage(WriteableBitmap bmp, ImageMimeType mimeType, double dpi = 96.0)
{
var encoderId = GetBitmapEncoderIdForMimeType(mimeType);
byte[] pixels;
using (var stream = bmp.PixelBuffer.AsStream())
{
pixels = new byte[(uint)stream.Length];
await stream.ReadAsync(pixels, 0, pixels.Length);
}
using (var imgStream = new MemoryStream())
{
var raImgStream = imgStream.AsRandomAccessStream();
var encoder = await BitmapEncoder.CreateAsync(encoderId, raImgStream);
encoder.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Premultiplied,
(uint)bmp.PixelWidth,
(uint)bmp.PixelHeight,
dpi,
dpi,
pixels);
await encoder.FlushAsync();
await raImgStream.FlushAsync();
Payload = imgStream.ToArray();
Type = ImageMimeTypes[mimeType];
}
}
/// <summary>
/// Construct a new MIME / Image record based on a WriteableBitmap.
/// Specify the MIME type and DPI, and the image data is encoded accordingly.
/// </summary>
/// <param name="bmp">Source bitmap to use for conversion.</param>
/// <param name="mimeType">MIME type to specify the target image encoding.</param>
/// <param name="dpi">Optional parameter to set the DPI of the encoded image
/// (if supported by the specific MIME type).</param>
/// <returns>A newly constructed MIME / Image record with the WriteableBitmap
/// encoded into the specified MIME type.</returns>
public static async Task <NdefMimeImageRecord> CreateFromBitmap(WriteableBitmap bmp, ImageMimeType mimeType,
double dpi = 96.0)
{
var imgRecord = new NdefMimeImageRecord();
await imgRecord.SetImage(bmp, mimeType, dpi);
return(imgRecord);
}
/// <summary>
/// Construct a new MIME / Image record based on a WriteableBitmap.
/// Specify the MIME type and DPI, and the image data is encoded accordingly.
/// </summary>
/// <param name="bmp">Source bitmap to use for conversion.</param>
/// <param name="mimeType">MIME type to specify the target image encoding.</param>
/// <param name="dpi">Optional parameter to set the DPI of the encoded image
/// (if supported by the specific MIME type).</param>
/// <returns>A newly constructed MIME / Image record with the WriteableBitmap
/// encoded into the specified MIME type.</returns>
public static async Task<NdefMimeImageRecord> CreateFromBitmap(WriteableBitmap bmp, ImageMimeType mimeType,
double dpi = 96.0)
{
var imgRecord = new NdefMimeImageRecord();
await imgRecord.SetImage(bmp, mimeType, dpi);
return imgRecord;
}
/// <summary>
/// Utility method to convert the MIME type enumeration used by this class to the
/// platform's Bitmap Encoder GUID.
/// </summary>
/// <param name="mimeType">MIME type to convert.</param>
/// <returns>GUID that can be used in the bitmap encoder to encode this MIME type.</returns>
public static Guid GetBitmapEncoderIdForMimeType(ImageMimeType mimeType)
{
switch (mimeType)
{
case ImageMimeType.Png:
return BitmapEncoder.PngEncoderId;
case ImageMimeType.Jpg:
case ImageMimeType.Jpeg:
return BitmapEncoder.JpegEncoderId;
case ImageMimeType.JpegXr:
return BitmapEncoder.JpegXREncoderId;
case ImageMimeType.Bmp:
return BitmapEncoder.BmpEncoderId;
case ImageMimeType.Gif:
return BitmapEncoder.GifEncoderId;
case ImageMimeType.Tiff:
return BitmapEncoder.TiffEncoderId;
default:
throw new ArgumentOutOfRangeException();
}
}
/// <summary>
/// Set an image to this class by specifying the WritableBitmap and the target encoding and
/// optionally the DPI to set for the target file (if supported by the target file type).
/// </summary>
/// <remarks>
/// The method takes the bitmap as input and uses the BitmapEncoder to encode
/// the image data into the specified MIME type and file format. The encoded contents are
/// then stored to the payload of the record, the MIME type is set as the type of the record.
/// </remarks>
/// <param name="bmp">Input bitmap to encode and set as payload of this record.</param>
/// <param name="mimeType">MIME type to use for encoding this image.</param>
/// <param name="dpi">Target DPI if supported by the target file / MIME format.</param>
/// <returns>Task to await completion of the asynchronous image encoding.</returns>
public async Task SetImage(WriteableBitmap bmp, ImageMimeType mimeType, double dpi = 96.0)
{
var encoderId = GetBitmapEncoderIdForMimeType(mimeType);
byte[] pixels;
using (var stream = bmp.PixelBuffer.AsStream())
{
pixels = new byte[(uint)stream.Length];
await stream.ReadAsync(pixels, 0, pixels.Length);
}
using (var imgStream = new MemoryStream())
{
var raImgStream = imgStream.AsRandomAccessStream();
var encoder = await BitmapEncoder.CreateAsync(encoderId, raImgStream);
encoder.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Premultiplied,
(uint)bmp.PixelWidth,
(uint)bmp.PixelHeight,
dpi,
dpi,
pixels);
await encoder.FlushAsync();
await raImgStream.FlushAsync();
Payload = imgStream.ToArray();
Type = ImageMimeTypes[mimeType];
}
}
