WriteableBitmapExtensions.cs

//  Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//  The MIT License (MIT)
// 
//  Permission is hereby granted, free of charge, to any person obtaining a copy
//  of this software and associated documentation files (the "Software"), to deal
//  in the Software without restriction, including without limitation the rights
//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//  copies of the Software, and to permit persons to whom the Software is
//  furnished to do so, subject to the following conditions:
// 
//  The above copyright notice and this permission notice shall be included in
//  all copies or substantial portions of the Software.
// 
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
//  THE SOFTWARE.
//  ---------------------------------------------------------------------------------

using System;
using System.Runtime.InteropServices.WindowsRuntime;
using System.Threading.Tasks;
using Windows.Graphics.Imaging;
using Windows.Storage;
using Windows.UI.Xaml.Media.Imaging;

namespace PhotoSharingApp.Universal.Extensions
{
    /// <summary>
    /// Provides extension methods for the <see cref="WriteableBitmap" /> class.
    /// </summary>
    public static class WriteableBitmapExtensions
    {
        /// <summary>
        /// Saves the given <see cref="WriteableBitmap" /> to a specified storage file.
        /// </summary>
        /// <param name="writeableBitmap">The writeable bitmap.</param>
        /// <param name="storageFile">The storage file.</param>
        public static async Task SaveToStorageFile(this WriteableBitmap writeableBitmap, IStorageFile storageFile)
        {
            using (var writestream = await storageFile.OpenAsync(FileAccessMode.ReadWrite))
            {
                var encoder = await BitmapEncoder.CreateAsync(BitmapEncoder.JpegEncoderId, writestream);

                using (var pixelStream = writeableBitmap.PixelBuffer.AsStream())
                {
                    var pixels = new byte[pixelStream.Length];
                    await pixelStream.ReadAsync(pixels, 0, pixels.Length);

                    encoder.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Ignore,
                        (uint)writeableBitmap.PixelWidth, (uint)writeableBitmap.PixelHeight, 96.0, 96.0, pixels);

                    await encoder.FlushAsync();
                }
            }
        }
    }
}