c# - 如何保存 BitmapImage WinRT

Question

我有 BitmapImage:

BitmapImage image = new BitmapImage();
image.SetSource(memStream);

我想将图像保存到磁盘以备将来查看。我找不到如何执行此操作的工作示例？第二个问题。我需要获取像素的颜色(例如:Color cl=image.GetColorPixel(X,Y))，我该怎么做？谢谢!

Answer 1

这是我前段时间在网上找到的一段代码。我不确定，但如果我没记错的话，它来自 sdk 示例或 winrt 博客

这一切都归结为 WritabelBitmap 图像(就像其他已经发布的一样)，创建一个解码器并将其推送到流中。

  /// <summary>
        /// 
        /// </summary>
        /// <param name="writeableBitmap"></param>
        /// <param name="outputFile"></param>
        /// <param name="encoderId"></param>
        /// <returns></returns>
        public static async Task SaveToFile(
            this WriteableBitmap writeableBitmap,
            IStorageFile outputFile,
            Guid encoderId)
        {
            try
            {
                Stream stream = writeableBitmap.PixelBuffer.AsStream();
                byte[] pixels = new byte[(uint)stream.Length];
                await stream.ReadAsync(pixels, 0, pixels.Length);

                using (var writeStream = await outputFile.OpenAsync(FileAccessMode.ReadWrite))
                {
                    var encoder = await BitmapEncoder.CreateAsync(encoderId, writeStream);
                    encoder.SetPixelData(
                        BitmapPixelFormat.Bgra8,
                        BitmapAlphaMode.Premultiplied,
                        (uint)writeableBitmap.PixelWidth,
                        (uint)writeableBitmap.PixelHeight,
                        96,
                        96,
                        pixels);
                    await encoder.FlushAsync();

                    using (var outputStream = writeStream.GetOutputStreamAt(0))
                    {
                        await outputStream.FlushAsync();
                    }
                }
            }
            catch (Exception ex)
            {
                string s = ex.ToString();
            }
        }