Windows Phone运行时:RendertargetBitmap / IBuffer到Base64,反之亦然

时间:2015-06-19 10:49:36

标签: c# windows-runtime windows-phone-8.1 win2d

我目前正在尝试将我从RenderTargetBitmap转换为Base64String的IBuffer转换为Base64String,反之亦然。我在Silverlight中成功地做了类似的事情,但现在在Windows运行时,有很多库缺失,我不知道现在要尝试什么。

以下是我最新的示例代码,它不会产生任何错误,但是当我尝试运行它时,它会让我的应用程序崩溃。有什么建议吗?

提前致谢

        var bitmap = new RenderTargetBitmap();
        await bitmap.RenderAsync(drawingPanel);

        IBuffer pixel = await bitmap.GetPixelsAsync();

        String b64 = CryptographicBuffer.EncodeToBase64String(pixel);

        IBuffer backpixel = CryptographicBuffer.DecodeFromBase64String(b64);

        WriteableBitmap wb = new WriteableBitmap(bitmap.PixelWidth, bitmap.PixelHeight);
        wb.SetSource(backpixel.AsStream().AsRandomAccessStream());

        imageBox.Source = wb;

imageBox是一个XAML元素,用于检查转换是否成功

编辑:我对此代码没有例外,应用程序只是冻结

2 个答案:

答案 0 :(得分:2)

RenderTargetBitmap renderTargetBitmap = new RenderTargetBitmap();
            await renderTargetBitmap.RenderAsync(MyCanvas);
            var bitmap = renderTargetBitmap;
            var img = (await bitmap.GetPixelsAsync()).ToArray();
            var encoded = new InMemoryRandomAccessStream();
            var encoder = await BitmapEncoder.CreateAsync(
                BitmapEncoder.PngEncoderId, encoded);
            encoder.SetPixelData(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Straight,
                (uint)bitmap.PixelWidth, (uint)bitmap.PixelHeight, 96, 96, img);
            await encoder.FlushAsync();
            encoded.Seek(0);
            var bytes = new byte[encoded.Size];
            await encoded.AsStream().ReadAsync(bytes, 0, bytes.Length);
            return Convert.ToBase64String(bytes);

有时这对我有用,遗憾的是它有时会出错但我不知道为什么

答案 1 :(得分:0)

使用以下内容,我想我会工作

                    var bitmap = new RenderTargetBitmap();
                    await bitmap.RenderAsync(drawingPanel);

                    IBuffer pixel = await bitmap.GetPixelsAsync();
                    Stream stream = pixel.AsStream();
                    BitmapImage bitmapImage = new BitmapImage();
                    using (IRandomAccessStream raStream = stream.AsRandomAccessStream())
                    {
                        bitmapImage.SetSource(raStream);
                    }
                    imageBox.Source = bitmapImage;