无法在 Azure 函数中使用 JpegBitmapEncoder

Question

在测试 Azure Functions 时，我编写了以下 blob 触发代码：

#r "System.Drawing"
#r "PresentationCore"
#r "WindowsBase"

using System.Drawing.Imaging;
using System.Windows;
using System.Windows.Media;
using System.Windows.Media.Imaging;

public static void Run(Stream imageStream, string providerName, string imageKey, string extension, Stream outputStream, TraceWriter log)
{
    log.Info($"Function triggered by blob\n Name:{imageKey} \n Size: {imageStream.Length} Bytes");

    var decoder = BitmapDecoder.Create(imageStream, BitmapCreateOptions.PreservePixelFormat | BitmapCreateOptions.IgnoreColorProfile, BitmapCacheOption.None);
    BitmapFrame image = decoder.Frames[0];

    double ratio = Math.Min(200 / (double)image.PixelWidth, 200 / (double)image.PixelHeight);
    var target = new TransformedBitmap(image, new ScaleTransform(ratio, ratio, 0, 0));
    image = BitmapFrame.Create(target);

    var encoder = new JpegBitmapEncoder() { QualityLevel = 85 };
    encoder.Frames.Add(image);
    //encoder.Save(outputStream);
}

如果我取消注释最后一行，我会收到以下错误：

Exception while executing function: Functions.ProcessImageTest. mscorlib: Exception has been thrown by the target of an invocation. PresentationCore: Specified method is not supported.

我不明白如果不能使用 Save 方法，为什么 JpegBitmapEncoder 可用...

我错过了什么？

Answer 1

这可能是由于有关访问 win32k.sys \ GDI+ API 的沙盒限制。您可以在此处查看有关沙箱的更多详细信息 https://github.com/projectkudu/kudu/wiki/Azure-Web-App-sandbox#win32ksys-user32gdi32-restrictions

我也可以验证这一点，但我需要应用名称（您可以直接共享它或 indirectly，但通常图形 API 无法在应用服务上可靠地工作。

Answer 2

我最终找到了以下解决方案：

run.csx

#r "System.Drawing"
#r "PresentationCore"
#r "WindowsBase"
#r "Microsoft.WindowsAzure.Storage"

using Microsoft.WindowsAzure.Storage.Blob;
using System.Drawing.Imaging;
using System.Windows;
using System.Windows.Media;
using System.Windows.Media.Imaging;

public static void Run(Stream imageStream, string imageName, string extension, CloudBlockBlob outputBlob, TraceWriter log)
{
    log.Info($"Function triggered by blob\n Name:{imageName} \n Size: {imageStream.Length} Bytes");

    var decoder = BitmapDecoder.Create(imageStream, BitmapCreateOptions.PreservePixelFormat | BitmapCreateOptions.IgnoreColorProfile, BitmapCacheOption.None);
    BitmapFrame image = decoder.Frames[0];

    double ratio = Math.Min(200 / (double)image.PixelWidth, 200 / (double)image.PixelHeight);
    var target = new TransformedBitmap(image, new ScaleTransform(ratio, ratio, 0, 0));
    image = BitmapFrame.Create(target);

    var encoder = new JpegBitmapEncoder() { QualityLevel = 85 };
    encoder.Frames.Add(image);

    using (var outputStream = new MemoryStream())
    {
        encoder.Save(outputStream);
        outputStream.Position = 0;
        outputBlob.Properties.ContentType = "image/jpeg";
        outputBlob.UploadFromStream(outputStream);
    }
}

function.json

{
  "bindings": [
    {
      "name": "imageStream",
      "type": "blobTrigger",
      "direction": "in",
      "path": "input-container/{imageName}.{extension}",
      "connection": "AzureWebJobsDashboard"
    },
    {
      "type": "blob",
      "name": "outputBlob",
      "path": "output-container/{imageName}.jpg",
      "connection": "AzureWebJobsDashboard",
      "direction": "inout"
    }
  ],
  "disabled": false
}

无法在 Azure 函数中使用 JpegBitmapEncoder

Cannot use JpegBitmapEncoder in Azure Function

c#

azure

azure-functions