在Azure的功能不能使用JpegBitmapEncoder

Question

在测试Azure的功能，我写了下面的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); 
} 

如果我去掉最后一行，我得到以下错误：

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

我不明白为什么JpegBitmapEncoder可用，如果一个人不能使用Save方法...

我在想什么？

Answer 1

我终于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 
} 

Answer 2

这可能是由于有关访问win32k.sys \ GDI+ API的沙盒阻止。 你可以看看这里了解沙箱https://github.com/projectkudu/kudu/wiki/Azure-Web-App-sandbox#win32ksys-user32gdi32-restrictions

我还可以验证更多的细节，但我需要的应用程序名称（你可以分享它直接或indirectly但总体图形API将无法可靠地工作，上。应用服务