Azure 函数 - 调整存储在 blob 容器中的图像大小

问题描述

我已经回答了 这个问题 与 Azure Webjob 和调整存储为 blob 的图像相关，因此我尝试使用 Function App

I've answered this question related to Azure Webjob and Resizing a image stored as a blob and so I am trying to do the same using a Function App

每次上传新的 blob 时，我都会发送一条新的队列消息.我的函数由队列消息触发并绑定到上传的 blob.我还有一个绑定到另一个 CloudBlobContainer 的第二个输入绑定，以便能够将新调整大小的图像上传到另一个 blob 容器.

Each time a new blob is uploaded, I send a a new queue message. My function is triggered by the queue message and bind to the uploaded blob. I also have a second input binding that binds to another CloudBlobContainer to be able to upload new resized images to another blob container.

我的函数是这样的:

#r "System.Web"
using System.IO;
using System.Web;
using ImageResizer;
using Microsoft.Azure.WebJobs;
using Microsoft.WindowsAzure;
using Microsoft.WindowsAzure.Storage;
using Microsoft.WindowsAzure.Storage.Blob;

private static readonly int[] Sizes = { 800, 500, 250 };

public static void Run(string filename, Stream blobStream, CloudBlobContainer container, TraceWriter log)
{
    log.Verbose($"C# Queue trigger function processed: {filename}");
    // Extract the filename  and the file extension
    var name = Path.GetFileNameWithoutExtension(filename);
    var ext = Path.GetExtension(filename);

    // Get the mime type to set the content type
    var mimeType = MimeMapping.GetMimeMapping(filename);

    foreach (var width in Sizes)
    {
        // Set the position of the input stream to the beginning.
        blobStream.Seek(0, SeekOrigin.Begin);

        // Get the output stream
        var outputStream = new MemoryStream();
        ResizeImage(blobStream, outputStream, width);

        // Get the blob reference
        CloudBlockBlob blob = container.GetBlockBlobReference($"{name}-w{width}.{ext}");

        // Set the position of the output stream to the beginning.
        outputStream.Seek(0, SeekOrigin.Begin);
        blob.UploadFromStream(outputStream);

        // Update the content type =>  don't know if required
        blob.Properties.ContentType = mimeType;
        blob.SetProperties();
    }               
}

private static void ResizeImage(Stream input, Stream output, int width)
{
    var instructions = new Instructions
    {
        Width = width,
        Mode = FitMode.Carve,
        Scale = ScaleMode.Both
    };
    var imageJob = new ImageJob(input, output, instructions);

    // Do not dispose the source object
    imageJob.DisposeSourceObject = false;
    imageJob.Build();
}

相关的function.json文件:

{
"bindings": [
  {
    "queueName": "newfileuploaded",
    "connection": "crazytunastorageaccount_STORAGE",
    "name": "filename",
    "type": "queueTrigger",
    "direction": "in"
  },
  {
    "path": "input-images/{queueTrigger}",
    "connection": "crazytunastorageaccount_STORAGE",
    "name": "blobStream",
    "type": "blob",
    "direction": "in"
  },
  {
    "name": "container",
    "type": "blob",
    "path": "output-images",
    "connection": "crazytunastorageaccount_STORAGE",
    "direction": "in"
  }
],
"disabled": false
}

还有 project.json 文件:

{
"frameworks": {
  "net46":{
    "dependencies": {
      "ImageResizer": "4.0.5",
      "WindowsAzure.Storage": "4.3.0"
    }
  }
 }
}

现在当我编译函数时，我总是得到这个错误:

Now when I compiled the function, I always got this error:

Microsoft.Azure.WebJobs.Host:索引方法Functions.ResizeBlobImage"出错.Microsoft.Azure.WebJobs.Host:无法将 Blob 绑定到类型Microsoft.WindowsAzure.Storage.Blob.CloudBlobContainer".

Microsoft.Azure.WebJobs.Host: Error indexing method 'Functions.ResizeBlobImage'. Microsoft.Azure.WebJobs.Host: Can't bind Blob to type 'Microsoft.WindowsAzure.Storage.Blob.CloudBlobContainer'.

目前是否支持这种类型?

Is this type supported for the moment ?

推荐答案

支持CloudBlobContainer.我现在自己尝试了一个快速示例，下面的函数对我有用，使用与上面显示的相同的绑定元数据.我也在 project.json 中使用相同版本的 WebJobs SDK.

Yes CloudBlobContainer is supported. I tried a quick sample myself now, and the below function works for me, using the same binding metadata you showed above. I'm also using the same version of the WebJobs SDK in project.json.

using System;
using Microsoft.WindowsAzure.Storage.Blob;

public static void Run(
    string blobTrigger, Stream inputBlob, Stream outputBlob,
    CloudBlobContainer container, TraceWriter log)
{
    log.Info($"Container name: {container.Name}");

    log.Info($"C# Blob trigger function processed {blobTrigger}");
    inputBlob.CopyTo(outputBlob);        
}

不知道为什么这对您不起作用.我不时看到一些 Portal 故障(我们正在修复的错误)，这些故障有时会导致问题.

Not sure why this wasn't working for you. I have seen some Portal glitches from time to time (bugs we're fixing) that sometimes cause issues.

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