Azure功能 - 调整存储在blob容器中的图像

时间:2016-04-30 09:28:31

标签: c# azure-storage-blobs imageresizer azure-webjobssdk azure-functions

我已回答与Azure Webjob相关的this question和调整存储为blob的图片的大小,因此我尝试使用Function App

进行相同操作

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

我的功能如下:

#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();
}

关联的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
}

project.json文件:

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

现在,当我编译该函数时,我总是遇到这个错误:

  

Microsoft.Azure.WebJobs.Host:错误索引方法' Functions.ResizeBlobImage'。 Microsoft.Azure.WebJobs.Host:无法绑定Blob以键入' Microsoft.WindowsAzure.Storage.Blob.CloudBlobContainer'。

目前是否支持此类型?

1 个答案:

答案 0 :(得分:1)

支持CloudBlobContainer。我现在尝试了一个快速示例,下面的函数适用于我,使用上面显示的相同绑定元数据。我还在project.json中使用了相同版本的WebJobs SDK。

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);        
}

不确定为什么这不适合你。我不时看到一些门户网站的故障(我们正在修复的错误),这有时会导致问题。