Use Microsoft Graph to Retrieve Users Photos and Store Them as Azure Blobs With C#

A strange request comes your way. The photos of everyone in your organization’s Office 365 tenant need to be provided as .jpg files. They have to be imported into a proprietary app, and named based on an attribute that uniquely identifies to whom each belongs. It’s not clear yet if they just want all the photos as a giant .zip archive, or if their app runs in Azure and needs the photos stored in a storage account. You come across the Get-UserPhoto Powershell cmdlet, which seems to offer a quick solution, but it fails to deliver against those users that still have their mailbox on-premises. How to go about it?

TL;DR The sample code that retrieves photos from Office 365 and stores them both locally on disk, as well as in Azure Blob storage, can be found here.

The main goal of this post is to get users’ pictures from an Office 365 tenant. We’ll subsequently store them in 2 places: on disk and in an Azure storage account as block blobs. We’ll only target ‘live’ users, meaning those that have their account enabled and also have an employeeNumber. Our scenario further detailed:

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Using Microsoft Graph to Modify Excel Files Stored in Sharepoint Online With C#

You just want to modify the content of a few cells in an Excel file stored in Sharepoint Online, using C#. A simple goal. Maybe your experience with Sharepoint APIs is fairly limited, so you spend a while researching. There’s questions over at Stack Overflow, that mention “CSOM”, “REST APIs”, “Graph” and various other cryptic terms, but aside the various limitations with each API, a concise and clear sample proves to be elusive.

TL;DR If you’re in a hurry to get to the sample code, skip right to it.

The goal of this post is to use Microsoft Graph to read and write to an Excel file stored in Sharepoint Online. As the main focus is getting to use Graph against Sharepoint Online just to get to an Excel file, in terms of operating against the file itself we’ll be content with just reading and updating the value of a single cell.

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List vs ArrayList in Azure Functions

You’re using Azure Functions, and need to decide on the types to use in your C# code in order to implement whatever you’re trying to achieve. In today’s world of powerful cloud computing with sometimes cheap or downright free resources, is it worth pondering over the best type to use ? After all, you get 400,000 GB-s for free per month as part of the consumption plan. And the code within this Azure Function will be just a few dozen lines, tops. Would it matter selecting an efficient data structure for your implementation ?

Let’s get specific. Say storing 10 mil numbers is needed each minute as an interim step for further processing. Do you go with ArrayList or List<int> ? Your 2 options below:

Figure 1 – Function execution units for both the ArrayList and the List<int> functions against 10 mil elements, running once each minute

Oh, and you get to pay for the area under the graph of each function. How much does that come to ? Read on.

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