Скачать или смотреть How to Create a Custom Mapping from a CSV Column to Custom Code Using CsvHelper

Discover how to make a custom mapping from a CSV column to your custom code in C# . This guide provides detailed steps and examples using CsvHelper.
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This video is based on the question https://stackoverflow.com/q/77216132/ asked by the user 'Sybaris' ( https://stackoverflow.com/u/5766311/ ) and on the answer https://stackoverflow.com/a/77217316/ provided by the user 'David Specht' ( https://stackoverflow.com/u/2355006/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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How to Create a Custom Mapping from a CSV Column to Custom Code Using CsvHelper

Working with CSV files and custom classes in C# can often present unique challenges, especially when you need to map data from CSV columns to class properties. In this post, we’ll tackle a common scenario—creating a custom mapping using the CsvHelper library to populate a list of entities while managing readonly properties.

The Problem Statement

You have a generated class, let’s call it MyClass, which inherits from Microsoft.Xrm.Sdk.Entity. This class contains properties such as Id, CreatedOn, and a dictionary for attributes. The CreatedOn property is readonly, and you need a way to set its value in the dictionary called Attributes. Specifically, your aim is to set the value for the overriddencreatedon entry in Attributes using data from a CSV file. Here’s a concise recap of the requirements:

You need to read a CSV file that includes a column for CreatedOn.

The CreatedOn property is readonly in your entity class.

The value should be set in the Attributes dictionary instead.

Now let’s dive into the solution.

Setting Up the Solution with CsvHelper

CsvHelper is a powerful library for reading and writing CSV files in C# . We'll use it to create a mapping that allows us to specify where and how our data from the CSV file will be assigned.

Step-by-step Guide to Custom Mapping

Define Your Class: Make sure your class, MyClass, is properly structured to include the required properties. Here’s a simplified version:

[[See Video to Reveal this Text or Code Snippet]]

Create the Mapping: You will create a class map that specifies how properties in your CSV should be matched to properties in your class.

[[See Video to Reveal this Text or Code Snippet]]

Adjustments for Inheritance from Entity

If your MyClass inherits from Microsoft.Xrm.Sdk.Entity, you need to use an AttributeCollection instead of a dictionary. Here’s how you would adjust the mapping accordingly:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

Setting up a custom mapping in CsvHelper allows you to efficiently manage data from CSV files and populate your classes even when dealing with readonly properties. By following the steps outlined above, you can leverage CsvHelper’s powerful features to seamlessly read and map your data, ensuring your application’s logic runs smoothly.

Feel free to experiment with the example provided, and customize it further to meet your application's requirements. Happy coding!