Скачать или смотреть How to Save to an Existing Excel File without Opening a New One in C#

Discover how to efficiently save data from a DataGridView to an existing Excel file in C# using ClosedXML, allowing you to append new rows without overwriting old data.
---
This video is based on the question https://stackoverflow.com/q/62537019/ asked by the user 'Recep Enes Çevlik' ( https://stackoverflow.com/u/13798699/ ) and on the answer https://stackoverflow.com/a/62537590/ provided by the user 'Mikael' ( https://stackoverflow.com/u/12059568/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: save to existing excel file without opening new excel file

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Save to an Existing Excel File without Opening a New One in C#

Working with Excel files in C# can be a bit challenging, especially when you want to save new data to an existing file without overwriting the previous content. In this guide, we will address the problem of appending new rows from a DataGridView to an existing Excel file. You'll learn to use the ClosedXML Library, which simplifies the process of reading from and writing to Excel files in .xlsx format.

The Problem: Appending Data to Excel

Suppose you have a DataGridView in your C# application that displays data. When you want to save the contents to an existing Excel file, you face the issue of how to add the new data below the existing rows without creating a new Excel instance. The traditional way often leads to overwriting old data or saving the content in a completely new file.

The Solution: Using ClosedXML Library

ClosedXML makes it effortless to manipulate Excel files. Here, we will break down the solution into manageable steps, using sample code snippets to demonstrate.

Step 1: Install ClosedXML Library

First, ensure you have the ClosedXML library installed. You can easily install it via NuGet Package Manager in your Visual Studio project:

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

Step 2: Read Existing Excel Data into a DataTable

In order to preserve the existing data in the Excel file, you’ll need to read it into a DataTable. Here's how to do it:

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

Step 3: Converting DataGridView to DataTable

Next, you’ll want to convert the contents of your DataGridView to a DataTable:

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

Step 4: Saving the Merged Data Back to the Excel File

Lastly, after merging the new data with the existing one, you will save it back to the original Excel file:

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

Step 5: Triggering the Save Action

You can finally connect everything in your button click event to save data to the Excel file:

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

Conclusion

By following the steps outlined in this guide, you can seamlessly append new data from a DataGridView to an existing Excel file without overwriting previous content. The ClosedXML Library not only simplifies the process but also ensures your data remains intact.

Try implementing this solution in your projects and experience the ease of handling Excel files with C# !