DEV Community

jelizaveta
jelizaveta

Posted on

How to Create Drop-down Lists in Excel Using C# .NET

In daily data management and analysis, Excel plays an indispensable role. To ensure data accuracy and consistency, Excel drop-down lists (data validation) become an extremely useful feature. They limit the values that users can enter into a cell, thereby reducing errors and improving data quality. However, manually creating a large number of drop-down lists is not only inefficient but also prone to mistakes.

This article will introduce how to automate the creation of various types of drop-down lists in Excel using the C# programming language and the powerful third-party library Spire.XLS for .NET. Through this method, you can easily batch-generate Excel files with predefined options, significantly enhancing work efficiency. Spire.XLS for .NET is a feature-rich and user-friendly Excel component that allows developers to quickly and efficiently handle Excel documents in .NET applications, including reading and writing data, formatting, chart generation, and data validation.

Preparation: Integrating Spire.XLS for .NET

Before writing code, you need to add the Spire.XLS for .NET library to your C# project. The easiest way is to install it through the NuGet Package Manager.

  1. In Visual Studio, right-click on your project and select "Manage NuGet Packages."
  2. In the "Browse" tab, search for "Spire.XLS."
  3. Select the latest stable version and click "Install."

After installation, include the necessary namespace in your C# code file:

using Spire.Xls;
Enter fullscreen mode Exit fullscreen mode

Core Feature: Creating List-Based Drop-down Lists

The most common type of drop-down list is a fixed-value list. For example, you might want users to select only from options like "Apple," "Banana," or "Orange." Below are the detailed steps and code example to implement this feature using Spire.XLS for .NET.

Code Example: Fixed Value Drop-down List 

using Spire.Xls;

namespaceSpireXlsDemo
{
internalclassProgram
    {
staticvoidMain(string[] args)
        {
// Create a Workbook object
            Workbook workbook = new Workbook();

// Get the first worksheet
            Worksheet worksheet = workbook.Worksheets[0];

// Create a string array
string[] values = newstring[] { "Apple", "Banana", "Orange", "Strawberry", "Grape" };

// Set data validation in cell A1 to restrict selectable values to those in the array
            worksheet.Range["A1"].DataValidation.Values = values;

// Save the Workbook object as an Excel file
            workbook.SaveToFile("DropdownListCreatedFromArray.xlsx", ExcelVersion.Version2016);

// Release resources occupied by the Workbook object
            workbook.Dispose();
        }
    }
}
Enter fullscreen mode Exit fullscreen mode

Advanced Application: Creating Drop-down Lists Based on Cell Ranges

In addition to fixed values, you can also use a range of cells in the Excel worksheet as the source data for the drop-down list. This method is particularly useful when the source data changes frequently; you simply update the source range, and the drop-down list will automatically update.

Code Example: Cell Range Drop-down List 

using Spire.Xls;

namespaceSpireXlsDemo
{
internalclassProgram
    {
staticvoidMain(string[] args)
        {
// Create a new Workbook object
            Workbook workbook = new Workbook();

// Load workbook data from a file
            workbook.LoadFromFile("Sample1.xlsx");

// Get the first worksheet in the workbook
            Worksheet worksheet = workbook.Worksheets[0];

// Get the cell range A3 to A8
            CellRange dataRange = worksheet.Range["A3:A8"];

// Set B1 to use the previously obtained data range for the drop-down list
            worksheet.Range["B1"].DataValidation.DataRange = dataRange;

// Save the workbook as a new file
            workbook.SaveToFile("CreateDropdownInSameWorksheet.xlsx", ExcelVersion.Version2016);

// Release workbook resources
            workbook.Dispose();
        }
    }
}
Enter fullscreen mode Exit fullscreen mode

Enhancing Experience: Custom Input Messages and Error Alerts

To improve user experience and the accuracy of data input, you can set custom input messages and error alerts for drop-down lists. When a user selects a cell containing a drop-down list, the input message will display; when invalid data is entered, an error alert will pop up.

Configure these settings in the Validation object using the following properties:

  • ShowInputMessage (bool): Whether to display the input message.
  • InputTitle (string): The title of the input message.
  • InputMessage (string): The content of the input message.
  • ShowError (bool): Whether to display the error alert.
  • ErrorTitle (string): The title of the error alert.
  • ErrorMessage (string): The content of the error alert.
  • ErrorStyle (AlertStyleType): The style of the error alert (Stop, Warning, Information).

These settings allow you to create more user-friendly Excel templates.

Conclusion

This article detailed how to use the C# programming language and the Spire.XLS for .NET library to automate the creation of drop-down lists in Excel. We explored how to create fixed-value drop-down lists and how to use cell ranges as source data, emphasizing the importance of custom input messages and error alerts in enhancing the user experience.

With Spire.XLS for .NET, developers can efficiently tackle various challenges in Excel automation, greatly improving data management and processing efficiency. Whether generating reports, creating data entry templates, or conducting complex data analysis, Spire.XLS for .NET offers powerful and flexible solutions. We encourage you to try these code examples yourself and explore the further potential of Spire.XLS for .NET in your projects. If you encounter any issues during practice, feel free to reach out.

Top comments (0)