Using C# to Create an Excel Document

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Introduction

Microsoft Excel is widely used in business because it offers the ability to present data to business executives in a way that makes sense to them. In this article, we are going to learn how easy it is to create an Excel document using C#.

Background

While looking to find an easy solution of how to read and write into a spreadsheet, I came across an article on the Microsoft site, How To Use ADO.NET to Retrieve and Modify Records in Excel. This is a wonderful article; however, formatting the data and the cosmetics of the document is not possible using this approach.

Using the Code

In order to use the class, you must add as a reference the Microsoft Excel XX.X Object Library in your project; this is a COM component; adding in Visual Studio is straight forward. Right click on your project on the Solution explorer and you should see the add reference option. Once selected, click the COM tab and look for the Excel library.
Once added, cut and paste the class below:

using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
namespace ExcelExample
{
    class CreateExcelDoc
    {
        private Excel.Application app = null;
        private Excel.Workbook workbook = null;
        private Excel.Worksheet worksheet = null;
        private Excel.Range workSheet_range = null;
        public CreateExcelDoc()
        {
            createDoc(); 
        }
        public void createDoc()
        {
            try
            {       
                app = new Excel.Application();
                app.Visible = true;
                workbook = app.Workbooks.Add(1);
                worksheet = (Excel.Worksheet)workbook.Sheets[1];
            }
            catch (Exception e)
            {
                Console.Write("Error");
            }
            finally
            {
            }
        }

public void createHeaders(int row, int col, string htext, string cell1,
string cell2, int mergeColumns,string b, bool font,int size,string
fcolor)
        {
            worksheet.Cells[row, col] = htext;
            workSheet_range = worksheet.get_Range(cell1, cell2);
            workSheet_range.Merge(mergeColumns);
            switch(b)
            {
                case "YELLOW":
                workSheet_range.Interior.Color = System.Drawing.Color.Yellow.ToArgb();
                break;
                case "GRAY":
                    workSheet_range.Interior.Color = System.Drawing.Color.Gray.ToArgb();
                break;
                case "GAINSBORO":
                    workSheet_range.Interior.Color = 
			System.Drawing.Color.Gainsboro.ToArgb();
                    break;
                case "Turquoise":
                    workSheet_range.Interior.Color = 
			System.Drawing.Color.Turquoise.ToArgb();
                    break;
                case "PeachPuff":
                    workSheet_range.Interior.Color = 
			System.Drawing.Color.PeachPuff.ToArgb();
                    break;
                default:
                  //  workSheet_range.Interior.Color = System.Drawing.Color..ToArgb();
                    break;
            }
         
            workSheet_range.Borders.Color = System.Drawing.Color.Black.ToArgb();
            workSheet_range.Font.Bold = font;
            workSheet_range.ColumnWidth = size;
            if (fcolor.Equals(""))
            {
                workSheet_range.Font.Color = System.Drawing.Color.White.ToArgb();
            }
            else {
                workSheet_range.Font.Color = System.Drawing.Color.Black.ToArgb();
            }
        }

        public void addData(int row, int col, string data, 
			string cell1, string cell2,string format)
        {
            worksheet.Cells[row, col] = data;
            workSheet_range = worksheet.get_Range(cell1, cell2);
            workSheet_range.Borders.Color = System.Drawing.Color.Black.ToArgb();
            workSheet_range.NumberFormat = format;
        }    
    }
}

Let's Go Over the Class

The first thing we do is declare the variables that are responsible for creating an Excel document.

• private Excel.Application app = null; creates the Excel document
• private Excel.Workbook workbook = null; create the workbook in the recently created document
• private Excel.Worksheet worksheet = null; allows us to work with current worksheet
• private Excel.Range workSheet_range = null; allows us to modify cells on the sheet

Note that the variables are not initialized; since they will be initialized in the constructor.

The Class has Two Methods

The class has only two methods: createHeaders and addData. Both of them take almost similar arguments. The createHeaders takes more arguments since headers must be noticeable as such. Let's explain what the arguments are:

• row,col -- They are used to tell Excel where in the cell we want the text
• htext -- This variable will hold the text for the header
• cell1,cell2 -- This will be used to specify what cells we will use, e.g. A1:B1
• mergeColumns -- It holds the number of cells we want to merge in a cell
• b -- It will hold the color of the background for the chosen cell
• font -- True or False for the font of the text on the selected cell
• size -- To specify the size of the cell
• fcolor-- Specify the color font

Below is the non-similar variable used in the addData method:

• format -- It is used to tell Excel what time of format we want

How to Use the Class

Below is an example of how to use the class and if everything goes well; you should see the spreadsheet.

CreateExcelDoc excell_app = new CreateExcelDoc();         
//creates the main header
excell_app.createHeaders(5, 2, "Total of Products", "B5", "D5", 2,"YELLOW",true,10,"n");
//creates subheaders
excell_app.createHeaders(6, 2, "Sold Product", "B6", "B6", 0, "GRAY", true,10,"");
excell_app.createHeaders(6, 3, "", "C6", "C6", 0, "GRAY", true,10,"");
excell_app.createHeaders(6, 4, "Initial Total", "D6", "D6", 0, "GRAY", true,10,"");
//add Data to cells
excell_app.addData(7, 2, "114287", "B7", "B7","#,##0");
excell_app.addData(7, 3, "", "C7", "C7", "");
excell_app.addData(7, 4, "129121", "D7", "D7", "#,##0");
//add percentage row
excell_app.addData(8, 2, "", "B8", "B8", "");
excell_app.addData(8, 3, "=B7/D7", "C8", "C8", "0.0%");
excell_app.addData(8, 4, "", "D8", "D8", "");
//add empty divider
excell_app.createHeaders(9, 2, "", "B9", "D9", 2, "GAINSBORO", true, 10, "");

Enjoy it!

History

• 26^th August, 2007: Initial post