Checking if an Excel Workbook is open

Question

Is there a way to see if an Excel Workbook, say DataSheet.xls, is open (in use) or not? I would like to close that Workbook if it is opened.

Answer 1

This function below will return you whether the excel file is open or not.

Second function will get you the Excel Application, Workbook & Sheet to be used for your code.

using System.Collections.Generic;
using System.IO;
using System.Linq;
using wf = System.Windows.Forms;
using xl = Microsoft.Office.Interop.Excel;

public static class ExcelTest
{   
    public xl.Application xlApp = null;
    public xl.Workbook xlWb = null;
    public xl.Worksheet xlWs = null;

    public static bool IsXlFileOpen(string xlFileName)
    {       
        try
        {       
            if (!File.Exists(xlFileName))
            {
                wf.MessageBox.Show("Excel File does not exists!");
                return false;
            }

            try
            {
                xlApp = (xl.Application)Marshal.GetActiveObject("Excel.Application");
            }
            catch (Exception ex)
            {
                return false;
            }

            foreach (xl.Workbook wb in xlApp.Workbooks)
            {
                if (wb.FullName == xlFileName)
                {
                    xlWb = wb;
                    return true;
                }
            }

            return false;
        }
        catch (Exception ex)
        {
            return false;
        }
    }

    public static void GetXlSheet(string xlFileName,
                                    string xlSheetName)
    {
        try
        {
            if (!File.Exists(xlFileName))
            {
                wf.MessageBox.Show("Excel File does not exists!");
                return false;
            }

            xlApp = (xl.Application)Marshal.GetActiveObject("Excel.Application");
            foreach (xl.Workbook wb in xlApp.Workbooks)
            {
                if (wb.FullName == xlFileName)
                {
                    if (!xlWb
                        .Sheets
                        .Cast()
                        .Select(s => s.Name)
                        .Contains(xlSheetName))
                    {
                        wf.MessageBox.Show("Sheet name does not exist in the Excel workbook!");
                        return;
                    }
                    xlWs = xlWb.Sheets[xlSheetName];
                }
            }
        }
        catch (Exception ex)
        {
            // catch errors
        }
    }   
}