How can I deal with "no constructors defined" and "type cannot be embedded" exceptions?

Question

After adding the Excel 12 reference (which added Microsoft.Office.Interop.Excel and VBIDE DLLs), I copy-and-pasted the code from here, namely this:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using Excel = Microsoft.Office.Interop.Excel;

namespace WindowsFormsAppExcelTest
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void buttonCreateExcelFile_Click(object sender, EventArgs e)
        {
            Excel.Application xlApp;
            Excel.Workbook xlWorkBook;
            Excel.Worksheet xlWorkSheet;
            object misValue = System.Reflection.Missing.Value;
            xlApp = new Excel.ApplicationClass();
            xlWorkBook = xlApp.Workbooks.Add(misValue);
            xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);
            xlWorkSheet.Cells[1, 1] = "http://csharp.net-informations.com";
            xlWorkBook.SaveAs("csharp-Excel.xls",
            Excel.XlFileFormat.xlWorkbookNormal, misValue, misValue, misValue, misValue,
            Excel.XlSaveAsAccessMode.xlExclusive, misValue, misValue, misValue, misValue, misValue);
            xlWorkBook.Close(true, misValue, misValue);
            xlApp.Quit(); releaseObject(xlWorkSheet);
            releaseObject(xlWorkBook);
            releaseObject(xlApp);
            MessageBox.Show("Excel file created , you can find the file c:\\csharp-Excel.xls"); 
        }

        private void releaseObject(object obj)
        {
            try
            {
                System.Runtime.InteropServices.Marshal.ReleaseComObject(obj); obj = null;
            }
            catch (Exception ex)
            {
                obj = null;
                MessageBox.Show("Exception Occured while releasing object " + ex.ToString());
            }
            finally
            {
                GC.Collect();
            }
        } 

    } // class
} // namespace

However, it fails to build with two err msgs:

The type 'Microsoft.Office.Interop.Excel.ApplicationClass' has no constructors defined

-and:

Interop type 'Microsoft.Office.Interop.Excel.ApplicationClass' cannot be embedded. Use the applicable interface instead.

...both of which point to this line as the culprit:

xlApp = new Excel.ApplicationClass();

If I remove "new" from that line, the first err msg changes to:

'Microsoft.Office.Interop.Excel.ApplicationClass' is a 'type', which is not valid in the given context

So it's a "Catch 2" situatiion - whichever I do, it catches two errors.

What can I do to remedy this?

Answer 1

Changing the code to this:

private void buttonCreateExcelFile_Click(object sender, EventArgs e)
{
    Excel.Application xlApp;
    Excel.Workbook xlWorkBook;
    Excel.Worksheet xlWorkSheet;
    object misValue = System.Reflection.Missing.Value;
    xlApp = new Excel.Application();
    . . .

...works (using Excel.Application instead of Excel.ApplicationClass).