in my c# program, i try to use wrtie something to excel. i find a method on the internet, using Microsoft.Office.Interop.Excel class. but when i use Microsoft.Office.Interop.Excel,it said that no Interop class found. i have already had Microsoft Office 12.0 Object Library reference in my project
You need to add Microsoft.Office.Interop.Excel.dll
to your project. See the example http://msdn.microsoft.com/en-us/library/dd264733.aspx