Question

I use C# & Excel Intropt.dll for my project

I want Open my xlsx file and adding a value (For Example “1”) to All Of my cells in Sheet1.

How can i achieve this?

Like this:

12   14    19    22

81   91    26    62

Result:

13   15    20    23

82   92    27    63

Answer 1

You can use this snippet. Cells[1,1] is the first cell at the top left corner. This gets the first sheet, but you can also reference them by name.

Excel.Application xlApp;
Excel.Workbook xlWorkBook;
Excel.Worksheet xlWorkSheet;
object misValue = System.Reflection.Missing.Value;

xlApp = new Excel.ApplicationClass();
xlWorkBook = xlApp.Workbooks.Open(_filename, 0, true, 5, "", "", true, Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, 1, 0);
xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);

//You can loop through all cells and use i and j to get the cells
xlWorkSheet.Cells[1,1].Value2 = Convert.ToInt32(xlWorkSheet.Cells[1,1].Value2) + 1;

xlWorkBook.Close(false, misValue, misValue);
xlApp.Quit();