private void BtnGetSheets_Click(object sender, EventArgs e) { if (ValidationLogic.InvalidFile(TbxFilePath)) { ErrorActions.InvalidFile(); } else { try { /* using form inputs open the file and loop through all sheets within * the workbook, adding the name of each sheet encountered into a list * box that the user can select from. */ string file = TbxFilePath.Text.ToString(); ExcelThread.OpenWorkbook(file); ExcelThread.GetSheets(); LbxSheetNames.Items.Clear(); for (int i = 1; i <= ExcelThread.Worksheets.Count; i++) { Microsoft.Office.Interop.Excel.Worksheet sheet = ExcelThread.Worksheets[i]; LbxSheetNames.Items.Add(sheet.Name.ToString()); } // make the next stage of the process/application visible. GrpSheetAndHeader.Visible = true; } catch { ErrorActions.FailOpenFile(); } } }