C # operation instance code for Excel DataTable conversion

Load Excel Public DataSet loaddatafromexcel (string filePath) {try {                 String strconn; strconn = "Provider=Microsoft.Jet.OLEDB.4.0;Data source=" + FilePath + "; Extended properties= ' Excel 8.0;                 Hdr=false;imex=1 ' "; strconn = string. Format ("Provider=microsoft.ace.oledb.12.0;data source={0}; Extended properties= ' Excel 8.0;                 hdr=yes;imex=1; ' ", FilePath);                 OleDbConnection oleconn = new OleDbConnection (strconn);                 Oleconn.open (); String sql = "SELECT * FROM [sheet1$]";//change sheet name, such as Sheet2, etc. oledbdataadapter oledaexcel = new OLE DB                 DataAdapter (SQL, oleconn);                 DataSet oledsexcle = new DataSet ();                 Oledaexcel.fill (oledsexcle, "Sheet1");                 Oleconn.close ();             return oledsexcle;             } catch (Exception err) {return null;      }         }   <summary>//DataTable directly export Excel, this method will open the DataTable data in Excel, and then manually to save to the exact location///</summary&gt         ; <param name= "DT" > to export Excel datatable</param>///<returns></returns> public Boo L Doexport (System.Data.DataTable dt) {Microsoft.Office.Interop.Excel.Application app = new Applicatio             NClass ();             if (app = = null) {throw new Exception ("Excel cannot Start"); } app.             Visible = true; Workbooks WBS = App.             Workbooks; Workbook wb = WBS.             ADD (Missing.Value); Worksheet ws = (Worksheet) WB.             WORKSHEETS[1]; int cnt = dt.             Rows.Count; int columncnt = dt.             Columns.count;  Get Data ******************** object[,] objdata = new object[cnt + 1, columncnt]; Create cache data//Get column header for (int i = 0; i < columncnt; i++) {objdata[0, I] = dt. Columns[i].             ColumnName; }//Get specific data for (int i = 0; i < cnt; i++) {System.Data.DataRow dr = dt.                 Rows[i];                 for (int j = 0; J < columncnt; J + +) {Objdata[i + 1, j] = Dr[j]; }}//********************* Write excel****************** Range r = Ws.get_range (app. Cells[1, 1], app.             cells[cnt + 1, columncnt]);             R.numberformat = "@";             R = R.get_resize (cnt+1, columncnt);             R.value2 = Objdata;             R.entirecolumn.autofit ();             App = null;         return true; }