C# Excel操作

public static DataSet ToDataTable(string filePath)
        {
            string connStr = "";
            string fileType = System.IO.Path.GetExtension(filePath);
            if (string.IsNullOrEmpty(fileType)) return null;

            if (fileType == ".xls")
                connStr = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + filePath + ";" + ";Extended Properties=\"Excel 8.0;HDR=YES;IMEX=1\"";
            else
                connStr = "Provider=Microsoft.ACE.OLEDB.12.0;" + "Data Source=" + filePath + ";" + ";Extended Properties=\"Excel 12.0;HDR=YES;IMEX=1\"";
            string sql_F = "Select * FROM [{0}]";

            OleDbConnection conn = null;
            OleDbDataAdapter da = null;
            DataTable dtSheetName = null;

            DataSet ds = new DataSet();
            try
            {
                // 初始化连接，并打开  
                conn = new OleDbConnection(connStr);
                conn.Open();

                // 获取数据源的表定义元数据                         
                string SheetName = "";
                dtSheetName = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });

                // 初始化适配器  
                da = new OleDbDataAdapter();
                for (int i = 0; i