读取Excel文件到DataTable--C#

兼容xls和xlsx格式，它们的连接对象不同；

xls是oledb4.0

xlsx是oledb12.0

代码如下所示：

 public static DataTable ExcelToDataTable(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}]";

            DataSet ds = new DataSet();

            //using (OleDbConnection myConn = new OleDbConnection(connStr))
            //{
            //    using (OleDbDataAdapter myCommand = new OleDbDataAdapter(sql_F, myConn))
            //    {
            //        myConn.Open();
            //        myCommand.Fill(ds);
            //    }
            //}

            //if (ds == null || ds.Tables.Count <= 0) return null;
            //return ds.Tables[0];

            
             OleDbConnection conn = null;
            OleDbDataAdapter da = null;
            DataTable dtSheetName = null;
            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 < dtSheetName.Rows.Count; i++)
                {
                    SheetName = (string)dtSheetName.Rows[i]["TABLE_NAME"];

                    if (SheetName.Contains("$") && !SheetName.Replace("'", "").EndsWith("$"))
                    {
                        continue;
                    }

                    da.SelectCommand = new OleDbCommand(String.Format(sql_F, SheetName), conn);
                    DataSet dsItem = new DataSet();
                    da.Fill(dsItem);

                    ds.Tables.Add(dsItem.Tables[0].Copy());
                }
            }
            catch (Exception ex)
            {
            }
            finally
            {
                // 关闭连接
                if (conn.State == ConnectionState.Open)
                {
                    conn.Close();
                    da.Dispose();
                    conn.Dispose();
                }
            }
            return ds.Tables[0];
        }