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 < 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, "table" + i);

                    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;
        }