htm5-websocket实现数据查询应用

在之前的文章讲述了使用Websocket调用远程方式的功能,在这基础我们可以简单地使用WebSocket进行数据处理方面的应用;只需要在方法执行相关的数据库操作返回即可,结合jeasyui库所提供丰富的控件进行数据应用处理变得非常简单的事情.下面使用jeasyui和WebSocket实现一个查询Northwind数据订单的应用案例.

首先分析一下以下一个订单查询案例所需要的逻辑功能.

从以上的案例图中可以得到包括的功能如下：

1)雇员查询
2)客户查询
3)订单分页查询
4)订单明细查询

C#代码

针对以上功能可以实现简单的逻辑查询，代码如下：

public class Handler
    {
        public IList<BLEmployee> ListEmployees()
        {
            Console.WriteLine("List Employees");
            IList<BLEmployee> items = new Expression().List<Employee, BLEmployee>();
            return items;
        }
 
        public IList<BLCustomer> ListCustomers()
        {
            Console.WriteLine("List Customers");
            IList<BLCustomer> items = new Expression().List<Customer, BLCustomer>();
            return items;
        }
 
 
        public IList<BLOrderDetail> GetOrderDetail(int orderid)
        {
            Console.WriteLine("GetOrderDetail   OrderID:{0}", orderid);
            return (Order.orderID == orderid).List<OrderDetail, BLOrderDetail>();
        }
 
        public OrderSearchResult ListOrder(OrdersSearch search)
        {
            Console.WriteLine("ListOrder Employee:{0}\t Customer:{1}", search.EmployeeID, search.CustomerID);
            OrderSearchResult result = new OrderSearchResult();
            Expression exp = new Expression();
            if (!string.IsNullOrEmpty(search.CustomerID))
                exp &= Customer.customerID.At() == search.CustomerID;
            if (search.EmployeeID > 0)
                exp &= Employee.employeeID.At() == search.EmployeeID;
            int count = exp.Count<Order>();
            result.Orders = exp.List<Order, BLOrder>(new Region(search.Page, search.PageSize));
            result.Count = count;
            return result;
        }
    }

借助于开源组件Smark.Data的功能，只需要编写简单的代码就能实现相应的数据查询逻辑处理．

JavaScript

定义websocket连接：

//创建连接
        function connect() {
            channel = new TcpChannel();
            channel.Connected = function (evt) {
                $('#dlgConnect').dialog('close');
                
                setTimeout(listEmployee, 50);
                setTimeout(listCustomer, 50);
                listOrder();
            };
            channel.Disposed = function (evt) {
                $('#dlgConnect').dialog('open');
            };
            channel.Error = function (evt) {
                alert(evt);
            };
            channel.Connect($('#txtHost').val());
        }

在连接创建完成事件中进行数据查询操作，由于连续进行３以上的websocket的发送操作会导致发送不成功，之于具体原因暂不清楚．所以只能通过setTimeout来控制初始化的数据查询．连接创建后就可以进行远程方法调用，进行数据查询操作具体相关代码如下:

雇员查询远程调用方法:

//雇员查询
        var callListEmployees = { url: 'Handler.ListEmployees', parameters: {} };
        function listEmployee() {
            channel.Send(callListEmployees, function (result) {
                result.data.unshift({ EmployeeID: 0, FullName: 'null' });
                $('#employees').combobox({
                    data: result.data,
                    valueField: 'EmployeeID',
                    textField: 'FullName'
                });
            });
        }

客户查询远程调用方法:

//客户查询
        var callListCustomers = { url: 'Handler.ListCustomers', parameters: {} };
        function listCustomer() {
            channel.Send(callListCustomers, function (result) {
                result.data.unshift({ CustomerID: '', CompanyName: 'null' });
                $('#customers').combobox({
                    data: result.data,
                    valueField: 'CustomerID',
                    textField: 'CompanyName'
                });
            });
        }

订单查询远程调用方法:

//订单查询
        var callListOrder = {
            url: 'Handler.ListOrder',
            parameters: { search: { EmployeeID: 0, CustomerID: null, Page: 0, PageSize: 10} }
        };
        function listOrder() {
            channel.Send(callListOrder, function (result) {
                $('#orders').datagrid('loadData', result.data.Orders);
 
                $('#pp').pagination('refresh', { total: result.data.Count });
            });
        }

订单明细远程调用方法:

//订单明细
        var callGetOrderDetail = { url: 'Handler.GetOrderDetail', parameters: {orderid:0} };
        function getOrderDetail() {
            channel.Send(callGetOrderDetail, function (result) {
             
                $('#gdOrderDetail').datagrid('loadData', result.data);
 
                 
            });
        }