突破短板，传统桌面程序 使用webapi 扩展迎合web和移动端融合的需求

传统桌面程序不能完全被web和移动端替代，但是需要改造。这里要说的是巧用webapi把以前用dll和com组件,ocx等方式做接口，做分布式开发的方式，改成restful 风格api的方式实现跨平台，多客户端(类型).并分享几则案例.

1、智能储物柜

项目背景：某智慧城市项目需要用到有智能锁的储物柜，用app扫码控制存取，并和智慧城市后台交互。智能锁系统是工业的塔式控制器，使用modbus ascii协议控制，端口使用串口。储物柜配备了工控电脑32寸竖屏，工控电脑控制塔式控制器（单片机）,工控机上需要开发一套桌面程序，对外暴露储物柜的功能性（存取物品),对用户来说作为人机交互界面。话写的有点难懂还是上图吧：



规格有几种，这是不是实物忘记了。总之也没去过现场。



柜机人机界面

说明：

工作区是底部的1024*1080像素的区域，关键设计是把二维码的内容设计成了JSON，app扫描后获取到设备和意图，智慧城市后台对云主机上的中间件发起控制请求，中间件转发给柜机程序，柜机程序和塔式控制器通信，塔式控制器控制锁动作。





中间件程序界面

说明：中间使用winform+owin宿主webapi，对外暴露api，对柜机程序提供套接字连接。中间件是socket server端，柜机程序作为client。

还是晕了吧，没看懂么。简单来说柜机程序是个上位机程序，设备需要把控制锁的需求封装成api给外部调用。这里的解决方案是使用中间件，中间件对外暴露api外部发起控制请求，中间件对内（设备端程序）执行控制指令。

为了实现"网页和移动客户端控制工控设备"这个核心需求，这也是挤破了脑袋吧.呵呵呵，总算不枉费你进来围观了一回...

不留下点代码，算什么分享呢！哼！

好的，上代码：





这就是传说中的asp.net mvc webapi啊

winform宿主：

IPEndPoint ipeSender = new IPEndPoint(IPAddress.Any, 0);
EndPoint epSender = (EndPoint)ipeSender;
serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
// 首次探测时间5 秒, 间隔侦测时间2 秒
byte[] inValue = new byte[] { 1, 0, 0, 0, 0x88, 0x13, 0, 0, 0xd0, 0x07, 0, 0 };
serverSocket.IOControl(IOControlCode.KeepAliveValues, inValue, null);
IPEndPoint ipEndPoint = new IPEndPoint(IPAddress.Parse(SocketBindingIP), int.Parse(config.AppSettings.Settings["Middleware_PORT"].Value));
try
{
serverSocket.Bind(ipEndPoint);
serverSocket.Listen(1024);
backgroundWorker.WorkerSupportsCancellation = true;
backgroundWorker.RunWorkerAsync();
LogMessage(DateTime.Now + "->Socket启动成功，监听IP：" + ipEndPoint.Address.ToString() + ":" + config.AppSettings.Settings["Middleware_PORT"].Value);
}
catch (Exception ex)
{
Com.DataCool.DotNetExpand.LogHelper.Error("服务启动失败,原因:" + ex.Message);
}
btnServiceControl.Tag = 1;
btnServiceControl.Text = "停止监听";
btnServiceControl.BackColor = Color.Green;
pbxServiceStatus.BackgroundImage = Properties.Resources.online_status;
lbWebApiBaseAddress.Text = SocketBindingIP;
hostObject = WebApp.Start<RegisterRoutesStartup>("http://" + SocketBindingIP + ":5990");

public class RegisterRoutesStartup
{
public void Configuration(IAppBuilder appBuilder)
{
HttpConfiguration config = new HttpConfiguration();
//自定义路由
config.Routes.MapHttpRoute(
name: "CustomApi",
routeTemplate: "api/{controller}/{action}/{id}",
defaults: new { id = RouteParameter.Optional }
);
//只响应Json请求
var jsonFormatter = new JsonMediaTypeFormatter();
config.Services.Replace(typeof(IContentNegotiator), new JsonContentNegotiator(jsonFormatter));
appBuilder.UseWebApi(config);
}
}

就是最后一句了。owin怎么宿主webapi去看看张善友等的文章吧。

public ApiActionResult BufferBox_API_Request(string StationNo, string CellNo, string Action)
{
var result = new ApiActionResult()
{
Success = false,
Result = null,
Message = "操作失败。"
};
byte[] results = new byte[1024];
Socket clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
try
{
clientSocket.Connect(new IPEndPoint(IPAddress.Parse(conf.AppSettings.Settings["Middleware_IP"].Value), Convert.ToInt32(conf.AppSettings.Settings["Middleware_PORT"].Value)));
using (var db = new BufferBoxDBEntities())
{
var stationEntity = db.station_signin_session.Where(st => st.SessionDict == StationNo).FirstOrDefault();
if (stationEntity == null)
{
result.Message = "设备不存在或者设备编号有误！";
result.Result = "";
return result;
}
var requestEntity = new API_Request_session
{
API_Request_IP = Request.GetClientIpAddress(),
RequestID = Guid.NewGuid(),
RequestData = CellNo + "|" + Action,
RequestDataTime = DateTime.Now,
ResultData = "",
ExecuteFlag = false,
StationNo = StationNo
};
db.API_Request_session.AddObject(requestEntity);
db.SaveChanges();
clientSocket.Send(Encoding.UTF8.GetBytes("api_request:" + JsonConvert.SerializeObject(requestEntity)));
result.Success = true;
result.Message = "设备已经受理请求。";
result.Result = requestEntity.RequestID.ToString();
}
}
catch (Exception ex)
{
result.Message = "中间件发生异常：" + ex.Message;
}
return result;
}

　　这可是项目分析的关键之处啊。中间件是如何转发api请求并通知柜机客户端执行指令的呢。就是webapi里使用socket作为client去连接中间件的socket server的。

问题就是出在这里！webapi不能阻塞socket 直到柜机客户端响应之后回复了再返回给外部。

2、php页面js开POS触摸屏电脑外接的钱箱

　　这是昨天晚上接的一个小活。新年第一单，正是有了前面项目的经验，给提供了这个解决方案。

项目背景： php做的bs项目打包成桌面项目用内嵌浏览器访问php页面来代替POS触摸屏桌面程序。打印使用插件听说解决了，但是打开钱箱遇到麻烦了。由于发包方不知道网页如何控制本地设备，也不想用activex方式，所以提供了这个解决方案：

POS触摸屏上运行一windows服务程序对外提供api(控制钱箱)和php服务器端的中间件通信，中间件对外部暴露api。

这个项目图片不高大上，所以只有代码了：

using System;
using System.Net;
using System.Web.Http;
using System.Net.Sockets;
using System.Configuration;
using System.Text;

namespace MiddlewareServer
{
/// <summary>
/// POS触摸屏收银机钱箱控制API控制器
/// </summary>
public class MoneyBoxApiController : ApiController
{
public static readonly Configuration conf = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);

[HttpGet]
/// <summary>
/// 打开POS钱箱,IP取发起请求的客户端的IP，中间件以此IP为依据通知该POS机执行开钱箱动作
/// 局域网环境IP最好是静态IP，不要使用DHIP，动态获取
/// </summary>
/// <returns>{Success,Result=请求发起机器的IP地址,Message}</returns>

public ApiActionResult OpenMoneyBox()
{
var result = new ApiActionResult()
{
Success = false,
Result = null,
Message = "操作失败。"
};
byte[] results = new byte[1024];
Socket clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
try
{
clientSocket.Connect(new IPEndPoint(IPAddress.Parse(conf.AppSettings.Settings["Middleware_IP"].Value), Convert.ToInt32(conf.AppSettings.Settings["Middleware_PORT"].Value)));
string ip = Request.GetClientIpAddress();
clientSocket.Send(Encoding.UTF8.GetBytes("api_request:" + ip));
result.Result = ip;
result.Success = true;
result.Message = "请求成功。";
}
catch (Exception ex)
{
result.Message = "中间件发生异常：" + ex.Message;
}
return result;
}
}
}

　　

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.ServiceProcess;
using System.Text;
using System.Runtime.InteropServices;
using System.Configuration;
using Microsoft.Win32.SafeHandles;
using System.IO;
using System.Net.Sockets;
using System.Net;

namespace MoneyBoxSvr
{
public partial class MoneyBoxService : ServiceBase
{
[DllImport("kernel32.dll", CharSet = CharSet.Auto)]
private static extern IntPtr CreateFile(string lpFileName, int dwDesiredAccess, int dwShareMode, int lpSecurityAttributes, int dwCreationDisposition, int dwFlagsAndAttributes, int hTemplateFile);

private Configuration config;
/// <summary>
/// 打印机端口名称
/// </summary>
public string PrintPortName
{
get { return config.AppSettings.Settings["PortName"].Value; }
}

/// <summary>
/// 中间件的IP地址
/// </summary>
public string RemoteServerIP
{
get
{
return config.AppSettings.Settings["MiddlewareIP"].Value;
}
}

/// <summary>
/// 中间件监听的端口
/// </summary>
public int MiddlewarePort
{
get
{
return Convert.ToInt32(config.AppSettings.Settings["MiddlewarePort"].Value);
}
}

protected Socket clientSocket = null;
/// <summary>
/// 缓冲区
/// </summary>
protected byte[] buffers = new byte[1024];

protected System.Threading.Thread socketThread;

public MoneyBoxService()
{
InitializeComponent();
config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
}

protected override void OnStart(string[] args)
{
StartSocketThread();
}

protected override void OnStop()
{
base.OnStop();
}

protected override void OnShutdown()
{
base.OnShutdown();
socketThread.Abort();
socketThread = null;
}

private void StartSocketThread()
{
socketThread = new System.Threading.Thread(ThreadWork);
socketThread.Start();
}

/// <summary>
/// 异步接收到远程请求
/// </summary>
/// <param name="ar"></param>
private void OnReceive(IAsyncResult ar)
{
try
{
IPEndPoint ipeSender = new IPEndPoint(IPAddress.Any, 0);
EndPoint epSender = (EndPoint)ipeSender;
//结束挂起的,从特定终结点进行异步读取
if (clientSocket != null)
{
int len = clientSocket.EndReceiveFrom(ar, ref epSender);
string requestCommand = System.Text.Encoding.UTF8.GetString(buffers);
if (requestCommand.StartsWith("api_request"))
{
OpenMoneyBox();
}
}
}
catch
{

}
finally
{
try
{
IPEndPoint ipeSender = new IPEndPoint(IPAddress.Any, 0);
EndPoint epSender = (EndPoint)ipeSender;
buffers = new byte[1024];
clientSocket.BeginReceiveFrom(buffers, 0, buffers.Length, SocketFlags.None, ref epSender, new AsyncCallback(OnReceive), epSender);
}
catch
{
}
}
}

private void ThreadWork()
{
while (true)
{
if (clientSocket == null)
{
#region 建立socket连接
IPAddress ip = IPAddress.Parse(RemoteServerIP);
clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
try
{
// 首次探测时间5 秒, 间隔侦测时间2 秒
byte[] inValue = new byte[] { 1, 0, 0, 0, 0x88, 0x13, 0, 0, 0xd0, 0x07, 0, 0 };
clientSocket.IOControl(IOControlCode.KeepAliveValues, inValue, null);
clientSocket.Connect(new IPEndPoint(IPAddress.Parse(RemoteServerIP), MiddlewarePort)); //配置服务器IP与端口
#region 签到
string request = "pos_sign_in:";
clientSocket.Send(Encoding.UTF8.GetBytes(request));
IPEndPoint ipeSender = new IPEndPoint(IPAddress.Any, 0);
EndPoint epSender = (EndPoint)ipeSender;
buffers = new byte[1024];
clientSocket.BeginReceiveFrom(buffers, 0, buffers.Length, SocketFlags.None, ref epSender, new AsyncCallback(OnReceive), epSender);
#endregion
}
catch
{
if (clientSocket != null)
{
clientSocket.Close();
clientSocket = null;
}
}
#endregion
}
if (clientSocket != null )
{
#region 发0字节的包探测连接是否可用
bool blockingState = clientSocket.Blocking;
try
{
byte[] tmp = new byte[1];
clientSocket.Blocking = false;
clientSocket.Send(tmp, 0, 0);
}
catch
{
if (clientSocket != null)
{
clientSocket.Close();
clientSocket = null;
}
}
finally
{
if (clientSocket != null)
{
clientSocket.Blocking = blockingState;
}
}
#endregion
}
System.Threading.Thread.Sleep(5000);
}
}

/// <summary>
/// 开钱箱
/// </summary>
public void OpenMoneyBox()
{
IntPtr iHandle = CreateFile(PrintPortName, 0x40000000, 0, 0, 3, 0, 0);
if (iHandle.ToInt32() != -1)
{
SafeFileHandle handle = new SafeFileHandle(iHandle, true);
FileStream fs = new FileStream(handle, FileAccess.ReadWrite);
StreamWriter sw = new StreamWriter(fs, System.Text.Encoding.Default);
sw.Write(((char)27).ToString() + "p" + ((char)0).ToString() + ((char)60).ToString() + ((char)255).ToString());
sw.Close();
fs.Close();
}
}
}
}

　　好久没写博客了。就这样吧，目的就是分享和总结。还有不说你也知道的，这文章怎么看怎么“软”。希望大家体谅一下，技术把代码变成钱本身就是困难的事情。适度广告一下吧，项目和私活就是这样找上门的。