shgxtzcjhoudaosaomadayinwpf/RIZO_Application/Modules/RIZO_Application.Modules.ModuleName/ViewModels/ScanControlViewModel.cs

using System;
using System.Threading.Tasks;
using System.Windows.Media;
using Prism.Events;
using Prism.Regions;
using RIZO_Application.Core;
using RIZO_Application.Core.Mvvm;
using RIZO_Application.Infrastructure.Model;
using RIZO_Helper.Tools;
using System.Windows;
using System.IO.Ports;
using System.Windows.Documents;
using System.Management;

namespace RIZO_Application.Modules.ModuleName.ViewModels
{
    public class ScanControlViewModel : RegionViewModelBase, IDisposable
    {
        private readonly IEventAggregator _eventAggregator;
        private ComScanHelper _scanHelper;
        private bool _isDisposed;
        private bool _isConnected;
        private string _lastLabel;
        private DateTime _lastScanTime;
        private ManagementEventWatcher watcher= new ManagementEventWatcher(new WqlEventQuery(
            "SELECT * FROM Win32_DeviceChangeEvent WHERE EventType = 2 OR EventType = 3"));
        // 串口连接状态属性
        public bool IsConnected
        {
            get => _isConnected;
            set
            {
                if (SetProperty(ref _isConnected, value))
                {
                    // 通知依赖属性更新
                    RaisePropertyChanged(nameof(ConnectionStatusText));
                    RaisePropertyChanged(nameof(ConnectionStatusForeground));
                }
            }
        }
        // 串口连接状态文字描述
        public string ConnectionStatusText
        {
            get => IsConnected ? "扫码枪已连接" : "扫码枪未连接";
        }

        // 串口连接状态文字颜色
        public Brush ConnectionStatusForeground
        {
            get => IsConnected ? Brushes.Green : Brushes.Red;
        }
        public ScanControlViewModel(
            IRegionManager regionManager,
            IEventAggregator eventAggregator)
            : base(regionManager)
        {

            watcher.EventArrived += new EventArrivedEventHandler(DeviceChanged);
            watcher.Start();

            _eventAggregator = eventAggregator;
            IsConnected = false; // 初始状态为未连接
            InitializeScanHelperAsync().ConfigureAwait(false);
        }

        private void DeviceChanged(object sender, EventArrivedEventArgs e)
        {
            // 1. 获取设备变化前的端口列表
            string[] portsBefore = SerialPort.GetPortNames();

            // 2. 等待系统完成端口更新（重要！）
            System.Threading.Thread.Sleep(500);

            // 3. 获取设备变化后的端口列表
            string[] portsAfter = SerialPort.GetPortNames();

            // 4. 检测新增的端口
            foreach (string port in portsAfter)
            {
                if (Array.IndexOf(portsBefore, port) == -1)
                {

                }
            }

            // 5. 检测移除的端口
            foreach (string port in portsBefore)
            {
                if (Array.IndexOf(portsAfter, port) == -1)
                {

                }
            }
        }

        private async Task InitializeScanHelperAsync()
        {
            try
            {
                await StartComScan();
            }
            catch (Exception ex)
            {
                _eventAggregator.GetEvent<SystemLogEvent>().Publish($"串口初始化异常: {ex.Message}");
            }
        }

        public async Task StartComScan(string comName = "COM1",int baudRate = 9600)
        {
            if (_isDisposed)
                throw new ObjectDisposedException(nameof(ScanControlViewModel));

            
            //if (SerialConfigs.Current != null)
            //{
            //    comName = SerialConfigs.Current.ComName ?? string.Empty;
            //    baudRate = SerialConfigs.Current.BaudRate ?? 9600;
            //}

            _eventAggregator.GetEvent<SystemLogEvent>().Publish($"串口扫码枪初始化……串口：{comName} 波特率：{baudRate}");

            // 安全地释放现有实例
            await DisposeScanHelperAsync();

            _scanHelper = new ComScanHelper(comName, baudRate);
            _scanHelper.DataReceived += HandleMessage;
            _scanHelper.ErrorOccurred += HandleError;

            if (await _scanHelper.OpenAsync())
            {
                _eventAggregator.GetEvent<SystemLogEvent>().Publish($"串口扫码初始化完成");
                IsConnected = true; // 连接成功
            }
            else
            {
                MessageBox.Show($"打开串口失败");
                _eventAggregator.GetEvent<SystemLogEvent>().Publish($"串口打开失败");
                IsConnected = false; // 连接失败
            }
        }

        private void HandleError(object sender, Exception ex)
        {
            _eventAggregator.GetEvent<SystemLogEvent>().Publish($"串口通信错误: {ex.Message}");
            IsConnected = false; // 发生错误时断开连接
        }

       
        // 定义事件处理方法
        private void HandleMessage(object sender, string labelCode)
        {
            DateTime now = DateTime.Now;
            // 短时间内重复扫了同一个标签（时间间隔小于500毫秒）
            if (_lastLabel!= null && _lastLabel == labelCode && (now - _lastScanTime).TotalMilliseconds < 500)
            {
                _eventAggregator.GetEvent<SystemLogEvent>().Publish($"重复扫码过滤: {labelCode}");
                return;
            }
            _lastLabel = labelCode;
            _lastScanTime = now;
            // 打印接收到的消息信息
            //_eventAggregator.GetEvent<SystemLogEvent>().Publish($"收到串口信息: {labelCode}");
            _eventAggregator.GetEvent<ScanEvent>().Publish(labelCode);
        }

        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        private async void Dispose(bool disposing)
        {
            if (_isDisposed)
                return;

            _isDisposed = true;

            if (disposing)
            {
                await DisposeScanHelperAsync();
            }
        }

        private async Task DisposeScanHelperAsync()
        {
            if (_scanHelper != null)
            {
                try
                {
                    _scanHelper.DataReceived -= HandleMessage;
                    _scanHelper.ErrorOccurred -= HandleError;
                    await _scanHelper.DisposeAsync();
                }
                catch (Exception ex)
                {
                    _eventAggregator.GetEvent<SystemLogEvent>().Publish($"释放串口资源异常: {ex.Message}");
                }
                finally
                {
                    _scanHelper = null;
                    IsConnected = false; // 释放资源后断开连接
                }
            }
        }

        ~ScanControlViewModel()
        {
            Dispose(false);
        }
    }
}