c# - 在线程之间传递事件从单独的 C# 类运行

问题描述

我正在努力在与我的主表单不同的类中启动的线程之间传递数据。我相信（我可能是错的）我应该使用一个事件。我遇到的问题是，当我调用 BluetoothScan 类并在订阅事件之前启动线程时，我的订阅者始终为空：

BluetoothScan bluetoothScan = new BluetoothScan(this);            
bluetoothScan.BluetoothDeviceDiscovered += OnBluetoothDeviceDiscovered;

如何在启动线程之前订阅事件？

我有我的主要形式：

using System;

using System.Windows.Forms;

//https://docs.microsoft.com/en-us/dotnet/api/system.windows.forms.control.invoke?view=net-5.0#System_Windows_Forms_Control_Invoke_System_Delegate_System_Object___


namespace YieldMonitor
{
    public partial class MainForm : Form
    {
        public MainForm()
        {           
            InitializeComponent();
        }

        private void MainForm_Load(object sender, EventArgs e)
        {           
            
        }

        private void BtnConnectBT_Click(object sender, EventArgs e)
        {
            //Start looking for the yield monitor device.
            
            BluetoothScan bluetoothScan = new BluetoothScan(this);            
            bluetoothScan.BluetoothDeviceDiscovered += OnBluetoothDeviceDiscovered;
        }

        static void OnBluetoothDeviceDiscovered(object sender, EventArgs e)
        {
            System.Diagnostics.Debug.WriteLine("Message recieved from event");
        }

    }

}

我的班级寻找蓝牙设备，如果找到合适的设备，应该触发事件：

using InTheHand.Net.Sockets;
using System;
using System.Linq;


namespace YieldMonitor
{
    class BluetoothScan
    {

        public event EventHandler BluetoothDeviceDiscovered;

        public BluetoothScan(MainForm mainForm)
        {
            System.Diagnostics.Debug.WriteLine("Starting BluetoothScan Class");
            Run();
        }

        public void Run()
        {
            System.Diagnostics.Debug.WriteLine("Running BluetoothScan Class");

            string myDeviceName;
            ulong myDeviceAddress;

            BluetoothClient btClient = new BluetoothClient();
            BluetoothDeviceInfo[] btDevices = btClient.DiscoverDevices().ToArray();
            foreach (BluetoothDeviceInfo d in btDevices)
            {
                System.Diagnostics.Debug.WriteLine(d.DeviceName);
                System.Diagnostics.Debug.WriteLine(d.DeviceAddress);

                //have we found the device we are looking for?
                if (d.DeviceName == "DSD TECH HC-05")
                {
                    myDeviceName = d.DeviceName;
                    myDeviceAddress = d.DeviceAddress;
                    //Send out found adapter to the next stage
                    OnBluetoothScanned(EventArgs.Empty);
                    break;

                }
            }                      
        }

        protected virtual void OnBluetoothScanned(EventArgs e)
        {
            System.Diagnostics.Debug.WriteLine("Running OnBlueToothScanned");

            EventHandler handler = BluetoothDeviceDiscovered;

            if (handler != null)// we have a subscriber to our event
            {
                System.Diagnostics.Debug.WriteLine("BluetoothScanned is Not empty");
                handler(this, e);
            }
            else
            {
                System.Diagnostics.Debug.WriteLine("BluetoothScanned is Empty");
            }

        }

    }
}

编辑

我使用任务找到了一些不错的解决方案，一旦任务完成，我需要更新标签，即。

bool myDevicePaired = false;
var eventDevicePaired = new Progress<bool>(boDevicePaired => myDevicePaired = boDevicePaired);
await Task.Factory.StartNew(() => BluetoothPair.Run(myDeviceAddress, eventDevicePaired), TaskCreationOptions.LongRunning);

//Register the device is paired with the UI
if (myDevicePaired)
{
    BtnConnectBT.Text = "Disconnect?";
}

这对于我正在等待结束的任务（例如等待蓝牙设备连接）来说效果很好。

但是我开始用System.InvalidOperationException：'跨线程操作无效：控制'tbInfo'从创建它的线程以外的线程访问。尝试更新表单文本框时出错。

例子：

在我的 MainForm 类中：

我创建了一个我称之为事件接收器的东西......

private void BluetoothSocketEventReciever(object sender, EventArgs e)
{
        Debug.WriteLine("Event!!!"); //writes data to debug fine
        tbInfo.AppendText("Event!!!!"); //causing error
}

我创建了一个从设备读取的任务......

private void ReadDataFromDevice(UInt64 myDeviceAddress)
{
         BluetoothSocket bluetoothSocket = new BluetoothSocket(myDeviceAddress);
         bluetoothSocket.BluetoothDataRecieved += BluetoothSocketEventReciever;

         Task.Factory.StartNew(() => bluetoothSocket.Run(), TaskCreationOptions.LongRunning);
}

在我的 BluetoothSocket 类中，我有一个无休止的 while 循环，它将从套接字读取数据（希望如此）目前它只是创建一个空的 EventArgs 以每秒触发事件：

namespace YieldMonitor
{
    class BluetoothSocket
    {
        ulong myDeviceAddress;
        public event EventHandler BluetoothDataRecieved;

        public BluetoothSocket (ulong deviceAddress)
        {
            myDeviceAddress = deviceAddress;
        }

        public void Run()
        {
            System.Diagnostics.Debug.WriteLine("Were in BluetoothSocket ... Address: " + myDeviceAddress);
            
            while (true)
            {
                Thread.Sleep(1000);
                Debug.WriteLine("In BluetoothSocket - Address = " + myDeviceAddress);
                OnBluetoothDataRecieved(EventArgs.Empty);
            }
        }

        protected virtual void OnBluetoothDataRecieved(EventArgs e)
        {
            EventHandler handler = BluetoothDataRecieved;

            if (handler != null)
            {
                handler(this, e);
            } else
            {
                //No subscribers
            }
        }
    }
}

我确定我在这里遗漏了一些简单的东西，但是如何将数据从无限循环传递到主窗体上的文本框？

编辑

想想我刚刚整理好了。

private void BluetoothSocketEventReciever(object sender, EventArgs e)
        {
            Debug.WriteLine("Event!!!");
            tbInfo.Invoke((Action)delegate
            {
                tbInfo.AppendText("Event!!!");
            });


           //tbInfo.AppendText("Event!!!!");
        }

这是正确的方法吗？

标签： c#events

c# - 在线程之间传递事件从单独的 C# 类运行

问题描述

解决方案

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