C# 学习之一：入门

【本文发布地址https://blog.youkuaiyun.com/Stack_/article/details/125560095，未经许可不得转载，转载须注明出处】

等待窗体创建完成

加入等待窗口句柄创建完成的代码，可以有效防止程序打开时卡住。

public MON()
{
	InitializeComponent();

	this.Load += new System.EventHandler(this.MainWindow_Load);
}

private void MainWindow_Load(object sender, EventArgs s)
{
	while (!this.IsHandleCreated) ;//等待窗口句柄创建完成
}

ComboBox添加列表并设定默认值

ComboBox_SelectBaudRate.Items.Clear();
ComboBox_SelectBaudRate.Items.Add("1152000");
ComboBox_SelectBaudRate.Items.Add("115200");
ComboBox_SelectBaudRate.Items.Add("57600");
ComboBox_SelectBaudRate.Items.Add("38400");
ComboBox_SelectBaudRate.Items.Add("19200");
ComboBox_SelectBaudRate.Items.Add("9600");
ComboBox_SelectBaudRate.Items.Add("4800");
ComboBox_SelectBaudRate.Items.Add("2400");
ComboBox_SelectBaudRate.Items.Add("自定义");
ComboBox_SelectBaudRate.SelectedIndex = 0;

委托

//声明委托
private delegate void Delegate_DisplayTime();
        
Delegate_DisplayTime DisplayTime = new Delegate_DisplayTime(fun_DisplayTime);

/// <summary>
/// 实例化委托,实例的参数和返回值须与声明一致
/// </summary>
private void fun_DisplayTime()
{
    string week = DateTime.Now.DayOfWeek.ToString();
    string date = DateTime.Now.DayOfYear.ToString();
    switch (week)
    {
        case "Monday": week = "星期一"; break;
        case "Tuesday": week = "星期二"; break;
        case "Wednesday": week = "星期三"; break;
        case "Thursday": week = "星期四"; break;
        case "Friday": week = "星期五"; break;
        case "Saturday": week = "星期六"; break;
        case "Sunday": week = "星期日"; break;
    }
    time.Text = DateTime.Now.ToString("[yyyy-MM-dd HH:mm:ss" + "  " + week + " " + "今年第" + date + "天]");
}

定时

//声明定时器
private System.Threading.Timer nowTime;
nowTime = new System.Threading.Timer(new TimerCallback(fun_timerCallBack), this, 1000, 500);
/// <summary>
/// 实例化
/// </summary>
private void fun_timerCallBack(object sender)
{

}

委托结合定时

上面的多线程定时器直接操作控件可能会报跨线程的错误，所以可以利用委托去刷新

private delegate void Delegate_DisplayTime();
private System.Threading.Timer nowTime;
nowTime = new System.Threading.Timer(new TimerCallback(fun_timerCallBack), this, 1000, 500);
/// <summary>
/// 实例化委托,实例的参数和返回值须与声明一致
/// </summary>
/// <summary>
/// 实例化
/// </summary>
private void fun_timerCallBack(object sender)
{
    Delegate_DisplayTime DisplayTime = new Delegate_DisplayTime(fun_DisplayTime);
    this.BeginInvoke(DisplayTime, new object[]{});
}
private void fun_DisplayTime()
{
    string week = DateTime.Now.DayOfWeek.ToString();
    string date = DateTime.Now.DayOfYear.ToString();
    switch (week)
    {
        case "Monday": week = "星期一"; break;
        case "Tuesday": week = "星期二"; break;
        case "Wednesday": week = "星期三"; break;
        case "Thursday": week = "星期四"; break;
        case "Friday": week = "星期五"; break;
        case "Saturday": week = "星期六"; break;
        case "Sunday": week = "星期日"; break;
    }
    time.Text = DateTime.Now.ToString("[yyyy-MM-dd HH:mm:ss" + "  " + week + " " + "今年第" + date + "天]");

自动扫描串口

/// <summary>
/// 自动扫描可用串口并添加到列表中，利用定时加委托调用
/// </summary>
private void AutoScanCom()
{
    string[] Ports = SerialPort.GetPortNames();//获取本机的所有串口名称

    if (Ports == null)//无串口
    {
        comboBox_selectCOM.Items.Clear();//清除控件中当前值
        comboBox_selectCOM.Text = "";
    }
    else
    {
        portscnt = 0;
        foreach (string P in Ports)  //string ports -> P
        {
            portscnt++;
        }
        if (portscnt != lastportscnt)//这次串口数量与上次不一致
        {
            lastportscnt = portscnt;
            comboBox_selectCOM.Text = "";
            comboBox_selectCOM.Items.Clear();//清除控件中当前值
            foreach (string p in Ports)  //循环检索Ports
            {
                bool PortExist = false;  //标记串口是否可用
                try   //检测串口是否可用
                {
                    SerialPort SP = new SerialPort(p);
                    SP.Open();
                    SP.Close();
                    PortExist = true;
                }
                catch
                {
                    PortExist = false;
                }
                if (PortExist)  //此串口可用
                {
                    //将可用串口名称添加到下拉列表控件中
                    comboBox_selectCOM.Items.Add(p);
                    comboBox_selectCOM.SelectedIndex = 0;
                }
            }
        }

    }
}

防止已打开的串口拔出导致窗体卡死

/// <summary>
/// 热插拔，防止打开了串口，拔出后卡死
/// </summary>
private void HotPlug()
{
    if (PortOpened== true)  //如果已经打开串口,此标志在点击打开串口时标记为true
    {
        if (!SP_toINFP.IsOpen)  //如果串口设备被拔出, serialport控件会关闭串口资源
        {
            int i = 0;
            string[] portsName = SerialPort.GetPortNames();  //查找当前计算机还有没有正在使用的 COM口
            for (; i < portsName.Length; i++)
            {
                if (SP.PortName == portsName[i])
                    break;
            }
            if (i == portsName.Length)//已被拔出
            {
                SP.Close();
                PortOpened= false; 
            }
        }
    }
}

串口接收

using System.IO.Ports;
SerialPort SP = new SerialPort();
SP .DataReceived += new SerialDataReceivedEventHandler(COM_Received);
private void COM_Received(object sender, SerialDataReceivedEventArgs e)
{
    this.BeginInvoke((EventHandler)(delegate {
        try
        {
			int bufferLen = SP.BytesToRead;
			if (bufferLen > 0)
            {
            	byte[] spDataBuff = new byte[bufferLen];
                SP.Read(spDataBuff, 0, bufferLen);
                ......
			}
        }
        catch
        {

        }
    
    
        } )
    );
}