Question

我正在写一个数据接收事件对于串行IO端口......以下是代码

 using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;
using System.IO;   //add namespaces
using System.IO.Ports;
     public class Program
        {

            //define a delegate class to handle DataReceived events
            internal delegate void SerialDataReceivedEventHanderDelegate(object sender,SerialDataReceivedEventArgs e);

            internal void DataReceived(object sender, SerialDataReceivedEventArgs e)
            {
                //place code to read and process data here
            }

            static void Main()
            {

                string myComPortName=null;
                //1. find available COM port
                string[] nameArray = null;
                nameArray = SerialPort.GetPortNames();
                if(nameArray.GetUpperBound(0)>0) {
                myComPortName = nameArray[0];  
                }
                else {
                    Console.WriteLine("Error");
                    return;
                }    

                //2. create a serialport object
                // the port object is closed automatically by use using()
                SerialPort myComPort = new SerialPort();

                myComPort.PortName = myComPortName; //the default paramit are 9600,no parity,one stop bit, and no flow control

                   private static SerialDataReceivedEventHandler SerialDataReceivedEventHandler1 =
                   new SerialDataReceivedEventHandler(ComPort.DataReceived);

                   myComPort.DataReceived+=SerialDataReceivedEventHandler1;


            }

        }

为什么在VS2010中，Line： private static SerialDataReceivedEventHandler SerialDataReceivedEventHandler1 = new SerialDataReceivedEventHandler（ComPort.DataReceived）;

告诉我： 1.无效表达术语'私人' 2.修饰符'static'对此术语无效 3.我应该在这里使用Comport吗？或者只是DataReceived ...因为它的函数名称

感谢您的回复。

Answer 1

private和static在方法范围内无效。您只能在类级别声明静态项目 - 即此处：

public class Program
{
   private static object _memberField;

   private static void MemberMethod()
   {
     // not here:
     // private static object _insideMethod; // <- will not work
   }
}

Answer 2

不需要私有静态，只需： -

var SerialDataReceivedEventHandler1 =
                   new SerialDataReceivedEventHandler(ComPort.DataReceived);

但如果您希望成为Program类的成员，请将声明移至： -

   public class Program
        {

       private static SerialDataReceivedEventHandler;

然后你需要在Main

SerialDataReceivedEventHandler1 =
                       new SerialDataReceivedEventHandler(ComPort.DataReceived);

但更有可能的是，你真的想要开始自己的类，因为“程序”并不是真正最好的地方....而处理静态类和静态方法有点凌乱

Answer 3

private用于控制类型成员的可访问性或类型本身。它不适用于作为方法一部分的变量，因为它已经是方法本身最容易访问的。

此外，静态修饰符也无效。它也适用于类型的成员，以指示该成员是否可识别实例。

你的专栏：

private static SerialDataReceivedEventHandler SerialDataReceivedEventHandler1 =  
               new SerialDataReceivedEventHandler(ComPort.DataReceived);

应该是：

SerialDataReceivedEventHandler SerialDataReceivedEventHandler1 =  
               new SerialDataReceivedEventHandler(ComPort.DataReceived);

然而，这条线似乎完全没必要。您可以将其简化为：

myComPort.DataReceived += ComPort.DataReceived;

Answer 4

该行位于main方法内。私有和静态只允许在方法之外。

Answer 5

private限定符仅适用于类定义中的成员（成员变量/方法）。 SerialDataReceivedEventHandler只是一个方法中的变量。

C＃，串行端口的事件处理程序错误

5 个答案: