C#串口通信程序实例详解

创建c#串口通信程序之命名空间

system.io.ports命名空间中最重用的是serialport 类。

创建c#串口通信程序之创建serialport 对象

通过创建serialport 对象，我们可以在程序中控制串口通信的全过程。

我们将要用到的serialport 类的方法：

readline()：从输入缓冲区读一新行的值，如果没有，会返回null
writeline(string)：写入输出缓冲
open()：打开一个新的串口连接
close()：关闭

serialport sp = new serialport ();

默认情况下，databits 值是8，stopbits 是1，通信端口是com1。这些都可以在下面的属性中重新设置：

baudrate：串口的波特率
stopbits：每个字节的停止位数量
readtimeout：当读操作没有完成时的停止时间。单位，毫秒
还有不少其它公共属性，自己查阅msdn。

创建c#串口通信程序之串口的硬件知识

 在数据传输的时候，每个字节的数据通过单个的电缆线传输。包包括开始位，数据，结束为。一旦开始位传出，后面就会传数据，可能是5，6，7或8位，就看你的设定了。发送和接收必须设定同样的波特率和数据位数。

创建c#串口通信程序之无猫模式

 没有modem模式的电缆只是简单地交叉传送和接收线。同样dtr & dsr, 和 rts & cts也需要交叉。这里，我们三条线。互连2和3（一段的2pin连接3pin），连接两端的5pin。

创建c#串口通信程序示例程序

 如果想使用默认属性，按“save status”按钮，如果想改变属性按“property”。设定好之后，可以通信了。

主窗口的代码

#region using directives 

using system; 
using system.collections.generic; 
using system.componentmodel; 
using system.data; 
using system.drawing; 
using system.windows.forms; 
using system.io.ports; 

#endregion 
namespace serialexpample
{
    partial class form1 : form
    {
        //create instance of property page 
        //property page is used to set values for stop bits and 
        //baud rate 
        propertypage pp = new propertypage();
        //create an serial port object 
        serialport sp = new serialport();
        public form1()
        {
            initializecomponent();
        }

        private void propertybutton_click(object sender, eventargs e)
        {
            //show property dialog 
            pp.showdialog();
            propertybutton.hide();
        }

        private void sendbutton_click(object sender, eventargs e)
        {
            try
            {
                //write line to serial port 
                sp.writeline(textbox.text);
                //clear the text box 
                textbox.text = "";
            }
            catch (system.exception ex)
            {
                baudratellabel.text = ex.message;
            }

        }

        private void readbutton_click(object sender, eventargs e)
        {
            try
            {
                //clear the text box 
                textbox.text = "";
                //read serial port and displayed the data in text box 
                textbox.text = sp.readline();
            }
            catch (system.exception ex)
            {
                baudratellabel.text = ex.message;
            }
        }

        private void form1_load(object sender, eventargs e)
        {

        }

        private void form1_formclosing(object sender, formclosingeventargs e)
        {
            messagebox.show("do u want to close the app");
            sp.close();
        }

        private void startcommbutton_click(object sender, eventargs e)
        {
            startcommbutton.hide();
            sendbutton.show();
            readbutton.show();
            textbox.show();
        }

        //when we want to save the status(value) 
        private void savestatusbutton_click_1(object sender, eventargs e)
        {
            //display values 
            //if no property is set the default values 
            if (pp.brate == "" && pp.sbits == "")
            {
                databitlabel.text = "baudrate = " +
                 sp.baudrate.tostring();
                readtimeoutlabel.text = "stopbits = " +
                sp.stopbits.tostring();
            }
            else
            {
                databitlabel.text = "baudrate = " +
                 pp.brate;
                readtimeoutlabel.text = "stopbits = " + pp.sbits;
            }  //创建c#串口通信程序

            paritylabel.text = "databits = " +
             sp.databits.tostring();
            stopbitlabel.text = "parity = " +
             sp.parity.tostring();
            readtimeoutlabel.text = "readtimeout = " +
              sp.readtimeout.tostring();

            if (propertybutton.visible == true)
                propertybutton.hide();
            savestatusbutton.hide();
            startcommbutton.show();

            try
            {
                //open serial port 
                sp.open();
                //set read time out to 500 ms 
                sp.readtimeout = 500;
            }
            catch (system.exception ex)
            {
                baudratellabel.text = ex.message;
            }
        }
    }
}

创建c#串口通信程序之属性设置对话框代码:

#region using directives 
using system; 
using system.collections.generic; 
using system.componentmodel; 
using system.data; 
using system.drawing; 
using system.text; 
using system.windows.forms; 

#endregion 
namespace serialexpample
{
    partial class propertypage : form
    {
        //variables for storing values of baud rate and stop bits 
        private string baudr = "";
        private string stopb = "";

        //property for setting and getting baud rate and stop bits 
        public string brate
        {
            get
            {
                return baudr;
            }
            set
            {
                baudr = value;
            }
        }

        public string sbits
        {
            get
            {
                return stopb;
            }
            set
            {
                stopb = value;
            }
        }

        public propertypage()
        {
            initializecomponent();
        }

        private void cancelbutton_click(object sender, eventargs e)
        {
            this.brate = "";
            this.sbits = "";
            //close form 
            this.close();
        }

        private void okbutton_click_1(object sender, eventargs e)
        {
            //here we set the value for stop bits and baud rate. 
            this.brate = baudratecombobox.text;
            this.sbits = stopbitcombobox.text;
            // 
            this.close();
        }
    }
}

c#串口通信程序创建的相关内容就向你介绍到这里，希望对你了解创建c#串口通信程序的步骤和需要注意的事宜。