当前位置:编程学习 > C#/ASP.NET >>

C#读取串口数据不完整是怎么回事?

发过去了 读的时候只读了一些,还有些没有读出来!
用的是SerialPort控件,没有用DataReceived事件
另外开的线程读的,请问怎么解决呢??? --------------------编程问答-------------------- 用VC不行吗? --------------------编程问答-------------------- 不会,先帮下解决下问题先!                --------------------编程问答--------------------
DataReceived
--------------------编程问答-------------------- 你要用一个全局变量来保存每次读到的数据,直到读取完整了,也就是说,erialPort1.Read(data, 0, data.Length);有时候并不能一次性把数据读取完整,之前我也遇到过这样的问题,给你一段代码参考一下
#region serialPort1_DataReceived - 接受COM数据
        private void serialPort1_DataReceived(object sender, SerialDataReceivedEventArgs e)
        {
            lock (locker)
            {
                switch (e.EventType)
                {
                    case SerialData.Chars:
                        byte[] data = new byte[256];
                        int length = serialPort1.Read(data, 0, data.Length);

                        if (length > 0)
                        {
                            if (data[length - 1] == 13)
                            {
                                if (length > 1)
                                {
                                    buffer += Encoding.ASCII.GetString(data, 0, length - 1);
                                }
                                string temp = buffer;
                                buffer = "";
                                //DealBarcode(temp);
                                this.Invoke(new DealBarcodeEvent(this.DealBarcode), new object[] { temp });
                            }
                            else if (data[length - 1] == 10)
                            {
                                if (length == 1)
                                {
                                    return;
                                }
                                else if (length == 2)
                                {
                                    string temp = buffer;
                                    buffer = "";
                                    //DealBarcode(temp);
                                    this.Invoke(new DealBarcodeEvent(this.DealBarcode), new object[] { temp });
                                }
                                else // length > 2 含有数据
                                {
                                    buffer += Encoding.ASCII.GetString(data, 0, length - 2);
                                    string temp = buffer;
                                    buffer = "";
                                    //DealBarcode(temp);
                                    this.Invoke(new DealBarcodeEvent(this.DealBarcode), new object[] { temp });
                                }
                            }
                            else
                            {
                                buffer += Encoding.ASCII.GetString(data, 0, length);
                            }
                        }
                        break;
                    case SerialData.Eof:
                        break;
                }
            }           
        }
        #endregion

其中的temp就是前面说的全局变量
而this.Invoke(new DealBarcodeEvent(this.DealBarcode), new object[] { temp });就是在判定所有数据读完了之后,做的一段业务逻辑,自己去改改吧 --------------------编程问答-------------------- 比如一个扫码枪读到条码之后,你需要通过多次serialPort1.Read(data, 0, data.Length);才能读到完整的数据,要不然就会出现断码的现象,特别是那种USB转COM的设备,这种情况特别容易出现 --------------------编程问答-------------------- 多次serialPort1.Read(data, 0, data.Length);什么意思,怎么做!!!上面给的代码看不懂! --------------------编程问答-------------------- 1、设置大一点的缓冲区,如果一次读取不完,自然要分多次读取!
2、关于SerialPort写串口程序的问题
--------------------编程问答-------------------- 上面的代码用的是事件,你先试试看
补充:.NET技术 ,  C#
CopyRight © 2012 站长网 编程知识问答 www.zzzyk.com All Rights Reserved
部份技术文章来自网络,