WinCE5.0嵌入式开发(摩托罗拉MC3000数据采集器，条码扫描仪)

 public Main()
        {
            InitializeComponent();
            this.txtbarcode.Focus();
        }
        //扫描txt文本文件查询操作
        private void BarCodeScan()
        {
            string code = this.txtbarcode.Text.Trim();
            string fileName = "barcodeinfo.txt";
            StreamReader sr = new StreamReader(fileName, Encoding.Default);//以gb2312字符编码格式读取文本。
            string str;
            int count=0;
            while ((str = sr.ReadLine()) != null)//读取每一行
            {
                if (str.IndexOf(code) == 0)
                {
                    this.listBoxCode.Items.Add(str);
                    this.listBoxCode.SelectedIndex = this.listBoxCode.Items.Count - 1;
                    count = count + 1;
                }
            }
            if (count == 0)
            {
                this.listBoxCode.Items.Add(code + "    无条码信息");
                this.listBoxCode.SelectedIndex = this.listBoxCode.Items.Count - 1;
            }
            sr.Close();
            this.txtbarcode.Text = null;
        }

        //点击enter后的动作
        private void txtbarcode_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (e.KeyChar.ToString() == "/r")
            {
                BarCodeScan();
            }
        }

        //删除按钮功能
        private void BtnDelete_Click(object sender, EventArgs e)
        {
            if (this.listBoxCode.SelectedItem == null)
            {
                MessageBox.Show("请先选择需要删除的行！");
            }
            else
            {
                DialogResult MsgBoxResult;//设置对话框的返回值
                MsgBoxResult = MessageBox.Show("你确定要删除此条码？", "提示", MessageBoxButtons.YesNo, MessageBoxIcon.Exclamation, MessageBoxDefaultButton.Button2);
                if (MsgBoxResult == DialogResult.Yes)//如果对话框的返回值是YES（按"Y"按钮）
                {
                    this.listBoxCode.Items.Remove(listBoxCode.SelectedItem);
                    this.txtbarcode.Focus();

                }
                if (MsgBoxResult == DialogResult.No)//如果对话框的返回值是NO（按"N"按钮）
                {
                    this.txtbarcode.Focus();
                }          
            }
        }

        // 提取字符串中为数字的字符串
        public string getNum(String str)
        {
            string ss="";
            for (int i = 0; i             {
                if (Char.IsNumber(str, i) == true)
                {
                    ss += str.Substring(i, 1);
                }
                else
                {
                    if (str.Substring(i, 1) == ",")
                    {
                        ss += str.Substring(i, 1);
                    }
                }
                   
            }
            return ss;
        }

        private void BtnOut_Click(object sender, EventArgs e)
        {
            if (this.listBoxCode.Items.Count == 0)
            {
                MessageBox.Show("没有数据可导出！");
            }
            else
            {
                using (StreamWriter sw = new StreamWriter("barcode.txt",true))
                {
                    for (int i = 0; i                     {
                        string str = listBoxCode.Items[i].ToString();
                        sw.WriteLine(getNum(str));
                    }
                    MessageBox.Show("数据导出成功！");
                } 
            }
        }

        private void BtnReset_Click(object sender, EventArgs e)
        {
            if (this.listBoxCode.Items.Count == 0)
            {
                MessageBox.Show("条码列表无数据！");
            }
            else
            {
                DialogResult MsgBoxResult;//设置对话框的返回值
                MsgBoxResult = MessageBox.Show("你确定要清空条码列表？", "提示", MessageBoxButtons.YesNo, MessageBoxIcon.Exclamation, MessageBoxDefaultButton.Button2);
                if (MsgBoxResult == DialogResult.Yes)//如果对话框的返回值是YES（按"Y"按钮）
                {
                    this.listBoxCode.Items.Clear();
                    this.txtbarcode.Focus();

                }
                if (MsgBoxResult == DialogResult.No)//如果对话框的返回值是NO（按"N"按钮）
                {
                    this.txtbarcode.Focus();
                }
            }
        }