进度条--ProgressBar和BackgroundWorker

1) 需求：就餐打卡数据处理后，插入数据库中，用进度条显示过程

2) 思路：总进度为txt文本文件的行数（数据都是按照行写入），文本文件的大小

//BackgroundWorker对象有三个主要的事件：

//DoWork - 当BackgroundWorker对象的多线程操作被执行时触发。

//RunWokerCompleted - 当BackgroundWoker对象的多线程操作完成时触发。

//ProgressChanged - 当BackgroundWorker对象的多线程操作状态改变时触发。

//WorkerReportsProgress - 如果想让BackgroundWorker对象以异步的方式报告线程实时进度，必须将该属性的值设为true。

//WorkerSupportsCancellation 布尔类型，该值指示BackgroundWorker是否支持异步取消。

//BackgroundWorker对象的ReportProgress方法用于向主线程返回后台线程执行的实时进度。 

        //总后台线程
        private BackgroundWorker bgwInsertData = new BackgroundWorker();
        //求百分比
        long totalCount = 0;
        decimal percent = 0;
     
        //源--就餐打卡记录储存 目录
        private string sourcefileDirectory = Application.StartupPath + "\\CardData";
        private string destFileDirectory = Application.StartupPath + "\\CardDataBak";        

        public FrmReadText()
        {
            InitializeComponent();

            bgwInsertData.WorkerReportsProgress = true;
            bgwInsertData.WorkerSupportsCancellation = true;

            bgwInsertData.DoWork += new DoWorkEventHandler(bkWorker_DoWork);
            bgwInsertData.ProgressChanged += new ProgressChangedEventHandler(bkWorker_ProgressChanged);
            bgwInsertData.RunWorkerCompleted += new RunWorkerCompletedEventHandler(bkWorker_RunWorkerCompleted);
        }

        private void btnReadText_Click(object sender, EventArgs e)
        {
            //1.调用bgwInsertData的RunWorkerAsync方法，用来引发DoWork事件
            bgwInsertData.RunWorkerAsync();
        }

        void bkWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            if (e.Error != null)
            {
                MessageBox.Show(e.Error.Message, "提示", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }
            else if (e.Cancelled)
            {
                MessageBox.Show("取消操作！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                return;
            }
            else
            {
                MessageBox.Show("操作成功！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                //关闭该窗体
                this.Close();
            }
        }

        void bkWorker_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            progressBar1.Value = e.ProgressPercentage;
            lblResult.Text = "已获取数据" + e.ProgressPercentage.ToString() + "%";
        }

        void bkWorker_DoWork(object sender, DoWorkEventArgs e)
        {
            BackgroundWorker worker = sender as BackgroundWorker;
            //2.在DoWork中调用自定义函数，并将引发DoWork事件的sender传递出去
            insertData(worker);  
        }

3)  效果图：