在ProgressBar控件中显示进度百分比

        private void StartOrStop_Click(object sender, EventArgs e)
        {
            if (timer1.Enabled == false)
            {
                timer1.Enabled = true;
                StartOrStop.Text = "停止";
            }
            else 
            {
                timer1.Enabled = false;
                StartOrStop.Text = "开始";
            }
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            if (progressBar1.Value == progressBar1.Maximum)
            {
                progressBar1.Value = progressBar1.Minimum;
            }
            else 
            {
                progressBar1.PerformStep();
            }
            int process = 100 *
                (progressBar1.Value - progressBar1.Minimum)
                / (progressBar1.Maximum - progressBar1.Minimum);
            label1.Text = process.ToString()+"%" ;
        }