winform 加载窗体时弹出另一个窗体并显示进度条的源码

//frmA: 源窗体
//------------------------------------------
//引用
using System.Threading;

        BackgroundWorker worker;    

        public frmA()
        {
            InitializeComponent();

            worker = new BackgroundWorker();
            worker.DoWork += new DoWorkEventHandler(worker_DoWork);
            worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(worker_RunWorkerCompleted);
        }

        /// <summary>
        /// 异步 开始事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void worker_DoWork(object sender, DoWorkEventArgs e)
        {
            //需要执行的代码

              Thread.Sleep(5000);  //让进程上卡5秒钟

        }


        /// <summary>
        /// 事件: 异步执行完成后 
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            MessageBox.Show("执行完成。", "run", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }

       //点击一个按钮后开始执行
       private void btnA_Click(object sender, EventArgs e)
        {

              //按钮要执行的代码放在 worker_DoWork  事件中执行

              //异步执行开始
            worker.RunWorkerAsync();

            //显示进度窗体
            frmB frm = new frmB(this.worker);
            frm.StartPosition = FormStartPosition.CenterScreen;
            frm.ShowDialog(this);
        }

frmB: 
//里面放了一个loading.gif图片显示进度
------------------------------------------------------------
using System;
using System.ComponentModel;
using System.Windows.Forms;

namespace test
{
    public partial class frmB: Form
    {
        public frmB(BackgroundWorker worker)
        {
            InitializeComponent();
            worker.ProgressChanged +=new ProgressChangedEventHandler(worker_ProgressChanged);
            worker.RunWorkerCompleted +=new RunWorkerCompletedEventHandler(worker_RunWorkerCompleted);
        }

        void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            this.Close();
        }

        void worker_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            //lblStatus.Text = "";
        }

        //工作完成后执行的事件  
        public void OnProcessCompleted(object sender, EventArgs e)  
        {
            this.Close();  
        } 
 
    }

　　二：在弹出的窗体里显示backgroundWorker的进度

1, backgroundWorker1的WorkerReportsProgress属性设置为true
2, 写如下事件              
private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
             progressBar.Value = e.ProgressPercentage;   
     }  

progressBar是进度条是你定义的变量..可以写在后台执行里面控制
3 .在后台执行里面
 backgroundWorker1.ReportProgress(50);
其中50就是进度调的百分比.
比如一个循环循环100次
没次backgroundWorker1.ReportProgress(循环次数);
那么效果出来 。。 哈哈