BackgroundWorker实现的winfrom中实现异步等待加载图片显示

BackgroundWorker简介

   BackgroundWorker在winfrom中有对应控件，该有三个事件：DoWork 、ProgressChanged 和 RunWorkerCompleted。

在程序中调用RunWorkerAsync方法则会启动DoWork事件的事件处理，当在事件处理过程中，调用 ReportProgress方法则会启动ProgressChanged事件的事件处理，而当DoWork事件处理完成时，则会触发RunWorkerCompleted事件。您必须非常小心，确保在 DoWork 事件处理程序中不操作任何用户界面对象（否则仍会停止响应）。而应该通过 ProgressChanged和 RunWorkerCompleted 事件与用户界面进行通信。

实现waitefrom界面的窗体，改界面自己设计。

/// <summary>
        /// 当辅助线程指示某些操作已经进行时引发
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            int progress = e.ProgressPercentage;
            this.progressBar1.Value = progress;
            //label1.Content = string.Format("{0}", progress);
        }

        /// <summary>
        /// 操作开始时在另一个线程上运行的事件处理程序
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
        {
            
        }

        /// <summary>
        /// 当辅助线程完成（无论是成功，失败或者取消）时引发
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            this.DialogResult = DialogResult.OK;
        }

调用waitefrom船体代码（DoWork事件不要重复使用）

 protected virtual void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
        {
            BackgroundWorker bw = sender as BackgroundWorker;
            for (int i = 0; i < 100; i++)
            {
                System.Threading.Thread.Sleep(1000);
                WaiteForm1 f = e.Argument as WaiteForm1;
                f.bw.ReportProgress(i);
                bw.ReportProgress(i);
            }
            object a = e.Argument;
            object b = e.Cancel;
            e.Result = "21";
        }

 private void button1_Click(object sender, EventArgs e)
        {
            WaiteForm1 wa = new WaiteForm1();

            //执行DoWork事件可传入执行的参数
            wa.bw.RunWorkerAsync(wa);

            wa.bw.DoWork += new DoWorkEventHandler(backgroundWorker1_DoWork);
            //wa.bw.RunWorkerCompleted += new RunWorkerCompletedEventHandler(backgroundWorker1_RunWorkerCompleted);
            wa.ShowDialog(this);
            this.Text = "2132";
        }