private void UserInfo_Load(object sender, EventArgs e)
        {
           
            dataGridView2.DataSource = BindGridview();
        
        }
private void dataGridView2_RowsAdded(object sender, DataGridViewRowsAddedEventArgs e)
        {
            using (WebClient wc = new WebClient())
            {
                //开始异步下载，图片URL路径请根据实际情况自己去指定
                //同时将DataGridView当前行的行号传递过去，用于指定图片显示的CELL
                wc.DownloadDataAsync(new Uri(dataGridView2.Rows[e.RowIndex].Cells["Column2"].Value.ToString()), e.RowIndex);
                //WebClient 下载完毕的响应事件绑定
                wc.DownloadDataCompleted += new DownloadDataCompletedEventHandler(wc_DownloadDataCompleted);
            }
        }
  ///<summary>
        /// 图片下载完毕，显示于对应的CELL
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        void wc_DownloadDataCompleted(object sender, DownloadDataCompletedEventArgs e)
        {
            ////如果下载过程未发生错误，并且未被中途取消
            if (e.Error == null && !e.Cancelled)
            {
                ////将图片显示于对应的指定单元格， e.UserState 就是传入的 e.RowIndex
                ////e.Result 就是下载结果
                this.dataGridView2.Rows[(int)e.UserState].Cells["V_httppath"].Value = e.Result;
            }
        }