c# Picturebox路径

 picHeadImg.ImageLocation = string.Format("http://img3.imgtn.bdimg.com/it/u=4160106393,1595591376&fm=214&gp=0.jpg");
 // picHeadImg.Image = Image.FromStream(WebRequest.Create(head_img).GetResponse().GetResponseStream());

  picHeadImg.Image = Properties.Resources.DefulatHeadImg;

picHeadImg.Load(pathname)


1.绝对路径: 
this.pictureBox.Image=Image.FromFile("C:\\test.jpg"); 
 
2.相对路径: 
Application.StartupPath;  
可以得到程序根目录  
this.pictureBox.Image=Image.FromFile(Application.StartupPath "\\test.jpg"); 
 
3.获得网络图片的路径 
 
string url="http://img.zcool.cn/community/01635d571ed29832f875a3994c7836.png@900w_1l_2o_100sh.jpg";
this.pictureBox.Image= Image.FromStream(System.Net.WebRequest.Create(url).GetResponse().GetResponseStream());


//保存

 SaveFileDialog save = new SaveFileDialog();
save.ShowDialog();
if (save.FileName != string.Empty)
 {
   picHeadImg.Image.Save(save.FileName);
 }  

 //异步加载图像,加载txtURI的图像
 pictureBox1.LoadAsync(txtURI.Text);



private void pictureBox1_LoadProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            //显示进度
            this.lblMsg.Text = string.Format("当前进度：{0}.", e.ProgressPercentage);
        }

        private void pictureBox1_LoadCompleted(object sender, AsyncCompletedEventArgs e)
        {
            //加载错误处理事件
            if (e.Error != null)
            {
                lblMsg.Text = "错误信息：" + e.Error.Message;
                return;
            }
            //如果取消
            if (e.Cancelled)
            {
                lblMsg.Text = "操作被取消。";
            }
            else
            {
                lblMsg.Text = "加载完成.";
            }
            button1.Enabled = true;
        }