打开文件夹加载图片

        //创建OpenFileDialog对象
        OpenFileDialog openFileDialog = new OpenFileDialog();
        
        //创建一个筛选器
        openFileDialog.Filter = "jpeg文件|*.jpg";

        //设置对话框标题
        openFileDialog.Title = "打开`图片`:";

        //启用帮助按钮
        openFileDialog.ShowHelp = true;

        //如果结果为打开，则选定文件
        if (openFileDialog.ShowDialog() == DialogResult.OK)
        {
            curFileName = openFileDialog.FileName;
            curBitmap = (Bitmap)Image.FromFile(curFileName);
            Invalidate();
        }

//在窗体的Paint 事件中输入以下代码

Graphics graphics = e.Graphics;
if (curBitmap != null)
{ 
     graphics.DrawImage(curBitmap, 160, 20, curBitmap.Width, curBitmap.Height);
}