public IActionResult GetValidateCode()
{
byte[] data = null;
string code = CaptchaHelper.RandomCode(5);
HttpContext.Session.SetString("code", code);
//TempData["code"] = code;
//定义一个画板
MemoryStream ms = new MemoryStream();
using (Bitmap map = new Bitmap(80, 32))
{
//画笔,在指定画板画板上画图
//g.Dispose();
using (Graphics g = Graphics.FromImage(map))
{
g.Clear(Color.White);
g.DrawString(code, new Font("黑体", 18.0F), Brushes.Blue, new Point(4, 3));
//绘制干扰线
CaptchaHelper.PaintInterLine(g, 6, map.Width, map.Height);
}
map.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
}
data = ms.GetBuffer();
//存在session中
return(File(data, "image/jpeg"));
}