视图:
<html>
<head>
<meta name="viewport"
content="width=device-width" />
<title>Index</title>
</head>
<body>
<div class="form-group form-row">
<label class="sr-only"
for="validCode">
验证码
</label>
<div class="col-12 ">
<div
class="input-group">
<div
class="input-group-append">
<div
class="input-group-text"><i class="fas fa-fw
fa-key"></i></div>
</div>
<input type="text"
name="validCode" id="validCode" value=""
class="form-control" placeholder="验证码" />
<div
class="input-group-addon p-0"><img
src="/yanzheng/CreateValidCodeImage" width="100"
height="38" id="validCodeImg" /></div>
</div>
</div>
</div>
<script
src="~/Plugins/jquery-3.2.1.min.js"></script>
<script>
$(function () {
$("#validCodeImg").click(function () {//点击按钮
$(this).prop("src",
"/yanzheng/CreateValidCodeImage?t=" + new
Date().getTime());//Date().getTime()拼接时间让点击图片不重复
});
})
</script>
</body>
</html>
控制器:
public ActionResult Index()
{
return View();
}
public ActionResult CreateValidCodeImage()
{
//1.生成长度为5的随机的验证码字符串
string strRandom =ValidCodeUtils.GetRandomCode(5);
//2、根据生成的验证码字符串生成验证码图片
byte[] byteImg =ValidCodeUtils.CreateImage(strRandom);
//3、将验证码字符串存入session中 key值为
Session["validCode"] =strRandom;
//4、把图片返回到视图
return File(byteImg,@"image/jpeg");
}
公共静态类:
namespace
CQUPBootstrap4.Common
{
/// <summary>
/// 公共静态
/// </summary>
public static class ValidCodeUtils //公共静态
{
/// <summary>
/// 获得随机字符串
/// </summary>
/// <param
name="intLength">随机数的长度</param>
/// <returns>随机数字符串</returns>
public static string GetRandomCode(int
intLength)
{
/*产生数字和密码混合的随机数*/
string strReturn = string.Empty;
Random random = new Random();//随机数
for (int i = 0; i < intLength;
i++)
{
char cRerult;
int intRandom = random.Next();//产生一个非负随机整数
/*根据当前随机数来确定字符串*/
//intRandom % 3 获取的是intRandom/3 得到的余数
if (intRandom % 3 == 0)
{
//产生数字
//位数来产生数字
cRerult = (char)(0x30 +
(intRandom % 10));
}
else if (intRandom % 3 == 1)
{
//位数产生大写字母:大写字符 65-97 A 65
//68 D 25 Z
cRerult = (char)(0x41 + (intRandom
% 0x1a));
}
else
{
//余数为2
//产生小写字母 98 -116
cRerult = (char)(0x61 +
(intRandom % 0x1a));
}
strReturn +=
cRerult.ToString();
}
return strReturn;
}
/// <summary>
/// 根据字符串创建验证码图片
/// </summary>
/// <param
name="strRandom">字符串</param>
/// <returns>图片的二进制数组</returns>
public static byte[] CreateImage(string
strRandom)
{
//新增图片
Bitmap newBitmap = new
Bitmap(strRandom.Length * 20, 38);
Graphics g =
Graphics.FromImage(newBitmap);
g.Clear(Color.White);
//在图片上绘制文字
SolidBrush solidBrush = new
SolidBrush(Color.Red);
g.DrawString(strRandom, new
Font("Aril", 18), solidBrush, 12, 4);
//在图片上绘制干扰线
Random random = new Random();
for (int i = 0; i < 10; i++)
{
//产生一条线,并绘制到画布。 起始点(x,y) 总结点
int x1 =
random.Next(newBitmap.Width);
int y1 =
random.Next(newBitmap.Height);
int x2 =
random.Next(newBitmap.Width);
int y2 =
random.Next(newBitmap.Height);
g.DrawLine(new
Pen(Color.DarkGray), x1, y1, x2, y2);
}
//绘制图片的前景干扰点
for (int i = 0; i < 100; i++)
{
int x =
random.Next(newBitmap.Width);
int y =
random.Next(newBitmap.Height);
newBitmap.SetPixel(x, y,
Color.FromArgb(random.Next()));
}
//在最外边绘制边框
g.DrawRectangle(new
Pen(Color.Blue), 0, 0, newBitmap.Width, newBitmap.Height);
g.DrawRectangle(new
Pen(Color.Blue), -1, -1, newBitmap.Width, newBitmap.Height);
//将图转保存到内存流中
MemoryStream ms = new MemoryStream();
newBitmap.Save(ms,ImageFormat.Jpeg);
return ms.ToArray();//将流内容写入byte数组返回
}
}
}