江西公共资源交易网,可外链的相册,在线万年历
1、复制下列代码，拷贝到控制器中。
我要评论#region 生成验证码图片
// [outputcache(location = outputcachelocation.none, duration = 0, nostore = false)]
public actionresult securitycode()
{
string oldcode = session["securitycode"] as string;
string code = createrandomcode(5);
session["securitycode"] = code;
return file(createvalidategraphic(code), "image/jpeg");
}
private byte[] createimage(string checkcode)
{
int iwidth = (int)(checkcode.length * 12);
system.drawing.bitmap image = new system.drawing.bitmap(iwidth, 20);
graphics g = graphics.fromimage(image);
font f = new system.drawing.font("arial", 10, system.drawing.fontstyle.bold);
brush b = new system.drawing.solidbrush(color.white);
g.clear(color.blue);
g.drawstring(checkcode, f, b, 3, 3);
pen blackpen = new pen(color.black, 0);
random rand = new random();
for (int i = 0; i < 5; i++)
{
int x1 = rand.next(image.width);
int x2 = rand.next(image.width);
int y1 = rand.next(image.height);
int y2 = rand.next(image.height);
g.drawline(new pen(color.silver, 1), x1, y1, x2, y2);
}
system.io.memorystream ms = new system.io.memorystream();
image.save(ms, system.drawing.imaging.imageformat.jpeg);
return ms.toarray();
}
private string createrandomcode(int codecount)
{
string allchar = "0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,w,x,y,z";
string[] allchararray = allchar.split(',');
string randomcode = "";
int temp = -1;
random rand = new random();
for (int i = 0; i < codecount; i++)
{
if (temp != -1)
{
rand = new random(i * temp * ((int)datetime.now.ticks));
}
int t = rand.next(35);
if (temp == t)
{
return createrandomcode(codecount);
}
temp = t;
randomcode += allchararray[t];
}
return randomcode;
}
/// <summary>
/// 创建验证码的图片
/// </summary>
public byte[] createvalidategraphic(string validatecode)
{
bitmap image = new bitmap((int)math.ceiling(validatecode.length * 16.0), 27);
graphics g = graphics.fromimage(image);
try
{
//生成随机生成器
random random = new random();
//清空图片背景色
g.clear(color.white);
//画图片的干扰线
for (int i = 0; i < 25; i++)
{
int x1 = random.next(image.width);
int x2 = random.next(image.width);
int y1 = random.next(image.height);
int y2 = random.next(image.height);
g.drawline(new pen(color.silver), x1, y1, x2, y2);
}
font font = new font("arial", 13, (fontstyle.bold | fontstyle.italic));
lineargradientbrush brush = new lineargradientbrush(new rectangle(0, 0, image.width, image.height),
color.blue, color.darkred, 1.2f, true);
g.drawstring(validatecode, font, brush, 3, 2);
//画图片的前景干扰点
for (int i = 0; i < 100; i++)
{
int x = random.next(image.width);
int y = random.next(image.height);
image.setpixel(x, y, color.fromargb(random.next()));
}
//画图片的边框线
g.drawrectangle(new pen(color.silver), 0, 0, image.width - 1, image.height - 1);
//保存图片数据
memorystream stream = new memorystream();
image.save(stream, imageformat.jpeg);
//输出图片流
return stream.toarray();
}
finally
{
g.dispose();
image.dispose();
}
}
#endregion
2、复制以下图片标记到视图中
<img src="/控制器的名字/securitycode" onclick="this.src+='?new date()'" />
3、验证方式，使用 session["securitycode"] 判断填写的是否相等，txtcode自己输入的验证码。
if (session["securitycode"] .tostring().tolower() != txtcode.tolower())
{
response.write("<script>alert('验证码错误')</script>");
}
else
{
}
如对本文有疑问，请在下面进行留言讨论，广大热心网友会与你互动！！ 点击进行留言回复
Net Core Web Api项目与在NginX下发布的方法
asp.net core3.1 引用的元包dll版本兼容性问题解决方案
IdentityServer4实现.Net Core API接口权限认证(快速入门)
ASP.NET Core MVC通过IViewLocationExpander扩展视图搜索路径的实现
网友评论