验证码类
namespace qjw.verifycode
{
//用法：
//public filecontentresult createvalidate()
//{
// validatecode vcode = new validatecode();
// string code = vcode.createvalidatecode(5);
// session["validatecode"] = code;
// byte[] bytes = vcode.createvalidategraphic(code);
// return file(bytes, "image/jpeg");
//}
public class validatecode
{
public validatecode()
{
}
/// <summary>
/// 验证码的最大长度
/// </summary>
public int maxlength
{
get { return 10; }
}
/// <summary>
/// 验证码的最小长度
/// </summary>
public int minlength
{
get { return 1; }
}
/// <summary>
/// 生成验证码
/// </summary>
/// <param name="length">指定验证码的长度</param>
/// <returns></returns>
public string createvalidatecode(int length)
{
int[] randmembers = new int[length];
int[] validatenums = new int[length];
string validatenumberstr = "";
//生成起始序列值
int seekseek = unchecked((int)datetime.now.ticks);
random seekrand = new random(seekseek);
int beginseek = (int)seekrand.next(0, int32.maxvalue - length * 10000);
int[] seeks = new int[length];
for (int i = 0; i < length; i++)
{
beginseek += 10000;
seeks[i] = beginseek;
}
//生成随机数字
for (int i = 0; i < length; i++)
{
random rand = new random(seeks[i]);
int pownum = 1 * (int)math.pow(10, length);
randmembers[i] = rand.next(pownum, int32.maxvalue);
}
//抽取随机数字
for (int i = 0; i < length; i++)
{
string numstr = randmembers[i].tostring();
int numlength = numstr.length;
random rand = new random();
int numposition = rand.next(0, numlength - 1);
validatenums[i] = int32.parse(numstr.substring(numposition, 1));
}
//生成验证码
for (int i = 0; i < length; i++)
{
validatenumberstr += validatenums[i].tostring();
}
return validatenumberstr;
}
/// <summary>
/// 创建验证码的图片
/// </summary>
/// <param name="containspage">要输出到的page对象</param>
/// <param name="validatenum">验证码</param>
public byte[] createvalidategraphic(string validatecode)
{
bitmap image = new bitmap((int)math.ceiling(validatecode.length * 12.0), 22);
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", 12, (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();
}
}
/// <summary>
/// 得到验证码图片的长度
/// </summary>
/// <param name="validatenumlength">验证码的长度</param>
/// <returns></returns>
public static int getimagewidth(int validatenumlength)
{
return (int)(validatenumlength * 12.0);
}
/// <summary>
/// 得到验证码的高度
/// </summary>
/// <returns></returns>
public static double getimageheight()
{
return 22.5;
}
}
}
使用方法
public filecontentresult createvalidate()
{
validatecode vcode = new validatecode();
string code = vcode.createvalidatecode(5);
session["validatecode"] = code;
byte[] bytes = vcode.createvalidategraphic(code);
return file(bytes, "image/jpeg");
}
html
<a href="javascript:;" onclick="reloadcode();"><img id="safecode" src="/common/createvalidate" alt="" /></a>
视图js
function reloadcode() {
var verify = document.getelementbyid('safecode');
verify.setattribute('src', '/common/createvalidate?' + math.random());
}
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。
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