使用实例：
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
verCodeInfo();
}
}
/// <summary>
/// 验证码生成
/// </summary>
private void verCodeInfo()
{
/*方法1*/
VerCodeHelper v = new VerCodeHelper();
Response.Write("<IMG alt=\"" + "" + "\" src=\"data:image/png;base64," + FileHelper.ImgToBase64String(v.Image) + "\" border=\"0\">"); //固定生成长度的验证码
/*方法1*/
/*方法2*/
string chkCode = VerCodeHelper.MakeCode(5); //根据长度自动生成
MemoryStream ms = VerCodeHelper.CreateCodeImg(chkCode);
Response.ClearContent();
Response.ContentType = "image/gif";
Response.BinaryWrite(ms.ToArray());
/*方法2*/
}类库信息：
/// <summary>
/// 验证码生成
/// </summary>
public class VerCodeHelper
{
#region 生成验证码
#region 私有字段
private string text;
private Bitmap image;
private int letterCount = 4; //验证码位数
private int letterWidth = 16; //单个字体的宽度范围
private int letterHeight = 20; //单个字体的高度范围
private static byte[] randb = new byte[4];
private static RNGCryptoServiceProvider rand = new RNGCryptoServiceProvider();
private Font[] fonts =
{
new Font(new FontFamily("Times New Roman"),10 +Next(1),System.Drawing.FontStyle.Regular),
new Font(new FontFamily("Times New Roman"),10 +Next(1),System.Drawing.FontStyle.Regular),
//new Font(new FontFamily("Georgia"), 10 + Next(1),System.Drawing.FontStyle.Regular),
new Font(new FontFamily("Arial"), 10 + Next(1),System.Drawing.FontStyle.Regular),
//new Font(new FontFamily("Comic Sans MS"), 10 + Next(1),System.Drawing.FontStyle.Regular)
new Font(new FontFamily("Arial"), 10 + Next(1),System.Drawing.FontStyle.Regular)
};
#endregion
#region 公有属性
/// <summary>
/// 验证码
/// </summary>
public string Text
{
get { return this.text; }
}
/// <summary>
/// 验证码图片
/// </summary>
public Bitmap Image
{
get { return this.image; }
}
#endregion
#region 构造函数
public VerCodeHelper()
{
HttpContext.Current.Response.Expires = 0;
HttpContext.Current.Response.Buffer = true;
HttpContext.Current.Response.ExpiresAbsolute = DateTime.Now.AddSeconds(-1);
HttpContext.Current.Response.AddHeader("pragma", "no-cache");
HttpContext.Current.Response.CacheControl = "no-cache";
this.text = RandomHelper.Number(4);
CreateImage();
}
#endregion
#region 私有方法
/// <summary>
/// 获得下一个随机数
/// </summary>
/// <param name="max">最大值</param>
private static int Next(int max)
{
rand.GetBytes(randb);
int value = BitConverter.ToInt32(randb, 0);
value = value % (max + 1);
if (value < 0) value = -value;
return value;
}
/// <summary>
/// 获得下一个随机数
/// </summary>
/// <param name="min">最小值</param>
/// <param name="max">最大值</param>
private static int Next(int min, int max)
{
int value = Next(max - min) + min;
return value;
}
#endregion
#region 公共方法
/// <summary>
/// 绘制验证码
/// </summary>
public void CreateImage()
{
int int_ImageWidth = this.text.Length * letterWidth;
Bitmap image = new Bitmap(int_ImageWidth, letterHeight);
Graphics g = Graphics.FromImage(image);
g.Clear(Color.White);
for (int i = 0; i < 2; i++)
{
int x1 = Next(image.Width - 1);
int x2 = Next(image.Width - 1);
int y1 = Next(image.Height - 1);
int y2 = Next(image.Height - 1);
g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);
}
int _x = -12, _y = 0;
for (int int_index = 0; int_index < this.text.Length; int_index++)
{
_x += Next(12, 16);
_y = Next(-2, 2);
string str_char = this.text.Substring(int_index, 1);
str_char = Next(1) == 1 ? str_char.ToLower() : str_char.ToUpper();
Brush newBrush = new SolidBrush(GetRandomColor());
Point thePos = new Point(_x, _y);
g.DrawString(str_char, fonts[Next(fonts.Length - 1)], newBrush, thePos);
}
for (int i = 0; i < 10; i++)
{
int x = Next(image.Width - 1);
int y = Next(image.Height - 1);
image.SetPixel(x, y, Color.FromArgb(Next(0, 255), Next(0, 255), Next(0, 255)));
}
image = TwistImage(image, true, Next(1, 3), Next(4, 6));
g.DrawRectangle(new Pen(Color.LightGray, 1), 0, 0, int_ImageWidth - 1, (letterHeight - 1));
this.image = image;
}
/// <summary>
/// 字体随机颜色
/// </summary>
public Color GetRandomColor()
{
Random RandomNum_First = new Random((int)DateTime.Now.Ticks);
System.Threading.Thread.Sleep(RandomNum_First.Next(50));
Random RandomNum_Sencond = new Random((int)DateTime.Now.Ticks);
int int_Red = RandomNum_First.Next(180);
int int_Green = RandomNum_Sencond.Next(180);
int int_Blue = (int_Red + int_Green > 300) ? 0 : 400 - int_Red - int_Green;
int_Blue = (int_Blue > 255) ? 255 : int_Blue;
return Color.FromArgb(int_Red, int_Green, int_Blue);
}
/// <summary>
/// 正弦曲线Wave扭曲图片
/// </summary>
/// <param name="srcBmp">图片路径</param>
/// <param name="bXDir">如果扭曲则选择为True</param>
/// <param name="nMultValue">波形的幅度倍数，越大扭曲的程度越高,一般为3</param>
/// <param name="dPhase">波形的起始相位,取值区间[0-2*PI)</param>
public System.Drawing.Bitmap TwistImage(Bitmap srcBmp, bool bXDir, double dMultValue, double dPhase)
{
double PI = 6.283185307179586476925286766559;
Bitmap destBmp = new Bitmap(srcBmp.Width, srcBmp.Height);
Graphics graph = Graphics.FromImage(destBmp);
graph.FillRectangle(new SolidBrush(Color.White), 0, 0, destBmp.Width, destBmp.Height);
graph.Dispose();
double dBaseAxisLen = bXDir ? (double)destBmp.Height : (double)destBmp.Width;
for (int i = 0; i < destBmp.Width; i++)
{
for (int j = 0; j < destBmp.Height; j++)
{
double dx = 0;
dx = bXDir ? (PI * (double)j) / dBaseAxisLen : (PI * (double)i) / dBaseAxisLen;
dx += dPhase;
double dy = Math.Sin(dx);
int nOldX = 0, nOldY = 0;
nOldX = bXDir ? i + (int)(dy * dMultValue) : i;
nOldY = bXDir ? j : j + (int)(dy * dMultValue);
Color color = srcBmp.GetPixel(i, j);
if (nOldX >= 0 && nOldX < destBmp.Width
&& nOldY >= 0 && nOldY < destBmp.Height)
{
destBmp.SetPixel(nOldX, nOldY, color);
}
}
}
srcBmp.Dispose();
return destBmp;
}
#endregion
#endregion
#region 根据字符串生成简单验证码
/// <summary>
/// 生成验证码字符串
/// </summary>
/// <param name="codeLen">验证码字符长度</param>
/// <returns>返回验证码字符串</returns>
public static string MakeCode(int codeLen)
{
if (codeLen < 1)
{
return string.Empty;
}
int number;
string checkCode = string.Empty;
Random random = new Random();
for (int index = 0; index < codeLen; index++)
{
number = random.Next();
if (number % 2 == 0)
{
char S = (char)('0' + (char)(number % 10));
if (S == '1' || S == '0')
{
checkCode += "2"; //生成数字
}
else
{
checkCode += S; //生成数字
}
}
else
{
char Z = (char)('A' + (char)(number % 10));
if (Z == 'i' || Z == 'o' || Z == 'I' || Z == 'O')
{
checkCode += 'A'; //生成字母
}
else
{
checkCode += Z; //生成字母
}
}
}
return checkCode;
}
private static Font[] font_Random =
{
new Font(new FontFamily("Times New Roman"),16 +Next(1), (FontStyle.Bold | FontStyle.Italic)),
new Font(new FontFamily("Georgia"), 16 + Next(1), (FontStyle.Bold | FontStyle.Italic)),
new Font(new FontFamily("Arial"), 16 + Next(1), (FontStyle.Bold | FontStyle.Italic)),
new Font(new FontFamily("Comic Sans MS"), 16 + Next(1), (FontStyle.Bold | FontStyle.Italic))
};
///<summary>
/// 获取验证码图片流
/// </summary>
/// <param name="checkCode">验证码字符串</param>
/// <returns>返回验证码图片流</returns>
public static MemoryStream CreateCodeImg(string checkCode)
{
if (string.IsNullOrEmpty(checkCode))
{
return null;
}
Bitmap image = new Bitmap((int)Math.Ceiling((checkCode.Length * 17.0)), 33);
Graphics graphic = Graphics.FromImage(image);
try
{
Random random = new Random();
graphic.Clear(Color.White);
int x1 = 0, y1 = 0, x2 = 0, y2 = 0;
for (int index = 0; index < 25; index++)
{
x1 = random.Next(image.Width);
x2 = random.Next(image.Width);
y1 = random.Next(image.Height);
y2 = random.Next(image.Height);
graphic.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);
}
//Font font = new Font("Arial", 16, (FontStyle.Bold | FontStyle.Italic));
Font font = font_Random[random.Next(0, 4)];
LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Red, Color.DarkRed, 1.2f, true);
graphic.DrawString(checkCode, font, brush, 5, 5);
int x = 0;
int y = 0;
//画图片的前景噪音点
for (int i = 0; i < 100; i++)
{
x = random.Next(image.Width);
y = random.Next(image.Height);
image.SetPixel(x, y, Color.FromArgb(random.Next()));
}
//画图片的边框线
graphic.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
//将图片验证码保存为流Stream返回
System.IO.MemoryStream ms = new System.IO.MemoryStream();
image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
return ms;
}
finally
{
graphic.Dispose();
image.Dispose();
}
}
#endregion
}显示效果：
可以选择不同的生成样式，也可以根据需要调整验证码生成类。
以上类库内容来源互联网，站长稍作整理
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