Simple production of asp.net verification code

In fact, there are already many articles about the production of asp.net verification code, but today I still want to share it with you. Dear, you can combine several examples to write an ASP.NET verification code suitable for your own website, probably There are only two parts:

First create an asp.net form ValidateCode.aspx; do not write anything. Write the following code directly in the background ValidateCode.aspx.cs:

protected void Page_Load(object sender, EventArgs e)
{
  string validateCode = CreateValidateCode();//生成验证码
  Bitmap bitmap = new Bitmap(imgWidth,imgHeight);//生成Bitmap图像
  DisturbBitmap(bitmap); //图像背景
  DrewValidateCode(bitmap,validateCode);//绘制验证码图像
  bitmap.Save(Response.OutputStream,ImageFormat.Gif);//保存图像，等待输出

}

private int codeLen = 4;//验证码长度
private int fineness = 85;//图片清晰度
private int imgWidth = 48;//图片宽度
private int imgHeight = 24;//图片高度
private string fontFamily = "Times New Roman";//字体名称
private int fontSize = 14;//字体大小
//private int fontStyle = 0;//字体样式
private int posX = 0;//绘制起始坐标X
private int posY = 0;//绘制坐标Y
private string CreateValidateCode() //生成验证码
{
  string validateCode = "";
  Random random = new Random();// 随机数对象
  for (int i = 0; i < codeLen; i++)//循环生成每位数值
  {
    int n = random.Next(10);//数字
    validateCode += n.ToString();
  }
  Session["vcode"] = validateCode;//保存验证码 这Session是在前台调用的。
  return validateCode;// 返回验证码
}

private void DisturbBitmap(Bitmap bitmap)//图像背景
{
  Random random = new Random();//通过随机数生成
  for (int i = 0; i < bitmap.Width; i++)//通过循环嵌套，逐个像素点生成
  {
    for (int j = 0; j < bitmap.Height; j++)
    {
      if (random.Next(90) <= this.fineness)
        bitmap.SetPixel(i, j, Color.LightGray);
    }
  }
}
private void DrewValidateCode(Bitmap bitmap, string validateCode)//绘制验证码图像
{
  Graphics g = Graphics.FromImage(bitmap);//获取绘制器对象
  Font font = new Font(fontFamily, fontSize, FontStyle.Bold);//设置绘制字体
  g.DrawString(validateCode, font, Brushes.Black, posX, posY);//绘制验证码图像
}

Login.aspx form front desk:

//这个函数是在点击验证码图片就会更换验证码
//可以使用微软自带的jqury.js 下面jquery-1.4.1.min.js版本之上的。或者在jquery官网上下载就可以。
 <script src="styles/jquery-1.4.1.min.js" type="text/javascript"></script>
     function f_refreshtype() {
       var Image1 = document.getElementByIdx_x_x_x("img");
       if (Image1 != null) {
         Image1.src = Image1.src + "?";
       }
     }
---<img src="ValidateCode.aspx" id="img" onclick="f_refreshtype()" width="50px"/>//调用函数，实现更换验证码

Backend code: Click login to verify whether the user input is correct .

string usercode = txtcode.Text.Trim();
    if (usercode == Session["vcode"].ToString())//Session["vcode"]
    {
}

Other codes are the same as others.

The above is the process of generating ASP.NET verification code shared with you. I hope you can apply what you have learned.

For more articles related to the simple production of asp.net verification codes, please pay attention to the PHP Chinese website!