NET 很简单的一个生成随机验证码封装的一个类-优快云博客

本文介绍了一个简单的验证码生成器实现，该生成器可以生成指定长度的随机字符串验证码，并将其绘制在一张图片上，同时还介绍了如何将验证码字符串保存在Session中以便后续验证。

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usingSystem;

usingSystem.Data;

usingSystem.Configuration;

usingSystem.Web;

usingSystem.Web.Security;

usingSystem.Web.UI;

usingSystem.Web.UI.WebControls;

usingSystem.Web.UI.WebControls.WebParts;

usingSystem.Web.UI.HtmlControls;

usingSystem.Drawing;

///<summary> 

///VerifyCode的摘要说明产生随机数 

///</summary> 

publicclassVerifyCode
{

publicVerifyCode()
{
}

//产生随机字符串 

///<summary> 

///产生随机数 

///</summary> 

///<paramname="num">需要的字符的个数</param> 

///<returns>返回产生的随机数</returns> 

publicstringGenCode(intnum)
{

//定义一个数组 

string[]source={"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","V","W","X","Y","Z"};

//定义一个装数组的字符串 

stringcode="";

Randomrd=newRandom();

for(inti=0;i<num;i++)
{
code+=source[rd.Next(0,source.Length)];
}

returncode;//返回产生的随机数 
}

//生成图片 

publicvoidGenImg(stringcode,PagecurPage)
{

BitmapmyPalette=newBitmap(60,20);//定义一个画板 

Graphicsgh=Graphics.FromImage(myPalette);//在画板上定义绘图的实例 

Rectanglerc=newRectangle(0,0,60,20);//定义一个矩形 

gh.FillRectangle(newSolidBrush(Color.Blue),rc);//填充矩形 

gh.DrawString(code,newFont("宋体",16),newSolidBrush(Color.White),rc);//在矩形内画出字符串 

myPalette.Save(curPage.Response.OutputStream,System.Drawing.Imaging.ImageFormat.Jpeg);//将图片显示出来 

curPage.Session["ValidateCode"]=code;//将字符串保存到Session中，以便需要时进行验证 

gh.Dispose();//关闭　 
myPalette.Dispose();
}
}