简单生成图片验证码(包括数字大小写字母和汉字)

功能说明:
生成六位随机图片验证码(包括数字 大小写字母 部分汉字)

-------------------------调用代码---------------------------
<asp:Image id="Image1" style="Z-INDEX: 115; LEFT: 368px; POSITION: absolute; TOP: 608px" runat="server"
Width="128px" Height="32px" ImageUrl="code.aspx" onclick="this.src='code.aspx'></asp:Image>
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------------code.aspx.cs文件代码-----------------------


using System;


using System.Collections;


using System.ComponentModel;


using System.Data;


using System.Drawing;


using System.Web;


using System.Web.SessionState;


using System.Web.UI;


using System.Web.UI.WebControls;


using System.Web.UI.HtmlControls;


using System.Drawing.Imaging;


using System.IO;






namespace Bino.WebGB




...{




/**//// <summary>


/// code 的摘要说明。


/// </summary>


public class code : System.Web.UI.Page




...{


private void Page_Load(object sender, System.EventArgs e)




...{


// 在此处放置用户代码以初始化页面


Response.Cache.SetNoStore();


string strNum = Rndnum();


Session["Num"] = strNum;


ValidateCode(strNum);


}






Web 窗体设计器生成的代码#region Web 窗体设计器生成的代码


override protected void OnInit(EventArgs e)




...{


//


// CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。


//


InitializeComponent();


base.OnInit(e);


}






/**//// <summary>


/// 设计器支持所需的方法 - 不要使用代码编辑器修改


/// 此方法的内容。


/// </summary>


private void InitializeComponent()




...{


this.Load += new System.EventHandler(this.Page_Load);




}


#endregion






生成验证码#region 生成验证码


public string Rndnum()




...{


int j1;


string strChoice="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,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,中,长,沙,深,圳,方,广,德,网,络,东,法,家,人,科,技,游,戏,战,国,英,雄,抗";




string [] strResult = strChoice.Split(new Char [] ...{','});


string strReturn = "";


Random rnd = new Random(unchecked((int)DateTime.Now.Ticks));


for(int i=0;i<6;i++)




...{


Random rnd1 = new Random(rnd.Next()*unchecked((int)DateTime.Now.Ticks));


j1 = rnd.Next(85);


rnd = new Random(rnd.Next()*unchecked((int)DateTime.Now.Ticks));


strReturn = strReturn + strResult[j1].ToString();


}


return strReturn;


}




public void ValidateCode(string vnum)




...{


MemoryStream ms = new MemoryStream();


double Height = (vnum.Length) * 15;


int gHeight = Convert.ToInt32(Height);


Bitmap img = new Bitmap(gHeight,20);


Graphics g = Graphics.FromImage(img);


g.DrawString(vnum,(new Font("宋体",13)),(new SolidBrush(Color.Blue)),1,4);


img.Save(ms,ImageFormat.Png);


Response.ClearContent();


Response.ContentType = "image/Bmp";


Response.BinaryWrite(ms.ToArray());


g.Dispose();


Response.End();


}


#endregion


}


}





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