如何在网页上显示条形码？

调用说明：str为要生成的代码，ch为条形码的高度，cw为条形码单个字符的宽度
另：当type_code为1时，在条形码下显示代码，否则不显示。public string bar_code(object str, int ch, int cw, int type_code){
string strTmp=str.ToString();
string code=strTmp;
strTmp=strTmp.ToLower();
int height=ch;
int width=cw;

strTmp=strTmp.Replace("0", "_|_|__||_||_|");;
strTmp=strTmp.Replace("1", "_||_|__|_|_||");
strTmp=strTmp.Replace("2", "_|_||__|_|_||");
strTmp=strTmp.Replace("3", "_||_||__|_|_|");
strTmp=strTmp.Replace("4", "_|_|__||_|_||");
strTmp=strTmp.Replace("5", "_||_|__||_|_|");
strTmp=strTmp.Replace("7", "_|_|__|_||_||");
strTmp=strTmp.Replace("6", "_|_||__||_|_|");
strTmp=strTmp.Replace("8", "_||_|__|_||_|");
strTmp=strTmp.Replace("9", "_|_||__|_||_|");
strTmp=strTmp.Replace("a", "_||_|_|__|_||");
strTmp=strTmp.Replace("b", "_|_||_|__|_||");
strTmp=strTmp.Replace("c", "_||_||_|__|_|");
strTmp=strTmp.Replace("d", "_|_|_||__|_||");
strTmp=strTmp.Replace("e", "_||_|_||__|_|");
strTmp=strTmp.Replace("f", "_|_||_||__|_|");
strTmp=strTmp.Replace("g", "_|_|_|__||_||");
strTmp=strTmp.Replace("h", "_||_|_|__||_|");
strTmp=strTmp.Replace("i", "_|_||_|__||_|");
strTmp=strTmp.Replace("j", "_|_|_||__||_|");
strTmp=strTmp.Replace("k", "_||_|_|_|__||");
strTmp=strTmp.Replace("l", "_|_||_|_|__||");
strTmp=strTmp.Replace("m", "_||_||_|_|__|");
strTmp=strTmp.Replace("n", "_|_|_||_|__||");
strTmp=strTmp.Replace("o", "_||_|_||_|__|");
strTmp=strTmp.Replace("p", "_|_||_||_|__|");
strTmp=strTmp.Replace("r", "_||_|_|_||__|");
strTmp=strTmp.Replace("q", "_|_|_|_||__||");
strTmp=strTmp.Replace("s", "_|_||_|_||__|");
strTmp=strTmp.Replace("t", "_|_|_||_||__|");
strTmp=strTmp.Replace("u", "_||__|_|_|_||");
strTmp=strTmp.Replace("v", "_|__||_|_|_||");
strTmp=strTmp.Replace("w", "_||__||_|_|_|");
strTmp=strTmp.Replace("x", "_|__|_||_|_||");
strTmp=strTmp.Replace("y", "_||__|_||_|_|");
strTmp=strTmp.Replace("z", "_|__||_||_|_|");
strTmp=strTmp.Replace("-", "_|__|_|_||_||");
strTmp=strTmp.Replace("*", "_|__|_||_||_|");
strTmp=strTmp.Replace("/", "_|__|__|_|__|");
strTmp=strTmp.Replace("%", "_|_|__|__|__|");
strTmp=strTmp.Replace("+", "_|__|_|__|__|");
strTmp=strTmp.Replace(".", "_||__|_|_||_|");
strTmp=strTmp.Replace("_", "<span style='height:"+height+";width:"+width+";background:#FFFFFF;'></span>");
strTmp=strTmp.Replace("|", "<span style='height:"+height+";width:"+width+";background:#000000;'></span>");

if(type_code==1){
return strTmp+"<BR>"+code;
}
else{
return strTmp;
}
}

http://www.programfan.com/showarticle.asp?id=2170

http://www.411asp.net/home/assembly/graphics/barcode

http://www.codeproject.com/bitmap/barcode1.asp
http://www.codeproject.com/bitmap/barcode2.asp

http://www.download.com/ASP-NET-Barcode-Web-Control/3000-7959-10320642.html

using System.Drawing;
using System.Drawing.Imaging;
private void Page_Load(object sender, System.EventArgs e)
  {
   // 在此处放置用户代码以初始化页面
   //RndNum是一个自定义函数
   string VNum=RndNum(4); //这里的数字4代表显示的是4位的验证字符串！
   Session["VNum"]=VNum;
   ValidateCode(VNum);
  }
//生成图像函数
  private void ValidateCode(string VNum)
  {
   int Gheight=(int)(VNum.Length * 11.5);
   //gheight为图片宽度,根据字符长度自动更改图片宽度
   System.Drawing.Bitmap Img = new System.Drawing.Bitmap(Gheight,20);
   Graphics g = Graphics.FromImage(Img);
   g.DrawString(VNum,new System.Drawing.Font("Arial",10),new System.Drawing.SolidBrush(Color.Red),3,3);
   //在矩形内绘制字串（字串，字体，画笔颜色，左上x.左上y）
   System.IO.MemoryStream ms=new System.IO.MemoryStream();
   Img.Save(ms,System.Drawing.Imaging.ImageFormat.Png);
   Response.ClearContent(); //需要输出图象信息要修改HTTP头
   Response.ContentType="image/Png";
   Response.BinaryWrite(ms.ToArray());
   g.Dispose();
   Img.Dispose();
   Response.End();
  }//生成随机数函数中从Vchar数组中随机抽取
//字母区分大小写
public string RndNum(int VcodeNum)
  {
   string Vchar = "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,W,X,Y,Z" ;

   string[] VcArray = Vchar.Split(',') ;
   string  VNum = "" ;//由于字符串很短，就不用StringBuilder了
   int temp = -1 ;//记录上次随机数值，尽量避免生产几个一样的随机数   //采用一个简单的算法以保证生成随机数的不同
   Random rand =new Random();
   for ( int i = 1 ; i < VcodeNum+1 ; i++ )
   {
    if ( temp != -1)
    {
     rand =new Random(i*temp*unchecked((int)DateTime.Now.Ticks));
    }
    //int t =  rand.Next(35) ;
    int t=rand.Next(35);
    if (temp != -1 && temp == t)
    {
     return RndNum( VcodeNum );
    }
    temp = t  ;
    VNum += VcArray[t];   }
   return VNum ;
  }
-----------------------------------end--------------------------------------------下面是Login.Aspx在在调用提交按钮的响应事件中
public void doit(object sender, System.EventArgs e)
  {
   if(Page.IsValid)
   {

    string VNum;
    VNum=Session["VNum"].ToString();
    Session.Abandon();
    ViewState["VNum"]=VNum;
    if(this.Vcode.Text==ViewState["VNum"].ToString())
    {      Hover.Manage.CheckLogin obj=new Hover.Manage.CheckLogin();
     string name=username.Text;
     string password=FormsAuthentication.HashPasswordForStoringInConfigFile(pass.Text.ToString(),"md5");
     if(!obj.checklogin(name,password))
     {
      Response.Redirect("../Error.aspx?action=Errorlogin");
      Response.End();
      return;
     }
     else
     {
      Session.Add("adminname",name);
      Session.Add("adminpass",password);
      Response.Redirect("Default.aspx");
      Response.End();
      return;
     }

    }
    else
    {
     Response.Write("<script>alert(\"请输入正确的附加码！\");</script>");
    }
   }
  }
   如果提交过来的验证字符串正确就验证是否是合法用户！
否则弹出提示返回登陆页!你也可以简化此页!
   if(this.Vcode.Text==ViewState["VNum"].ToString())
    {
        Response.Write("验证码正确");
    }
   else
    {
        Response.Write("验证码错误!");
    }

还有一种方法在web页面上画出条码的代码            Dim sn As String = Request.QueryString("SN")
            Dim StockBitMap As Bitmap
            Dim memStream As New MemoryStream
            If sn = "" Then Return
            sn = sn.ToUpper
            ' sn =
            Response.ContentType = "image/png"
            StockBitMap = New Bitmap(130, 60)
            Dim graph As Graphics = Nothing
            graph = Graphics.FromImage(StockBitMap)
            graph.CompositingQuality = CompositingQuality.HighQuality
            graph.SmoothingMode = SmoothingMode.AntiAlias
            Dim pfc As PrivateFontCollection = New PrivateFontCollection
           '载入字体                     pfc.AddFontFile(Server.MapPath("font/V100010_.TTF"))
            Dim fm As New FontFamily("C39HrP48DlTt", pfc)
            Dim f As New Font(fm, 40)
            graph.Clear(Color.White)
            graph.DrawString("*" & sn & "*", f, New SolidBrush(Color.Black), 0, 0)
            StockBitMap.Save(memStream, ImageFormat.Png)
            memStream.WriteTo(Response.OutputStream)

Microsoft CodeBar Control 9.0
好像不支持b/s

调试易

如何在网页上显示条形码？

解决方案 »