登陆验证码简单制作
1.建立ValidateCode.aspx页面cs代码
public class ValidateCode : System.Web.UI.Page
{
private void Page_Load(object sender, System.EventArgs e)
{
//如果要在页面a.aspx生成验证码，则在该页面添加一个图片控件，假设命名为：Image1，然后在page_Load事件中写如下代码：
//ImageButton1.ImageUrl = "ValidateCode.aspx";
//这样就可以生成验证码了，ValidateCode.aspx页面可以随便放在哪里，不过要注意Image1.src 要写对，同级可以直接写ValidateCode.aspx，上一级写../ValidateCode.aspx，很方便吧。
if(!IsPostBack)
{
//RndNum是一个自定义函数
//这里的数字4代表显示的是4位的验证字符串！
//string VNum=RndNum(4);
string VNum=GenerateRandom(4);
Session["VNum"] = VNum;
Validate_Code(VNum);
}
}
Web Form Designer generated code
private void Validate_Code(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();
}
private static char[] constant=
{
'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'
};
public static string GenerateRandom(int Length)
{
System.Text.StringBuilder newRandom = new System.Text.StringBuilder(62);
Random rd= new Random();
for(int i=0;i<Length;i++)
{
newRandom.Append(constant[rd.Next(62)]);
}
return newRandom.ToString();
}
}
2.建立演示页面Login.aspx,html代码
1 <HTML> 2 <HEAD> 3 <title>Login</title> 4 <meta name="GENERATOR" Content="Microsoft Visual Studio .NET 7.1"> 5 <meta name="CODE_LANGUAGE" Content="C#"> 6 <meta name="vs_defaultClientScript" content="JavaScript"> 7 <meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5"> 8 </HEAD> 9 <body> 10 <form id="Form1" method="post" runat="server"> 11 <table align="center" cellSpacing="0" cellPadding="0" width="100%" border="0" height="100%"> 12 <colgroup> 13 <col width="30%"> 14 </col> 15 <col width="40%"> 16 </col> 17 <col width="30%"> 18 </col> 19 </colgroup> 20 <tr> 21 <td></td> 22 <td valign="middle"> 23 <TABLE id="Table1" align="center" cellSpacing="0" cellPadding="0" width="100%" border="0"> 24 <colgroup> 25 <col width="20%"> 26 </col> 27 <col width="35%"> 28 </col> 29 <col width="25%"> 30 </col> 31 <col width="20%"> 32 </col> 33 </colgroup> 34 <TR> 35 <TD align="right">LoginName</TD> 36 <TD> 37 <asp:TextBox id="txtLoginName" runat="server" Width="100%"></asp:TextBox></TD> 38 <td></td> 39 <td></td> 40 </TR> 41 <TR> 42 <TD align="right">Password</TD> 43 <TD> 44 <asp:TextBox id="txtPassword" runat="server" Width="100%"></asp:TextBox></TD> 45 <td></td> 46 <td></td> 47 </TR> 48 <TR> 49 <TD align="right">ValidateCode</TD> 50 <TD> 51 <asp:TextBox id="txtValidateCode" runat="server" Width="100%"></asp:TextBox></TD> 52 <td><IMG alt="" src="Pages/Wonderful/Form/ValidateCode.aspx"></td> 53 <td></td> 54 </TR> 55 <TR> 56 <TD></TD> 57 <TD> 58 <asp:Button id="Login" runat="server" Text="Login"></asp:Button> 59 <asp:Button id="Reset" runat="server" Text="Reset"></asp:Button></TD> 60 <td></td> 61 <td></td> 62 </TR> 63 </TABLE> 64 </td> 65 <td></td> 66 </tr> 67 </table> 68 </form> 69 </body> 70 </HTML>
3.Login页面的cs代码
public class Login : System.Web.UI.Page{
protected System.Web.UI.WebControls.TextBox txtLoginName;
{
}
}
