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 codeWeb Form Designer generated code#region Web Form Designer generated code override protected void OnInit(EventArgs e) { // // CODEGEN: This call is required by the ASP.NET Web Form Designer. // InitializeComponent(); base.OnInit(e); } /**//**//**//// <summary> /// Required method for Designer support - do not modify /// the contents of this method with the code editor. /// </summary> private void InitializeComponent() { this.Load += new System.EventHandler(this.Page_Load); } #endregion 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
<HTML> <HEAD> <title>Login</title> <meta name="GENERATOR" Content="Microsoft Visual Studio .NET 7.1"> <meta name="CODE_LANGUAGE" Content="C#"> <meta name="vs_defaultClientScript" content="JavaScript"> <meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5"> </HEAD> <body> <form id="Form1" method="post" runat="server"> <table align="center" cellSpacing="0" cellPadding="0" width="100%" border="0" height="100%"> <colgroup> <col width="30%"> </col> <col width="40%"> </col> <col width="30%"> </col> </colgroup> <tr> <td></td> <td valign="middle"> <TABLE id="Table1" align="center" cellSpacing="0" cellPadding="0" width="100%" border="0"> <colgroup> <col width="20%"> </col> <col width="35%"> </col> <col width="25%"> </col> <col width="20%"> </col> </colgroup> <TR> <TD align="right">LoginName</TD> <TD> <asp:TextBox id="txtLoginName" runat="server" Width="100%"></asp:TextBox></TD> <td></td> <td></td> </TR> <TR> <TD align="right">Password</TD> <TD> <asp:TextBox id="txtPassword" runat="server" Width="100%"></asp:TextBox></TD> <td></td> <td></td> </TR> <TR> <TD align="right">ValidateCode</TD> <TD> <asp:TextBox id="txtValidateCode" runat="server" Width="100%"></asp:TextBox></TD> <td><IMG alt="" src="Pages/Wonderful/Form/ValidateCode.aspx"></td> <td></td> </TR> <TR> <TD></TD> <TD> <asp:Button id="Login" runat="server" Text="Login"></asp:Button> <asp:Button id="Reset" runat="server" Text="Reset"></asp:Button></TD> <td></td> <td></td> </TR> </TABLE> </td> <td></td> </tr> </table> </form> </body></HTML>3.Login页面的cs代码
public class Login : System.Web.UI.Page{ protected System.Web.UI.WebControls.TextBox txtLoginName; protected System.Web.UI.WebControls.TextBox txtPassword; protected System.Web.UI.WebControls.TextBox txtValidateCode; protected System.Web.UI.WebControls.Button Login; protected System.Web.UI.WebControls.Button Reset; protected System.Web.UI.WebControls.TextBox TextBox1;private void Page_Load(object sender, System.EventArgs e) { if(Session["VNum"]!=null && Session["VNum"].ToString()==txtValidateCode.Text) { //验证码正确 } } Web Form Designer generated codeWeb Form Designer generated code#region Web Form Designer generated code override protected void OnInit(EventArgs e) { // // CODEGEN: This call is required by the ASP.NET Web Form Designer. // InitializeComponent(); base.OnInit(e); } /**//**//**//// <summary> /// Required method for Designer support - do not modify /// the contents of this method with the code editor. /// </summary> private void InitializeComponent() { this.Load += new System.EventHandler(this.Page_Load); } #endregion}
