知识大全 ASP.NET 做验证码

Posted 2022-07-17 知

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　　显示验证码的界面前台 <td class= style > 验证码 </td> <td class= style > <asp:TextBox ID= TextBox runat= server Height= px ></asp:TextBox> <asp:Image ID= Image runat= server ImageUrl= ~/Default aspx />  <asp:HyperLink ID= HyperLink runat= server NavigateUrl= ~/Default aspx >看不清换张图</asp:HyperLink> </td>后台 using System;using System Collections Generic;using System Linq;using System Web;using System Web UI;using System Web UI WebControls;using System Data;using System Data SqlClient;using System Configuration;public partial class _Default : System Web UI Page protected void Page_Load(object sender EventArgs e)

　　 protected void Button _Click(object sender EventArgs e) string str = ConfigurationManager ConnectionStrings[ sqlstr ] ConnectionString; using (SqlConnection sqlCnn=new SqlConnection(str)) using (SqlCommand sqlCmm=sqlCnn CreateCommand()) sqlCmm CommandText = select * from Login ; sqlCnn Open(); SqlDataReader reader = sqlCmm ExecuteReader(); bool bl = false; if (reader!=null) while (reader Read()) if (this TextBox Text == reader[ name ] ToString() && this TextBox Text == reader[ password ] ToString() && this TextBox Text == Session[ code ] ToString()) bl = true; if (bl==true) ClientScript RegisterClientScriptBlock(GetType() 提示 <script>alert( 登陆成功！ )</script> ); else ClientScript RegisterClientScriptBlock(GetType() 提示 <script>alert( 登陆失败！ )</script> ); 做验证码的界面 using System;using System Collections Generic;using System Linq;using System Web;using System Web UI;using System Web UI WebControls;using System Drawing;using System IO;using System Text;public partial class Default : System Web UI Page protected void Page_Load(object sender EventArgs e) System Drawing Image img = new Bitmap( ); Graphics g = Graphics FromImage(img); this DealImage(img ); g DrawLine(Pens Yellow ); string code = this GenerateCode();

　　Font font = new Font( 宋体 FontStyle Bold | FontStyle Italic | FontStyle Strikeout | FontStyle Underline); Session[ code ] = code; //保存到Session中 g DrawString(code font Brushes YellowGreen ); this Response Clear(); MemoryStream ms = new MemoryStream(); img Save(ms System Drawing Imaging ImageFormat Jpeg); this Response BinaryWrite(ms ToArray()); this Response Flush(); this Response End();

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