先建一张生成验证码的网页CheckCode.aspx:
CheckCode.aspx.cs代码如下
添加引用:using System.IO;
using System.Drawing;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;
public partial class Default2 : System.Web.UI.Page
{
private Bitmap validateimage;
private Graphics g;
protected void Page_Load(object sender, EventArgs e)
{
Response.BufferOutput = true; //特别注意
Response.Cache.SetExpires(DateTime.Now.AddMilliseconds(-1));//特别注意
Response.Cache.SetCacheability(HttpCacheability.NoCache);//特别注意
Response.AppendHeader(" Pragma", "No-Cache"); //特别注意
string VNum = MakeValidateCode();
Session["VNum"] = VNum;//取得验证码,以便后来验证
ValidateCode(VNum);
}
public void ValidateCode(string VNum)
{
validateimage = new Bitmap(60, 20, PixelFormat.Format24bppRgb);
g = Graphics.FromImage(validateimage);
g.FillRectangle(new LinearGradientBrush(new Point(0, 0), new Point(110, 20), Color.FromArgb(240, 255, 255, 255), Color.FromArgb(240, 255, 255, 255)), 0, 0, 200, 200); //矩形框
g.DrawString(VNum, new Font("arial", 11), new SolidBrush(Color.Red), new PointF(6, 0));//字体/颜色
g.Save();
MemoryStream ms = new MemoryStream();
validateimage.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
Response.ClearContent();
Response.C;
Response.BinaryWrite(ms.ToArray());
Response.End();
}
string MakeValidateCode()
{
char[] s = new char[] { '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','P','Q','I','S','T','U','V','W','X','Y','Z'};//枚举数组
string num = "";
Random r = new Random();
for (int i = 0; i < 5; i++)
{
num += s[r.Next(0, s.Length)].ToString();
}
return num;
}
}然后是显示验证码的页面 的html中加入
<asp:TextBox ID="in_text" runat="server" onblur="test_number()"></asp:TextBox>
<img src="CheckCode.aspx" id="yzm" alt="点击刷新" />
<asp:Label ID="Label1" runat="server" Text="看不清" onclick="reloadcode()"></asp:Label>
<img src="images/accepted.png" style="display:none" id="sucess5" />
<asp:Label ID="Label2" runat="server" Text=""></asp:Label>
在</head>之前一行加入javascript脚本语言如下(当然写在JS文件里面更好):
<script type="text/javascript">
function reloadcode(){
document.getElementById("yzm").src ="CheckCode.aspx";
}
</script>html引用的js文件如下:
//验证码验证
function test_number() {
var input_number = document.getElementById("in_text");
var vnum = '<%=Session["VNum"]%>';
if (input_number.value =="")
{
document.getElementById("sucess5").style.display = "none";
document.getElementById("Label2").innerHTML= "请输入正确的验证码";
}
if (input_number.value == vnum)
{
document.getElementById("sucess5").style.display = "block";
document.getElementById("Label2").innerHTML = "";
}
if (input_number.value != vnum)
{
document.getElementById("sucess5").style.display = "none";
document.getElementById("yzm").src = "CheckCode.aspx";
// document.getElementById("Label2").innerHTML = "请输入正确的验证码";
}
} 问题:我现在输入了正确的验证码之后它还是刷新提示错误,我真的不知道哪里有问题了,请高手帮忙看一下吧...
CheckCode.aspx.cs代码如下
添加引用:using System.IO;
using System.Drawing;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;
public partial class Default2 : System.Web.UI.Page
{
private Bitmap validateimage;
private Graphics g;
protected void Page_Load(object sender, EventArgs e)
{
Response.BufferOutput = true; //特别注意
Response.Cache.SetExpires(DateTime.Now.AddMilliseconds(-1));//特别注意
Response.Cache.SetCacheability(HttpCacheability.NoCache);//特别注意
Response.AppendHeader(" Pragma", "No-Cache"); //特别注意
string VNum = MakeValidateCode();
Session["VNum"] = VNum;//取得验证码,以便后来验证
ValidateCode(VNum);
}
public void ValidateCode(string VNum)
{
validateimage = new Bitmap(60, 20, PixelFormat.Format24bppRgb);
g = Graphics.FromImage(validateimage);
g.FillRectangle(new LinearGradientBrush(new Point(0, 0), new Point(110, 20), Color.FromArgb(240, 255, 255, 255), Color.FromArgb(240, 255, 255, 255)), 0, 0, 200, 200); //矩形框
g.DrawString(VNum, new Font("arial", 11), new SolidBrush(Color.Red), new PointF(6, 0));//字体/颜色
g.Save();
MemoryStream ms = new MemoryStream();
validateimage.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
Response.ClearContent();
Response.C;
Response.BinaryWrite(ms.ToArray());
Response.End();
}
string MakeValidateCode()
{
char[] s = new char[] { '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','P','Q','I','S','T','U','V','W','X','Y','Z'};//枚举数组
string num = "";
Random r = new Random();
for (int i = 0; i < 5; i++)
{
num += s[r.Next(0, s.Length)].ToString();
}
return num;
}
}然后是显示验证码的页面 的html中加入
<asp:TextBox ID="in_text" runat="server" onblur="test_number()"></asp:TextBox>
<img src="CheckCode.aspx" id="yzm" alt="点击刷新" />
<asp:Label ID="Label1" runat="server" Text="看不清" onclick="reloadcode()"></asp:Label>
<img src="images/accepted.png" style="display:none" id="sucess5" />
<asp:Label ID="Label2" runat="server" Text=""></asp:Label>
在</head>之前一行加入javascript脚本语言如下(当然写在JS文件里面更好):
<script type="text/javascript">
function reloadcode(){
document.getElementById("yzm").src ="CheckCode.aspx";
}
</script>html引用的js文件如下:
//验证码验证
function test_number() {
var input_number = document.getElementById("in_text");
var vnum = '<%=Session["VNum"]%>';
if (input_number.value =="")
{
document.getElementById("sucess5").style.display = "none";
document.getElementById("Label2").innerHTML= "请输入正确的验证码";
}
if (input_number.value == vnum)
{
document.getElementById("sucess5").style.display = "block";
document.getElementById("Label2").innerHTML = "";
}
if (input_number.value != vnum)
{
document.getElementById("sucess5").style.display = "none";
document.getElementById("yzm").src = "CheckCode.aspx";
// document.getElementById("Label2").innerHTML = "请输入正确的验证码";
}
} 问题:我现在输入了正确的验证码之后它还是刷新提示错误,我真的不知道哪里有问题了,请高手帮忙看一下吧...
var input_number = document.getElementById("in_text");
var vnum = '<%=Session["VNum"]%>';
alert(vnum);//弹出来看下是什么,把单引号换成双引号试试
还有像这种验证建议都改用AJAX验证来做吧
var vnum = '<%=Session["VNum"]%>';这个时候vnum 取到的值是 生成页面的那一刻 session里面的值(是什么值我们不管)但是你验证图片访问后台时 又生产成了新的 验证码值 这个时候后台的这个值没传给前台的vnum吧