做登陆页面的随机验证码

来源：互联网发布：vue.js 图片点击放大编辑：程序博客网时间：2024/05/19 19:34

先放上这页代码：（radamdata.aspx是用来产生验证码图片用的)

Imports System.Drawing

Imports System.IO

Partial Class test2

Inherits System.Web.UI.Page

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

' 在此处放置用户代码以初始化页面

If Not Page.IsPostBack Then

Me.GenImg(Me.GenCode(4))

End If

End Sub

Private Function GenCode(ByVal num As Integer) As String

Dim [source] As String() = {"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"}

Dim code As String = ""

Dim rd As New Random()

Dim i As Integer

For i = 0 To num - 1

code += [source](rd.Next(0, [source].Length))

Next i

Return code

End Function 'GenCode

'生成图片

Private Sub GenImg(ByVal code As String)

Dim myPalette As New Bitmap(60, 20) '定义一个画板

Dim gh As Graphics = Graphics.FromImage(myPalette) '在画板上定义绘图的实例

Dim rc As New Rectangle(0, 0, 60, 20) '定义一个矩形

gh.FillRectangle(New SolidBrush(Color.Silver), rc) '填充矩形

gh.DrawString(code, New Font("宋体", 16), New SolidBrush(Color.Gray), rc) '在矩形内绘制字串（字串，字体，画笔颜色，左上x.左上y）

myPalette.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg) '将图片显示出来

'下面这些也是将图片显示出来的！

'Dim ms As MemoryStream = New MemoryStream

'myPalette.Save(ms, Imaging.ImageFormat.Jpeg)

' Response.ClearContent()

' Response.ContentType = "image/jpeg"

' Response.BinaryWrite(ms.ToArray)

Session("ValidateCode") = code '将字符串保存到Session中，以便需要时进行验证

gh.Dispose()

myPalette.Dispose()

End Sub 'GenImg

End Class

..................................................................................................................................................................

放上调用radamdata.aspx的radamindex.aspx的代码

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

End Sub

Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click

If TextBox1.Text = Session("ValidateCode") Then

Label1.Text = "haha,你成功了！！！"

Else

Label1.Text = "不对哦"

End If

End Sub

End Class

然后在randamindex.aspx上放一个image控件，使他的图片连接为randamdata.aspx就行了！！！