checkcode.aspx.vb

asp.net一个验证程序,这个是用VB.net写的,您有什么疑问请发送邮件到[e-mail]

Imports System.Collections
Imports System.ComponentModel
Imports System.Drawing

Public Class CheckCode
    Inherits System.Web.UI.Page

#Region " Web 窗体设计器生成的代码 "

    '该调用是 Web 窗体设计器所必需的。
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()

    End Sub

    '注意: 以下占位符声明是 Web 窗体设计器所必需的。
    '不要删除或移动它。
    Private Rum As Pub3one = New Pub3one
    Private designerPlaceholderDeclaration As System.Object

    Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init
        'CODEGEN: 此方法调用是 Web 窗体设计器所必需的
        '不要使用代码编辑器修改它。
        InitializeComponent()
    End Sub

#End Region

    Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        '在此处放置初始化页的用户代码
        Dim str As String = Rum.RndNum(5)
        CreateCheckCodeImage(str)
        Session("checknum") = str
    End Sub

    Private Function CreateCheckCodeImage(ByVal checkCode As String)
        If (checkCode = "" Or checkCode.Trim() = "") Then

        End If
        Dim Image As Bitmap = New Bitmap(CInt(Math.Ceiling((checkCode.Length * 12.5))), 22)
        Dim g As Graphics = Graphics.FromImage(Image)

        Try
            '生成随机生成器
            Dim random As Random = New Random

            '清空图片背景色
            g.Clear(Color.White)

            '画图片的背景噪音线
            Dim i As Integer
            For i = 0 To 25
                Dim x1 As Integer = random.Next(Image.Width)
                Dim x2 As Integer = random.Next(Image.Width)
                Dim y1 As Integer = random.Next(Image.Height)
                Dim y2 As Integer = random.Next(Image.Height)

                g.DrawLine(New Pen(Color.Silver), x1, y1, x2, y2)
            Next

            Dim font As Font = New Font("Arial", 12, (System.Drawing.FontStyle.Bold Or System.Drawing.FontStyle.Italic))
            Dim brush As Drawing2D.LinearGradientBrush = New Drawing2D.LinearGradientBrush(New Rectangle(0, 0, Image.Width, Image.Height), Color.Blue, Color.DarkRed, 1.2F, True)
            g.DrawString(checkCode, font, brush, 2, 2)

            '画图片的前景噪音点
            Dim i2 As Integer
            For i2 = 0 To 100

                Dim x As Integer = random.Next(Image.Width)
                Dim y As Integer = random.Next(Image.Height)

                Image.SetPixel(x, y, Color.FromArgb(random.Next))
            Next

            '画图片的边框线
            g.DrawRectangle(New Pen(Color.Silver), 0, 0, Image.Width - 1, Image.Height - 1)

            Dim ms As IO.MemoryStream = New IO.MemoryStream
            Image.Save(ms, Drawing.Imaging.ImageFormat.Gif)
            Response.ClearContent()
            Response.ContentType = "image/Gif"
            Response.BinaryWrite(ms.ToArray)

        Finally

            g.Dispose()
            Image.Dispose()

        End Try
    End Function


End Class