form1.vb

Visual.Basic.NET实用编程百例-47.6M.zip

Public Class Form1
    Inherits System.Windows.Forms.Form

#Region " Windows 窗体设计器生成的代码 "

    Public Sub New()
        MyBase.New()

        '该调用是 Windows 窗体设计器所必需的。
        InitializeComponent()

        '在 InitializeComponent() 调用之后添加任何初始化

    End Sub

    '窗体重写 dispose 以清理组件列表。
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Windows 窗体设计器所必需的
    Private components As System.ComponentModel.IContainer

    '注意: 以下过程是 Windows 窗体设计器所必需的
    '可以使用 Windows 窗体设计器修改此过程。
    '不要使用代码编辑器修改它。
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
    Friend WithEvents Button1 As System.Windows.Forms.Button
    Friend WithEvents Label1 As System.Windows.Forms.Label
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.TextBox1 = New System.Windows.Forms.TextBox
        Me.Button1 = New System.Windows.Forms.Button
        Me.Label1 = New System.Windows.Forms.Label
        Me.SuspendLayout()
        '
        'TextBox1
        '
        Me.TextBox1.Location = New System.Drawing.Point(112, 24)
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.Size = New System.Drawing.Size(160, 21)
        Me.TextBox1.TabIndex = 0
        Me.TextBox1.Text = ""
        '
        'Button1
        '
        Me.Button1.Location = New System.Drawing.Point(104, 72)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New System.Drawing.Size(100, 30)
        Me.Button1.TabIndex = 1
        Me.Button1.Text = "验证"
        '
        'Label1
        '
        Me.Label1.Location = New System.Drawing.Point(8, 24)
        Me.Label1.Name = "Label1"
        Me.Label1.TabIndex = 2
        Me.Label1.Text = "请输入IP地址："
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)
        Me.ClientSize = New System.Drawing.Size(296, 125)
        Me.Controls.Add(Me.Label1)
        Me.Controls.Add(Me.Button1)
        Me.Controls.Add(Me.TextBox1)
        Me.Name = "Form1"
        Me.Text = "验证IP地址的正确性"
        Me.ResumeLayout(False)

    End Sub

#End Region

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        If Len(TextBox1.Text) = 0 Then
            MsgBox("请输入需要验证的IP地址", , "IP 验证器")
        Else
            Valid_IP(TextBox1.Text)  '调用函数
        End If
    End Sub

    Public Function Valid_IP(ByVal IP As String) As Boolean
        Dim i As Integer
        Dim dot_count As Integer
        Dim test_octet As String
        Dim byte_check
        IP = Trim$(IP)
        If Len(IP) < 8 Then  '判断长度
            Valid_IP = False
            MsgBox(IP & " 是无效的", , "IP 验证器")  '显示信息
            Exit Function
        End If
        i = 1
        dot_count = 0
        For i = 1 To Len(IP)
            If Mid$(IP, i, 1) = "." Then
                dot_count = dot_count + 1
                test_octet = ""
                If i = Len(IP) Then
                    Valid_IP = False
                    MsgBox(IP & " 是无效的", , "IP 验证器")
                    Exit Function
                End If
            Else
                test_octet = test_octet & Mid$(IP, i, 1)
                On Error Resume Next
                byte_check = CByte(test_octet)
            End If
        Next i
        If dot_count <> 3 Then
            Valid_IP = False
            Exit Function
        End If
        Valid_IP = True
        MsgBox(IP & " 是有效的", , "IP 验证器")
    End Function

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    End Sub
End Class