登录验证组件
Imports SystemSecurityCryptography
Imports SystemText
Imports SystemData
Imports SystemDataSqlClient
Public Class ValidatorClass Validator
Inherits SystemComponentModelComponent
Private username As String
Private userpwd As String
Public Property vUsername()Property vUsername() As String
Get
Return username
End Get
Set(ByVal Value As String)
username = Value
End Set
End Property
Public Property vUserpwd()Property vUserpwd() As String
Get
Return userpwd
End Get
Set(ByVal Value As String)
userpwd = Value
End Set
End Property
转换为ＭＤ５
Private Function convertMD()Function convertMD(ByVal pwd As String) As String
Dim md As New MDCryptoServiceProvider
Dim password As Byte() = (New ASCIIEncoding)GetBytes(pwd)
转换为哈希值Byte数组
Dim mdByte As Byte() = mdComputeHash(password)
Dim mdString As String = SystemBitConverterToString(mdByte)
Dim mdString As String = (New ASCIIEncoding)GetString(mdByte)
Return mdString
End Function
Public Function validate()Function validate() As Boolean
连接到Users表
Dim myConnection As New SqlConnection(server=localhost;database=TEST;Trusted_Connection=yes;user id=sa;password=;)
Dim selectAdapter As New SqlDataAdapter(select * from Users where UserName= + username + + and Password= + convertMD(userpwd) + myConnection)
Dim ds As New DataSet
Try
selectAdapterFill(ds Users)
If (dsTables()RowsCount > ) Then
Return True
Else
Return False
End If
Catch ep As SqlException
MsgBox(连接数据库出错)
Catch pp As Exception
MsgBox(Oh发生了不可预料的事情在你身边你死定了退出吧)
End Try
End Function
#Region 组件设计器生成的代码
Public Sub New()Sub New(ByVal Container As SystemComponentModelIContainer)
MyClassNew()
WindowsForms 类撰写设计器支持所必需的
ContainerAdd(Me)
End Sub
Public Sub New()Sub New()
MyBaseNew()
该调用是组件设计器所必需的
InitializeComponent()
在 InitializeComponent() 调用之后添加任何初始化
End Sub
组件重写 dispose 以清理组件列表
Protected Overloads Overrides Sub Dispose()Sub Dispose(ByVal disposing As Boolean)
If disposing Then
If Not (components Is Nothing) Then
componentsDispose()
End If
End If
MyBaseDispose(disposing)
End Sub
组件设计器所必需的
Private components As SystemComponentModelIContainer
注意: 以下过程是组件设计器所必需的
可以使用组件设计器修改此过程
不要使用代码编辑器修改它
<SystemDiagnosticsDebuggerStepThrough()> Private Sub InitializeComponent()Sub InitializeComponent()
components = New SystemComponentModelContainer
End Sub
#End Region
End Class
简介组件其实是一段可以重用的代码通过遵循IComponent接口的标准来实现一个组件所以有组件都是派生于Component类由Component类来实现IComponent接口在组件中应正确使用函数的访问级别来控制外部对其的访问限制
只要有足够的权限就可以将组件放到自己的程序中而不用担心组件会产生多大的错误因为组件已经经过测试的比如说可以把一段登录的程序做成一个组件或者把经常使用到的一些功能也做成组件这样就可以减少开发中的错误也可以缩短开发时间组件之间也可以互相套用如一个组件引用另一个组件都是没问题但要先在Add Reference中添加对组件的引用在NET中是通过把组件放在程序集中来实现的程序集中存放着这些组件所依赖的文件信息和所在路径因此CLR就可以通过这些信息来确定组件所需要的其他程序集的位置
（ 另外在组件设计过程中应好好利用接口来设计组件）
在VS中创建组件选建一个Project再从模板中选Class LibraryOK接着再从Project菜单中Add Component到些为止组件的一个框架就呈现在眼前平台自动继承了Component类和构造函数可以删除原先创建类库时自动生成的Class看应用的需要接着就可以在组件类里写要实现的功能最后从Build（生成）菜单中选择Build Solution(生成解决方案）来生成组件如果生成成功的话到应用程序的BIN目录下会看到一个DLL文件
引用组件只要在Solution Explorer窗口中添加对DLL的Reference就可以了
Imports loginValidator
Imports SystemData
Imports SystemDataSqlClient
Public Class loginFormClass loginForm
Inherits SystemWindowsFormsForm
#Region Windows 窗体设计器生成的代码
Public Sub New()Sub New()
MyBaseNew()
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()Sub Dispose(ByVal disposing As Boolean)
If disposing Then
If Not (components Is Nothing) Then
componentsDispose()
End If
End If
MyBaseDispose(disposing)
End Sub
Windows 窗体设计器所必需的
Private components As SystemComponentModelIContainer
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 lblUserPwd As SystemWindowsFormsLabel
Friend WithEvents lblUserName As SystemWindowsFormsLabel
Friend WithEvents txtUserName As SystemWindowsFormsTextBox
Friend WithEvents txtUserPwd As SystemWindowsFormsTextBox
Friend WithEvents btnSubmit As SystemWindowsFormsButton
Friend WithEvents btnExit As SystemWindowsFormsButton
Friend WithEvents Label As SystemWindowsFormsLabel
Friend WithEvents Label As SystemWindowsFormsLabel
Friend WithEvents btnCancel As SystemWindowsFormsButton
Friend WithEvents Label As SystemWindowsFormsLabel
<SystemDiagnosticsDebuggerStepThrough()> Private Sub InitializeComponent()Sub InitializeComponent()
Dim resources As SystemResourcesResourceManager = New SystemResourcesResourceManager(GetType(loginForm))
MelblUserPwd = New SystemWindowsFormsLabel
MelblUserName = New SystemWindowsFormsLabel
MetxtUserName = New SystemWindowsFormsTextBox
MetxtUserPwd = New SystemWindowsFormsTextBox
MebtnSubmit = New SystemWindowsFormsButton
MebtnExit = New SystemWindowsFormsButton
