' 导入命名空间
Imports System.Security.Permissions 
Imports System.Web
Imports System.Web.UI.WebControls 
Imports System.Web.UI.WebControls.WebParts

Namespace Samples.AspNet.VB.Controls

<AspNetHostingPermission(SecurityAction.Demand, _ 
  Level := AspNetHostingPermissionLevel.Minimal)> _ 
<AspNetHostingPermission(SecurityAction.InheritanceDemand, _
  Level := AspNetHostingPermissionLevel.Minimal)> _ 
Public Class TextDisplayWebPart 
  Inherits WebPart
  Private _contentText As String = Nothing
  Private input As TextBox
  Private DisplayContent As Label 
  Private Const _subTitle as String = "Contoso, Ltd"
  
  
  Public Sub New()  
    Me.AllowClose = False 
  End Sub 
  
  <Personalizable(), WebBrowsable()>  _ 
  Public Property ContentText() As String 
    Get 
      Return _contentText 
    End Get 
    Set 
      _contentText = value
    End Set 
  End Property
    
  Protected Overrides Sub CreateChildControls() 
    Controls.Clear()
    DisplayContent = New Label()
    DisplayContent.Text = Me.ContentText
    DisplayContent.BackColor = _
      System.Drawing.Color.LightBlue
    Me.Controls.Add(DisplayContent) 
    input = New TextBox() 
    Me.Controls.Add(input)
    Dim update As New Button()
    update.Text = "Set Label Content" 
    AddHandler update.Click, AddressOf Me.submit_Click
    Me.Controls.Add(update) 
    ChildControlsCreated = True 
  
  End Sub 
  
  Public Overrides ReadOnly Property Subtitle() As String
    Get
      Return _subTitle 
    End Get
  End Property

  Private Sub submit_Click(ByVal sender As Object, _
                           ByVal e As EventArgs)  
    ' Update the label string.
    If input.Text <> String.Empty Then
      _contentText = input.Text & "<br />"
      input.Text = String.Empty 
      DisplayContent.Text = Me.ContentText
    End If
  
  End Sub 
  
End Class 

End Namespace