- 首先是網頁版的網絡應用程式不一定需要在用戶電腦上安裝，(註: 因應功能而定)。
- 你可以在其他非windows的系統上使用網頁版的網絡應用程式，檢視和管理網絡資源。
- 可以把已寫好的網絡應用程式碼複製到VB.NET，並修改成桌面應用程式使用。
這次範例只需修改的Default.aspx，首先新增一個專案名為NetServerEnum，並選擇 ASP.NET web application，然後出現了Default.aspx可以作修改。
以下是相關修改的程式碼:
Default.aspx :1: <%@ Page Language="vb" AutoEventWireup="false" CodeBehind="Default.aspx.vb" Inherits="NetServerEnum._Default" %>
2: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
3: <html xmlns="http://www.w3.org/1999/xhtml">
4: <head id="Head1" runat="server">
5: <title></title>
6: </head>
7: <body>
8:
9: <form id="form1" runat="server">
10: Network Devices :<br />
11: <br />
12: <asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
13: <br />
14: <asp:ListBox ID="ListBox1" runat="server" Height="193px" Width="249px">
15: </asp:ListBox>
16: </form>
17:
18: </body>
19: </html>
Default.aspx.vb
1: Default.aspx.vb
2:
3: Imports System.Runtime.InteropServices
4:
5: Partial Public Class _Default
6: Inherits System.Web.UI.Page
7:
8: #Region "API Declares"
9: Private Const SV_TYPE_WORKSTATION As Integer = &H1
10: Private Const SV_TYPE_SERVER As Integer = &H2 ' All Servers
11: Private Const SV_TYPE_SQLSERVER As Integer = &H4 ' SQL Server
12: Private Const SV_TYPE_DOMAIN_CTRL As Integer = &H8
13: Private Const SV_TYPE_DOMAIN_BAKCTRL As Integer = &H10
14: Private Const SV_TYPE_TIME_SOURCE As Integer = &H20
15: Private Const SV_TYPE_SERVER_UNIX As Integer = SV_TYPE_XENIX_SERVER
16: Private Const SV_TYPE_NT As Integer = &H1000
17: Private Const SV_TYPE_WFW As Integer = &H2000
18: Private Const SV_TYPE_POTENTIAL_BROWSER As Integer = &H10000
19: Private Const SV_TYPE_BACKUP_BROWSER As Integer = &H20000
20: Private Const SV_TYPE_MASTER_BROWSER As Integer = &H40000
21: Private Const SV_TYPE_DOMAIN_MASTER As Integer = &H80000
22: Private Const SV_TYPE_SERVER_OSF As Integer = &H100000
23: Private Const SV_TYPE_SERVER_VMS As Integer = &H200000
24: Private Const SV_TYPE_WINDOWS As Integer = &H400000 '/* Windows95 and above */
25: Private Const SV_TYPE_DFS As Integer = &H800000 '/* Root of a DFS tree */
26: Private Const SV_TYPE_CLUSTER_NT As Integer = &H1000000 '/* NT Cluster */
27: Private Const SV_TYPE_DCE As Integer = &H10000000 'RESOURCE ENUMERATION.
28: Private Const SV_TYPE_SERVER_MFPN As Integer = &H4000
29: Private Const SV_TYPE_SERVER_NT As Integer = &H8000
30: Private Const SV_TYPE_AFP As Integer = &H40
31: Private Const SV_TYPE_NOVELL As Integer = &H80
32: Private Const SV_TYPE_DOMAIN_MEMBER As Integer = &H100
33: Private Const SV_TYPE_PRINTQ_SERVER As Integer = &H200
34: Private Const SV_TYPE_DIALIN_SERVER As Integer = &H400
35: Private Const SV_TYPE_XENIX_SERVER As Integer = &H800
36: Private Const SV_TYPE_ALL As Integer = &HFFFFFFFF
37: Private Const NERR_SUCCESS As Integer = 0&
38: Private Const ERROR_ACCESS_DENIED As Integer = 5&
39:
40: Structure Server_info_101
41: Public Platform_ID As Integer
42: Public Name As String
43: Public Version_Major As Integer Public Version_Minor As Integer
44: Public Type As Integer
45: Public Comment As String
46: End Structure
47:
48: Declare Function NetApiBufferFree Lib "Netapi32.dll" _
49: (ByVal lpBuffer As Integer) As Integer
50:
51: Private machine As Server_info_101
52: Private getResult As String
53:
54: Declare Unicode Function NetServerEnum Lib "Netapi32.dll" _
55: (ByVal Servername As Integer, ByVal level As Integer, _
56: ByRef buffer As Integer, ByVal PrefMaxLen As Integer, _
57: ByRef EntriesRead As Integer, ByRef TotalEntries As Integer, _
58: ByVal ServerType As Integer, ByVal DomainName As String, _
59: ByRef ResumeHandle As Integer) As Integer
60:
61: Declare Unicode Function NetGetJoinInformation Lib "Netapi32.dll" ( _
62: ByVal lpServer As Integer, _
63: ByRef lpNameBuffer As Integer, _
64: ByRef BufferType As Integer) As Integer
65:
66: #End Region
67:
68: #Region "Get network device"
69:
70: Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load, Me.Load
71:
72: Dim model As New ArrayList
73: Dim networkName As String = GetJoinState()
74:
75: If networkName <> "" Then
76: model = GetServerList(networkName)
77: End If
78:
79: If model.Count > 0 Then
80: For Each i In model
81: ListBox1.Items.Add(i.ToString)
82: Next
83: End If
84:
85: End Sub
86:
87: Private Function GetServerList(ByVal dnName As String) As ArrayList
88:
89: Dim i, Result, EntriesRead, TotalEntries, ResumeHandle As Integer
90: Dim MaxLenPref As Integer = -1
91: Dim level As Integer = 101
92: Dim BufPtr As Integer
93:
94: Result = NetServerEnum(0, level, BufPtr, MaxLenPref, EntriesRead, TotalEntries, _SV_TYPE_ALL, dnName, ResumeHandle)
95:
96: Dim PCList As New ArrayList
97:
98: If Result = 0 Then
99: For i = 0 To EntriesRead - 1
100: Dim ptr As IntPtr = New IntPtr(BufPtr)
101: machine = CType(Marshal.PtrToStructure(ptr, GetType(Server_info_101)), _Server_info_101)
102: BufPtr = BufPtr + Len(machine)
103: PCList.Add(machine.Name)
104: Next
105: End If
106:
107: NetApiBufferFree(BufPtr)
108: Return PCList
109:
110: End Function
111:
112: Private Function GetJoinState() As String
113:
114: Dim bufptr, dwBufferType, returnJoinState As Integer
115: Dim Networkmode As String = ""
116: Dim modename As String = ""
117:
118: returnJoinState = NetGetJoinInformation(0, _
119: bufptr, _
120: dwBufferType)
121:
122: If returnJoinState = NERR_SUCCESS Then
123:
124: Select Case dwBufferType
125: Case 0 : Networkmode = "未知"
126: Case 1 : Networkmode = "單一"
127: Case 2 : Networkmode = "工作群組"
128: Case 3 : Networkmode = "網域"
129: Case Else : Networkmode = "網域模式超出正常類別"
130: End Select
131:
132: Dim ptr As New IntPtr(bufptr)
133: modename = Marshal.PtrToStringAuto(ptr)
134: If modename <> "" Or Networkmode <> "" Then
135: Label1.Text = Networkmode + " : " + modename
136: End If
137:
138: End If
139:
140: NetApiBufferFree(bufptr)
141: Return modename
142:
143: End Function
144:
145: #End Region
146:
147: End Class
而以上的範例中，會使用到幾個 Win32 API 函式，它們分別是NetGetJoinInformation，NetServerEnum和NetApiBufferFree。而這些Win32 API 函式都是一些 Unmanaged 程式碼(在執行階段以外執行的程式碼)。但我們的程式都是一些 Managed 程式碼(在執行階段控制之下執行的程式碼)，所以為了能夠令這些 Unmanaged 程式碼與 Managed 程式碼互動，需要藉著控制封送處理(Marshaling)，設定 Unmanaged 程式碼與 Managed 程式碼兩者之間的互動參數成合適的結構才可與互通。
因此，我在以上的程式碼包括匯入了System.Runtime.InteropServices的命名空間，此命名空間就是負責控制封送處理 (Marshaling) 行為，定義 Unmanaged 程式碼與Managed程式碼之間的互動參數之結構或字串表示的方式。
另外，先前提及的幾個 Win32 API 函式的功能如下:
NetGetJoinInformation - 查詢目前的網域模式和網域名稱，傳回值是0表示查詢成功。
NetServerEnum - 查詢前的網域中的機器資料包括機器名稱、機器平台版本和提示等，但必須提供網域名稱才能查詢，傳回值是0表示查詢成功。
NetApiBufferFree - 清除查詢網域時的暫存資料。
本範例不太複雜，提供源碼下載參考 :
https://docs.google.com/open?id=0BxRiNrIXEFArSmdzTm5vVnhTOG1YMk1qTzF4MDNIQQ
請下載後以Mircosoft Visual Web developer Express 2008 開啟
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