网络编程

[rocketliu8899]

请问各位大虾:

1. 我如何能得到LAN中的一台主机的网络卡的MAC地址,IP地址,用户名称,机器名称


,当LAN中有一台主机更改了IP地址时,我能探测的到.

2.向"金山词霸"的屏幕取词是如何实现的.

3.我的软件给用户一个使用期限,可以用注册表来限制,但不安全,听说可以用DLL来控制,不知道该如何实现

先谢谢各位大虾

[3661512]

一个取词的例子
一个richtextbox，两个label
代码如下：

Option Explicit
Private Const EM_CHARFROMPOS& = &HD7
Private Type POINTAPI
X As Long
Y As Long
End Type
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVa
l hWnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As
Long
' Return the word the mouse is over.
Public Function RichWordOver(rtf As RichTextBox, X As Single, Y As Single) A
s String
Dim pt As POINTAPI
Dim pos As Integer
Dim start_pos As Integer
Dim end_pos As Integer
Dim ch As String
Dim txt As String
Dim txtlen As Integer
' 把位置坐标转换为像素.
pt.X = X \ Screen.TwipsPerPixelX
pt.Y = Y \ Screen.TwipsPerPixelY
' Get the character number
pos = SendMessage(rtf.hWnd, EM_CHARFROMPOS, 0&, pt)
If pos <= 0 Then Exit Function
'查找单词的开始位置.
txt = rtf.Text
For start_pos = pos To 1 Step -1
ch = Mid$(rtf.Text, start_pos, 1)
' 允许数字,字母,下划线
If Not ( _
(ch >= "0" And ch <= "9") Or _
(ch >= "a" And ch <= "z") Or _
(ch >= "A" And ch <= "Z") Or _
ch = "_" _
) Then Exit For
Next start_pos
start_pos = start_pos + 1
'查找单词的结尾
txtlen = Len(txt)
For end_pos = pos To txtlen
ch = Mid$(txt, end_pos, 1)
' 允许数字,字母,下划线
If Not ( _
(ch >= "0" And ch <= "9") Or _
(ch >= "a" And ch <= "z") Or _
(ch >= "A" And ch <= "Z") Or _
ch = "_" _
) Then Exit For
Next end_pos
end_pos = end_pos - 1
If start_pos <= end_pos Then _
RichWordOver = Mid$(txt, start_pos, end_pos - start_pos + 1)
End Function
Private Sub Form_Load()
rtfTest.Text = "Welcome to use source code provided by Alp Studio" & _
vbCrLf & vbCrLf & "This example program is provided as is with no wa
rranty of any kind" & _
vbCrLf & vbCrLf & "Send the control the EM_CHARFROMPOS message to ma
ke it return the character closest to the mouse position." & _
vbCrLf & vbCrLf & "http://dropwater.163.net"
End Sub
Private Sub rtftest_MouseMove(Button As Integer, Shift As Integer, X As Sing
le, Y As Single)
Dim txt As String
txt = RichWordOver(rtfTest, X, Y)
If lblCurrentWord.Caption <> txt Then _
lblCurrentWord.Caption = txt
End Sub

鼠标屏幕取词技术的原理和实现
http://ttcode.51.net/jishu/delphi/delphi%20(29).htm

[3661512]

3.我的软件给用户一个使用期限,可以用注册表来限制,但不安全,听说可以用DLL来控制,不知道该如何实现

DLL和EXE文件之间互相检查对方的完成性,如果不完整,程序就无法运行.

1. 我如何能得到LAN中的一台主机的网络卡的MAC地址,IP地址,用户名称,机器名称

,当LAN中有一台主机更改了IP地址时,我能探测的到.

WIN2000自带的命令行就可以办到了

[rocketliu8899]

谢谢你, 3661512

1.对于问题3,能详细一点吗,最好有一个例子,

2.问题1,我知道WIN2000有自带的命令NBTSTAT,但如果是自己写,该如何写呢?