獲得系統中運行的程序及運用的DLL文件

     在Microsoft Visual Studio中提供了一個可以查看當前運行的程序的工具Process Viewer
可以查看系統中當前運行的程序，下面我來介紹在你的程序中如何實現這種功能。
    Windows提供了一系列的API函數可以建立當前的程序、模塊、線程的“快照”(SnapShot)
利用這些“快照”函數就可以獲得當前的程序、模塊等的信息。
    下面實現的步驟：

    1、在Form1中加入一個CommandButton控件、兩個ListBox控件
    2、在Form1中加入如下代碼：

Private Declare Function CreateToolhelp32Snapshot Lib "kernel32" _
        (ByVal dwFlags As Long, ByVal th32ProcessID As Long) As Long
Private Declare Function Process32First Lib "kernel32" _
        (ByVal hSnapshot As Long, lppe As PROCESSENTRY32) As Long
Private Declare Function Process32Next Lib "kernel32" _
        (ByVal hSnapshot As Long, lppe As PROCESSENTRY32) As Long
Private Declare Function Module32First Lib "kernel32" _
        (ByVal hSnapshot As Long, lppe As MODULEENTRY32) As Long
Private Declare Function Module32Next Lib "kernel32" _
        (ByVal hSnapshot As Long, lppe As MODULEENTRY32) As Long

Private Declare Function CloseHandle Lib "kernel32" (ByVal _
        hObject As Long) As Long
Private Declare Function SendMessage Lib "user32" Alias _
        "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As _
        Long, ByVal wParam As Long, lParam As Any) As Long

Private Type PROCESSENTRY32
    dwSize As Long
    cntUsage As Long
    th32ProcessID As Long
    th32DefaultHeapID As Long
    th32ModuleID As Long
    cntThreads As Long
    th32ParentProcessID As Long
    pcPriClassBase As Long
    dwFlags As Long
    szExeFile As String * 1024
End Type

Private Type MODULEENTRY32
    dwSize As Long
    th32ModuleID As Long
    th32ProcessID As Long
    GlblcntUsage As Long
    ProccntUsage As Long
    modBaseAddr As Byte
    modBaseSize As Long
    hModule As Long
    szModule As String * 256
    szExePath As String * 1024
End Type

Const LB_SETHORIZONTALEXTENT = &H194
Const TH32CS_SNAPHEAPLIST = &H1
Const TH32CS_SNAPPROCESS = &H2
Const TH32CS_SNAPTHREAD = &H4
Const TH32CS_SNAPMODULE = &H8
Const TH32CS_SNAPALL = (TH32CS_SNAPHEAPLIST Or TH32CS_SNAPPROCESS _
                        Or TH32CS_SNAPTHREAD Or TH32CS_SNAPMODULE)
Const TH32CS_INHERIT = &H80000000

Dim MyEntry(100) As PROCESSENTRY32

Private Sub Command1_Click()
    Dim my As PROCESSENTRY32
    Dim l As Long
   
    List1.Clear
    l = SendMessage(List1.hwnd, &H194, 640, 0)
    '建立當前程序快照
    l = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0)
    If l Then
        my.dwSize = 1060
        If (Process32First(l, my)) Then '遍歷第一個程序
            '遍歷所有程序直到返回值為False
            Do
                List1.AddItem (Trim$(my.szExeFile))
                MyEntry(List1.ListCount - 1) = my
            Loop Until (Process32Next(l, my) < 1)
End If
'關閉快照句柄
CloseHandle l
End If
End Sub

Private Sub Form_Load()
Command1_Click
End Sub

Private Sub List1_Click()
Dim l As Long
Dim mm As MODULEENTRY32
Dim lm As Long
Dim astr As String

If MyEntry(List1.ListIndex).th32ProcessID <> 0 Then
        l = SendMessage(List2.hwnd, &H194, 640, 0)
        List2.Clear
         
        '根據程序快照句柄建立程序的模塊句柄
        lm = CreateToolhelp32Snapshot(TH32CS_SNAPMODULE, _
            MyEntry(List1.ListIndex).th32ProcessID)
        If lm > 0 Then
            mm.dwSize = Len(mm)
            '獲得第一個模塊
            If Module32First(lm, mm) Then
                '遍歷所有模塊知道返回值為False
                Do
                    If MyEntry(List1.ListIndex).th32ProcessID = _
                        mm.th32ProcessID Then
                         
                        astr = Left$(mm.szModule, (InStr(1, _
                            mm.szModule, Chr(0)) - 1))
                         
                        List2.AddItem astr
                    End If
                Loop Until (Module32Next(lm, mm) < 1)
End If
CloseHandle (lm)
End If
End If
End Sub

運行程序，List1中就列出當前運行的所有的程序的名稱及路徑，點擊其中任一個列表，
在List2中就會列出這個程序所使用的DLL的文件名。按下Command1重新獲得系統中運行的程序。
上面只是通過簡單的程序介紹了“快照”的建立和使用，只要稍加改造，就可以獲得諸如
程序的線程數、模塊尺寸、模塊在內存的基地址等信息。
以上程序在Windows95、VB5.0下運行通過。