如何通过进程得到窗体句柄？

这段代码你看下 希望对你有帮助 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
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
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 CloseHandle Lib "kernel32" (ByVal hObject As Long) As Long

'查找进程的函数
Private Function fun_FindProcess(ByVal ProcessName As String) As Long
Dim strdata As String
Dim my As PROCESSENTRY32
Dim l As Long
Dim l1 As Long
Dim mName As String
Dim i As Integer, pid As Long
l = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0)
If l Then
my.dwSize = 1060
If (Process32First(l, my)) Then
Do
i = InStr(1, my.szExeFile, Chr(0))
mName = LCase(Left(my.szExeFile, i - 1))
If mName = LCase(ProcessName) Then
pid = my.th32ProcessID
fun_FindProcess = pid
Exit Function
End If
Loop Until (Process32Next(l, my) < 1)
End If
l1 = CloseHandle(l)
End If
fun_FindProcess = 0
End Function

Private Sub Form_Load()
if fun_FindProcess("123.exe") <> 0 then
Text1.Text="123.exe程序已启动"
Else
Text1.Text = ""
End If
End Sub

http://blog.csdn.net/xykwgjyygy/archive/2008/03/12/2172900.aspx有你需要的，太多了，不解释和粘贴出来了，自己去看！！！