有些软件如果你不输入正确的注册吗，那该死的“下一步”按钮就一直disable。这个disable按钮使用WindowFromPoint, FindWindowEx均无法得到.
不过，使用EnumChildWindows，GetWindow去可以枚举到每一个窗口中的所有控件，包括disabled的控件，找到了句柄，我们就可以操作了
测试环境：WINXP+VB6
具体的API函数请参考MSDN.
新建工程，在form中任意添加两个按钮，两个文本框。其中按钮2的Enabled属性为false
form的Caption设为” 激活程序的disabled的按钮”.
编译后，运行。
1． 我们先看看使用GetWindow枚举句柄的
我们先用FindWindow找到form窗口，然后找到窗口中所有的子控件句柄，然后使用EnableWindow函数激活
添加1个按钮，2个list控件。
Option Explicit
Private Declare Function FindWindow Lib "user32.dll" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Long
Private Declare Function GetClassName Lib "user32" Alias "GetClassNameA" (ByVal hwnd As Long, ByVal lpClassName As String, ByVal nMaxCount As Long) As Long
Private Declare Function EnableWindow Lib "user32.dll" (ByVal hwnd As Long, ByVal fEnable As Long) As Long
Private Declare Function GetWindow Lib "user32" (ByVal hwnd As Long, ByVal wCmd As Long) As Long
Const GW_CHILD = 5
Const GW_HWNDNEXT = 2
Const WM_GETTEXT = &HD
Const WM_ENABLE As Long = &HA
Private Sub Command2_Click()
Dim tWnd As Long
Dim bWnd As Long
Dim lpClassName As String
Dim RetVal As Long
Dim i As Integer
Dim mName As String
tWnd = FindWindow(vbNullString, "激活程序的disabled的按钮")
bWnd = GetWindow(tWnd, GW_CHILD)
Do While bWnd <> 0
lpClassName = Space(256)
‘这里得到类名主要是为了可以看出bWnd所对应的控件
RetVal = GetClassName(bWnd, lpClassName, 256)
i = InStr(1, lpClassName, Chr(0))
mName = Left(lpClassName, i - 1)
List1.AddItem bWnd & " " & mName
;list2主要是为了方便操作
List2.AddItem bWnd
‘继续寻找下一个控件
bWnd = GetWindow(bWnd, GW_HWNDNEXT)
Loop
End Sub
‘单击要激活的句柄
Private Sub List2_Click()
EnableWindow List2.List(List2.ListIndex), True
End Sub
好了，运行后，点击按钮，窗口中所有的控件句柄填充到列表框中，然后点击列表框，可以发现disabled的按钮被激活，可以运行了
2． 使用EnumChildWindows来枚举
函数功能：为指定的父窗口枚举子窗口
Private Declare Function EnumChildWindows Lib "user32" Alias "EnumChildWindows" (ByVal hWndParent As Long, ByVal lpEnumFunc As Long, ByVal lParam As Long) As Long
【参数表】
hWndParent ----- Long，欲枚举子窗口的父窗口的句柄
lpEnumFunc ----- Long，为每个子窗口调用的函数的指针。用AddressOf运算符获得函数在一个标准模块中的地址
代码如下：
窗口
Private Declare Function FindWindow Lib "user32.dll" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Long
Private Declare Function EnableWindow Lib "user32.dll" (ByVal hwnd As Long, ByVal fEnable As Long) As Long
Private Declare Function EnumChildWindows Lib "user32" (ByVal hWndParent As Long, ByVal lpEnumFunc As Long, ByVal lParam As Long) As Long
Const WM_ENABLE As Long = &HA
Private Sub Command1_Click()
Dim twnd As Long
twnd = FindWindow(vbNullString, "激活程序的disabled的按钮")
EnumChildWindows twnd, AddressOf EnumChildProc, ByVal 0&
End Sub
Private Sub List1_Click()
EnableWindow List1.List(List1.ListIndex), True
End Sub
模块
Option Explicit
Public Function EnumChildProc(ByVal hwnd As Long, ByVal lParam As Long) As Long
Form1.List1.AddItem hwnd
'继续枚举
EnumChildProc = 1
End Function
好了，运行后，点击按钮，窗口中所有的控件句柄填充到列表框中，然后点击列表框，可以发现disabled的按钮被激活，可以运行了