setforegroundwindow只能激活桌面级的父窗体，即使后面跟的hwnd是子窗体的hwnd也不行！

激活子窗体，可以先用setforegroundwindow把父窗体带到前台，然后用以下消息激活子窗体：

 'Private Const WM_MOUSEACTIVATE=&H21

SendMessage thwnd, WM_MOUSEACTIVATE, 0, 0  

'Private Const WM_LBUTTONDOWN = &H201

SendMessage tHwnd, WM_LBUTTONDOWN, 0, 0 

或者直接用SendMessage thwnd, 33, 0, 0来激活子窗体。

在form1下面新建3个command按钮，然后打开excel，新建book1,book2，把焦点切换到book1,然后测试以下代码，会把焦点切换到book2：

'form1的代码：

Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Long

Private Declare Function FindWindowEx Lib "user32" Alias "FindWindowExA" (ByVal hWnd1 As Long, ByVal hWnd2 As Long, ByVal lpsz1 As String, ByVal lpsz2 As String) As Long

Private Declare Function SetForegroundWindow Lib "user32" (ByVal hwnd As Long) As Long

Private Declare Function PostMessage Lib "user32" Alias "PostMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam 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 Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)

Private Const WM_MOUSEACTIVATE = &H21

Private Const WM_LBUTTONDOWN = &H201

Private Sub Command1_Click()

' Call SetNumLock(False) '关闭NumLock键

' CALL MySendKey (vbKeyCapital)

' MsgBox GetAsyncKeyState(vbKeyCapital)

If GetKeyState(vbKeyCapital) = 1 Then '如果CAPSLOCK被按下

SendKeys "{CAPSLOCK}", False

' Call MySendKey(vbKeyCapital)

' ScanCode = MapVirtualKey(vbKeyCapital, 0)

' Call keybd_event(vbKeyCapital, ScanCode, 0, 0)

' Sleep 1000

' Call keybd_event(vbKeyCapital, ScanCode, KEYEVENTF_KEYUP, 0)

' Sleep 1000

End If

Dim dHwnd As Long

Dim tHwnd As Long

dHwnd = FindWindow("XLMAIN", vbNullString)

If dHwnd > 0 Then

tHwnd = FindWindowEx(dHwnd, ByVal 0&, "XLDESK", vbNullString)

If tHwnd > 0 Then

tHwnd = FindWindowEx(tHwnd, ByVal 0&, vbNullString, "Book2")

End If

End If

If tHwnd = 0 Then

MsgBox "请先新建两个空白excel，名字叫做book1,book2"

Exit Sub

End If

SetForegroundWindow dHwnd '激活父窗体

Sleep 1000 '等待窗口切换

'Private Const WM_MOUSEACTIVATE = &H21

' SendMessage tHwnd, WM_MOUSEACTIVATE, 0, 0

' Private Const WM_LBUTTONDOWN = &H201

SendMessage tHwnd, WM_LBUTTONDOWN, 0, 0

' Private Const WM_PARENTNOTIFY = &H210

' Private Const WM_ACTIVATE = &H6

' SendMessage hwnd4, WM_ACTIVATE, 0, 0

' Private Const WM_LBUTTONDOWN = &H201

' SendMessage hwnd4, WM_LBUTTONDOWN, 0, 0

Sleep 1000 '等待窗口切换

' SendKeys "{CAPSLOCK}", FALSE

Sleep 1000

SendKeys "{enter}"

SendKeys "AAA", False

SendKeys "bbb", False

SendKeys "CCC", False

SendKeys "ddd", False

SendKeys "EEE", False

End Sub

Private Sub Command2_Click()

End

End Sub

Private Sub Command3_Click()

dHwnd = FindWindow("Notepad", vbNullString)

If dHwnd > 0 Then

tHwnd = FindWindowEx(dHwnd, ByVal 0&, "Edit", vbNullString)

End If

SetForegroundWindow dHwnd '激活父窗体

MySendKey vbKeyA

End Sub