@Amelie ：

  Ret1 = FindWindow（vbNullString，VBAProject  -  Project Properties）

如果Ret1  ChildRet1 = FindWindowEx（Ret1，ByVal 0&Button，vbNullString）

如果ChildRet1& 0然后
 strBuff = String（GetWindowTextLength（ChildRet1）+ 1，Chr $（0））

 GetWindowText ChildRet1，strBuff，Len（strBuff）

 ButCap = strBuff 

 Do While ChildRet1<> 0 
如果InStr（1，ButCap，OK）然后
 OpenRet1 = ChildRet1 
退出Do 
如果

 ChildRet1 = FindWindowEx（Ret， ChildRet1Button，vbNullString）
 strBuff = String（GetWindowTextLength（ChildRet1）+ 1，Chr $（0））
 GetWindowText ChildRet1，strBuff，Len（strBuff）
 ButCap = strBuff 
 Loop 

如果OpenRet1<> 0 Then SendMessageA OpenRet1，BM_CLICK，0，vbNullString 
 End If 
 End If 
 

I am trying to unlock a password protected excel sheet using code found here

I am successfully able to unlock the excel file, but I do not want the user to see any windows. I tried setting this setting: xlAp.Visible = False But I still see the Project Properties window. How can you hide all the windows in this process?

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 GetWindowText Lib "user32" Alias "GetWindowTextA" _
(ByVal hwnd As Long, ByVal lpString As String, ByVal cch As Long) As Long

Private Declare Function GetWindowTextLength Lib "user32" Alias _
"GetWindowTextLengthA" (ByVal hwnd 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

Dim Ret As Long, ChildRet As Long, OpenRet As Long
Dim strBuff As String, ButCap As String
Dim MyPassword As String

Const WM_SETTEXT = &HC
Const BM_CLICK = &HF5

Sub UnlockVBA()
    Dim xlAp As Object, oWb As Object

    Set xlAp = CreateObject("Excel.Application")

    xlAp.Visible = True

    '~~> Open the workbook in a separate instance
    Set oWb = xlAp.Workbooks.Open("C:\Sample.xlsm")

    '~~> Launch the VBA Project Password window
    '~~> I am assuming that it is protected. If not then
    '~~> put a check here.
    xlAp.VBE.CommandBars(1).FindControl(ID:=2578, recursive:=True).Execute

    '~~> Your passwword to open then VBA Project
    MyPassword = "Blah Blah"

    '~~> Get the handle of the "VBAProject Password" Window
    Ret = FindWindow(vbNullString, "VBAProject Password")

    If Ret <> 0 Then
        'MsgBox "VBAProject Password Window Found"

        '~~> Get the handle of the TextBox Window where we need to type the password
        ChildRet = FindWindowEx(Ret, ByVal 0&, "Edit", vbNullString)

        If ChildRet <> 0 Then
            'MsgBox "TextBox's Window Found"
            '~~> This is where we send the password to the Text Window
            SendMess MyPassword, ChildRet

            DoEvents

            '~~> Get the handle of the Button's "Window"
            ChildRet = FindWindowEx(Ret, ByVal 0&, "Button", vbNullString)

            '~~> Check if we found it or not
            If ChildRet <> 0 Then
                'MsgBox "Button's Window Found"

                '~~> Get the caption of the child window
                strBuff = String(GetWindowTextLength(ChildRet) + 1, Chr$(0))
                GetWindowText ChildRet, strBuff, Len(strBuff)
                ButCap = strBuff

                '~~> Loop through all child windows
                Do While ChildRet <> 0
                    '~~> Check if the caption has the word "OK"
                    If InStr(1, ButCap, "OK") Then
                        '~~> If this is the button we are looking for then exit
                        OpenRet = ChildRet
                        Exit Do
                    End If

                    '~~> Get the handle of the next child window
                    ChildRet = FindWindowEx(Ret, ChildRet, "Button", vbNullString)
                    '~~> Get the caption of the child window
                    strBuff = String(GetWindowTextLength(ChildRet) + 1, Chr$(0))
                    GetWindowText ChildRet, strBuff, Len(strBuff)
                    ButCap = strBuff
                Loop

                '~~> Check if we found it or not
                If OpenRet <> 0 Then
                    '~~> Click the OK Button
                    SendMessage ChildRet, BM_CLICK, 0, vbNullString
                Else
                    MsgBox "The Handle of OK Button was not found"
                End If
            Else
                 MsgBox "Button's Window Not Found"
            End If
        Else
            MsgBox "The Edit Box was not found"
        End If
    Else
        MsgBox "VBAProject Password Window was not Found"
    End If
End Sub

Sub SendMess(Message As String, hwnd As Long)
    Call SendMessage(hwnd, WM_SETTEXT, False, ByVal Message)
End Sub

@Amelie:

    Ret1 = FindWindow(vbNullString, "VBAProject - Project Properties")

If Ret1 <> 0 Then
ChildRet1 = FindWindowEx(Ret1, ByVal 0&, "Button", vbNullString)

If ChildRet1 <> 0 Then
    strBuff = String(GetWindowTextLength(ChildRet1) + 1, Chr$(0))

    GetWindowText ChildRet1, strBuff, Len(strBuff)

    ButCap = strBuff

    Do While ChildRet1 <> 0
        If InStr(1, ButCap, "OK") Then
            OpenRet1 = ChildRet1
            Exit Do
        End If

        ChildRet1 = FindWindowEx(Ret, ChildRet1, "Button", vbNullString)
        strBuff = String(GetWindowTextLength(ChildRet1) + 1, Chr$(0))
        GetWindowText ChildRet1, strBuff, Len(strBuff)
        ButCap = strBuff
    Loop

    If OpenRet1 <> 0 Then SendMessageA OpenRet1, BM_CLICK, 0, vbNullString
End If
End If