Info

Figure 13.13

Use an input box as a secure password field.

Figure 13.13

Use an input box as a secure password field.

Private Declare Function CallNextHookEx Lib "user32" (ByVal hHook As Long, ByVal ncode As Long, ByVal wParam As Long, lParam As Any) As Long

Private Declare Function GetModuleHandle Lib "kernel32" _

Alias "GetModuleHandleA" (ByVal lpModuleName As String) As Long

Private Declare Function SetWindowsHookEx Lib "user32" _ Alias "SetWindowsHookExA" _ (ByVal idHook As Long, ByVal lpfn As Long, _ ByVal hmod As Long,ByVal dwThreadId As Long) As Long

Private Declare Function UnhookWindowsHookEx Lib "user32" _ (ByVal hHook As Long) As Long

Private Declare Function SendDlgltemMessage Lib "user32" _ Alias "SendDlgltemMessageA" _ (ByVal hDlg As Long, _

ByVal nIDDlgltem As Long, ByVal wMsg As Long, _ ByVal wParam As Long, ByVal lParam As Long) 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 GetCurrentThreadId _ Lib "kernel32" () As Long

'Constants to be used in our API functions Private Const EM_SETPASSWORDCHAR = &HCC Private Const WH_CBT = 5 Private Const HCBT_ACTIVATE = 5 Private Const HC_ACTION = 0

Private hHook As Long

Public Function NewProc(ByVal lngCode As Long, _

ByVal wParam As Long, ByVal lParam As Long) As Long Dim RetVal

Dim strClassName As String, lngBuffer As Long

If lngCode < HC_ACTION Then

NewProc = CallNextHookEx(hHook, lngCode, wParam, lParam) Exit Function End If strClassName = String$(256, " ") lngBuffer = 255

If lngCode = HCBT_ACTIVATE Then 'A window has been activated

RetVal = GetClassName(wParam, strClassName, lngBuffer)

'Check for class name of the Inputbox If Left$(strClassName, RetVal) = "#32770" Then

'Change the edit control to display the password character *. 'You can change the Asc("*") as you please.

SendDlgItemMessage wParam, &H1324, EM_SETPASSWORDCHAR, Asc("*"), &H0 End If

End If

'This line will ensure that any other hooks that may be in place are 'called correctly.

CallNextHookEx hHook, lngCode, wParam, lParam End Function

Public Function InputBoxDK(Prompt, Optional Title, _

Optional Default, Optional XPos, _ Optional YPos, Optional HelpFile, Optional Context) As String Dim lngModHwnd As Long, lngThreadID As Long lngThreadID = GetCurrentThreadId lngModHwnd = GetModuleHandle(vbNullString)

hHook = SetWindowsHookEx(WH_CBT, AddressOf NewProc, lngModHwnd, lngThreadID) On Error Resume Next

InputBoxDK = InputBox(Prompt, Title, Default, XPos, YPos, HelpFile, Context) UnhookWindowsHookEx hHook

End Function Sub PasswordBox()

If InputBoxDK("Please enter password", "Password Required") <> "password" Then MsgBox "Sorry, that was not a correct password."

Else

MsgBox "Correct Password! Come on in." End If End Sub

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