readme.txt

SimpleLAP源码的配套设置和调用代码

Q314989 - Let Me In: Pocket PC Password User Interface Redirect Sample 

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The information in this article applies to:

Microsoft Windows CE Platform SDK for Pocket PC 2002 
Microsoft Windows CE Platform SDK for Pocket PC

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OVERVIEW
-------
This articles describes what you need to implement a custom password 
applet (redirect) for a Pocket PC device, and sample code to demonstrate the 
concepts. 

NOTE: The power-on password functionality may not function predictably 
on some devices. This is because the original equipment manufacturer of the 
device may change the Startui component in some ways, which may change its 
behavior or your ability to modify the component.

The "Let Me In" sample replaces the standard Pocket PC password user interface 
with a doodle grid. You can specify a pattern connecting the grid points by 
drawing on the grid in the settings applet. Once enabled, the pattern must be 
entered when the device is powered-on before any other tasks can be performed. 


Creating a Password Applet Redirect
-----------------------------------

To create a password applet replacement, follow these steps: 

1. Create a DLL project that outputs a module named Password.cpl.

2. Implement and export the CPlApplet() function to create the new Control 
   Panel applet. Use the CheckPassword function, the SetPassword function, and 
   SetPasswordActive function to set the platform password settings. Use 
   this password for two things that must be considered:

   a. The ActiveSync desktop component can request this password when 
      the device tries to connect.

   b. The device can request this password at power-on before any other 
      operations can be performed.


3. Implement and export the PromptForPasswd() function. This function 
displays the power-on password interface.


4. Create a .cpl file association in the device registry. This is required 
   for some other critical registry keys to work correctly:

   [HKCR\.cpl]
   (default) = "cplfile"

   [HKCR\cplfile\Shell\Open\Command]
   (default) = "\Windows\ctlpnl.exe %1" 

   Microsoft also recommends the following optional keys for completeness: 

   [HKCR\cplfile]
   (default) = "<description>"

   [HKCR\cplfile\DefaultIcon]
   (default) = "<module-name>,<icon-resource-id>" 

5. Set the location of the redirect password module in the device registry. 

   [HKLM\ControlPanel\Password]
   "Redirect" = "\windows\password.cpl" 

   NOTE: You must name the module "password.cpl" for the module to be 
   backward compatible with earlier versions of the Pocket PC platform.

7. NEW TO POCKET PC 2002: set the password request timeout policy in the 
   device registry:

   [HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Shell]
   "ActivePeriod"=DWORD:<minutes> 

   This minutes value determines how long the device must be off continuously 
   before power-on prompts for the password again. A value of 0 (zero) indicates 
   that the device should always prompt for the password. The control panel 
   applet can provide a user interface to make this user configurable.

   NOTE: If this value is not 0 (zero), and you fail to leave the device off 
   for the specified period of time, the password dialog does not appear when 
   you resume the device.


Special Functions
-----------------

SetPassword

   This Pocket PC function sets the system password to a new string. 

   BOOL SetPassword( 
   LPWSTR lpszOldPassword, 
   LPWSTR lpszNewPassword ); 

Parameters

   lpszOldPassword

   The current device password. This determines 
   whether the user or application has permission to call this 
   function. Specify NULL if there currently is no password set.

   lpszNewPassword

   The desired new password. Specify NULL to remove 
   the current password without setting a new one.

Return Values

   TRUE indicates that the change of password was successful. 
   FALSE indicates that the change of password was not successful.
 

SetPasswordActive

   This Pocket PC function enables or disables the password. 

   BOOL SetPasswordActive( 
   BOOL bActive, 
   LPWSTR lpszPassword ); 

Parameters

   bActive

   TRUE enables the password. 
   FALSE disables the password.


   lpszPassword

   The current device password. This determines 
   whether the user or application has permission to call this function.

Return Values

   TRUE indicates that activating the password was successful. 
   FALSE indicates that activating the password was not successful.

   When active, this password can be used by the Startui component 
   and ActiveSync to control access to the device. In the case of 
   ActiveSync, this function results in a password prompt that 
   appears on the desktop. The Startui component prompts for this 
   password if the power-on password is enabled by means of the 
   following registry setting: 

   [HKCU\ControlPanel\Owner]
   "PowrPass"=REG_BINARY:<flag-byte> 

   A flag-byte value of 0x01 enables the power-on prompt. A value 
   of 0x00 disables the power-on prompt. 


GetPasswordActive

   This Pocket PC function indicates whether the current password 
   is active. 

   BOOL GetPasswordActive( void ); 

Return Values

   TRUE indicates that the password is active. 
   FALSE indicates that the password is not active.


PromptForPasswd

   This function is implemented by the password redirect module and 
   is called by the operating system to prompt the user for a password. 

   LPTSTR PromptForPasswd( 
   HWND hwndParent, 
   BOOL fTightSecurity ); 

Parameters

   hwndParent

   The handle of the parent window. Make any password window 
   a descendant of this window.

   fTightSecurity
 
   Always set this to TRUE. This parameter is 
   currently reserved.

Return Values

   A password string that will be validated by the operating system. 
   This string must be allocated with LocalAlloc and will be freed by 
   the operating system.