WinCE系统音量的设置

//========================================================================
//TITLE:
//    WinCE系统音量的设置
//AUTHOR:
//    norains
//DATE:
//    Sunday  8-April-2007
//Environment:
//        EVC4.0 + Standard SDK 4.2
//        EVC4.0 + Standard SDK 5.0
//========================================================================

首先我们来看一段最简单的改变音量的代码:
DWORD dwVolume = 0xAAAAAAAA; waveOutSetVolume(0,dwVolume); 
        
        waveOutSetVolume()的第一个参数是设备ID,因为需要更改的是整个系统音量,所以在这里直接取0值即可;第二个参数是需要设置的音量数值,范围是从 0x0 ~ 0xFFFFFFFF.
       
        但这个函数的功能却也是非常有限的,也就是说,它只能更改系统的主音量;如果想修改屏幕点击声,则就无能为力.
       
        有些细心的朋友会从"控制面板"的"声音"入手,发现每次在控制面板调节声音,相应的"ControlPanel/Volume"下的键值数值都会变更.但如果是直接修其下的改注册表,却是无论如何都达不到相应的功能的----因为没有通知系统,注册表已经被修改.
       
        如果需要告知系统,注册表已经修改,并请系统依照修改的数值来更改音量,则需要调用微软一个未公开的函数:AudioUpdateFromRegistry().
       
        这个函数在文档中是无法搜索到,如果需要调用这个函数,可以有两种方法.
       
        一是直接包含"pwinuser.h"文件,然后直接调用.
       
        二是调用coredll.dll库,引出该函数并使用.
       
        这里展示一个调用的例子:
typedef void (WINAPI *DLL_AUDIOUPDATEFROMREGISTRY)(); DLL_AUDIOUPDATEFROMREGISTRY Dll_AudioUpdateFromRegistry = NULL; HINSTANCE hCoreDll = LoadLibrary(TEXT("coredll.dll")); if (hCoreDll) ...{ Dll_AudioUpdateFromRegistry = (DLL_AUDIOUPDATEFROMREGISTRY)GetProcAddress(hCoreDll, _T("AudioUpdateFromRegistry")); if (Dll_AudioUpdateFromRegistry) ...{ (Dll_AudioUpdateFromRegistry)(); }  
        只要更新了注册表,然后调用该函数,则系统会根据键值来进行相应的调整.
       
        那么现在让我们来看看位于"ControlPanel/Volume"注册表中各键值的意义:
       
        Volume: 系统的主音量,范围是0x0 ~ 0xFFFFFFFF.
       
        Screen: 屏幕敲击声. 当数值为0时即为无声,1为柔和,65538为洪亮

        Key: 键盘敲击声,数值的意义和Screen相同.
       
        Mute: 控制其它静音的选项. 置0x04位为1时允许事件声音,0x02允许应用程序声音,0x01允许警告声.需要注意的是,如果不允许应用程序声音,则警告声位也将被忽略.
       
       
        如果每次更改音量都要改写注册表,调用动态链接库,会显得比较麻烦.为了写代码的便利,在此封装了这个声音的操作:
(注:CReg 请参见此篇文章:http://blog.youkuaiyun.com/norains/archive/2007/04/08/1556296.aspx)
////////////////////////////////////////////////////////////////////// // SysVolume.h: interface for the CSysVolume class. // //Version: // 1.0.0 //Date: // 2007.04.08 /**/////////////////////////////////////////////////////////////////////// #ifndef SYSVOLUME_H #define SYSVOLUME_H #include "Reg.h" //------------------------------------------------------------------------- //Macro define #define MIN_VOLUME 0 #define MAX_VOLUME 0xFFFFFFFF //------------------------------------------------------------------------- //Enum value enum VolumeModeType { VOL_SOFT, VOL_LOUD, VOL_MUTE }; //------------------------------------------------------------------------ class CSysVolume { public: BOOL SetVolumeScreenTap(VolumeModeType volMode); BOOL SetVolumeKeyClick(VolumeModeType volMode); BOOL EnableSoundNotification(BOOL bEnable); BOOL EnableSoundApplication(BOOL bEnable); BOOL EnableSoundEvent(BOOL bEnable); BOOL SetVolume(DWORD dwVol); CSysVolume(); virtual ~CSysVolume(); protected: BOOL Apply(); CReg m_Reg; }; #endif //#ifndef SYSVOLUME_H         
////////////////////////////////////////////////////////////////////// // SysVolume.cpp: implementation of the CSysVolume class. // /**/////////////////////////////////////////////////////////////////////// #include "stdafx.h" #include "SysVolume.h" //====================================================================== //Macro define //Registry KEY #define BASE_KEY HKEY_CURRENT_USER #define SUB_KEY TEXT("ControlPanel/Volume") #define VALUE_VOLUME TEXT("Volume") #define VALUE_SCREEN TEXT("Screen") #define VALUE_KEY TEXT("key") #define VALUE_MUTE TEXT("Mute") //For the screen tap and the key click #define VOL_VALUE_MUTE 0 #define VOL_VALUE_LOUD 65538 #define VOL_VALUE_SOFT 1 //The bit for sound #define BIT_EVENT 0x4 #define BIT_APPLICATION 0x2 #define BIT_NOTIFICATION 0x1 //====================================================================== /**/////////////////////////////////////////////////////////////////////// // Construction/Destruction /**/////////////////////////////////////////////////////////////////////// CSysVolume::CSysVolume() { m_Reg.Create(BASE_KEY, SUB_KEY); } CSysVolume::~CSysVolume() { } //--------------------------------------------------------------------- //Description: // Apply the volume //--------------------------------------------------------------------- BOOL CSysVolume::Apply() { typedef void (WINAPI *DLL_AUDIOUPDATEFROMREGISTRY)(); DLL_AUDIOUPDATEFROMREGISTRY Dll_AudioUpdateFromRegistry = NULL; HINSTANCE hCoreDll = LoadLibrary(TEXT("coredll.dll")); if (hCoreDll) { Dll_AudioUpdateFromRegistry = (DLL_AUDIOUPDATEFROMREGISTRY)GetProcAddress(hCoreDll, _T("AudioUpdateFromRegistry")); if (Dll_AudioUpdateFromRegistry) { (Dll_AudioUpdateFromRegistry)(); } else { return FALSE; } FreeLibrary(hCoreDll); } else { return FALSE; } return TRUE; } //--------------------------------------------------------------------- //Description: // Enable the sound for events //--------------------------------------------------------------------- BOOL CSysVolume::EnableSoundEvent(BOOL bEnable) { if(m_Reg.IsOK() != TRUE) { return FALSE; } DWORD dwVal = m_Reg.GetValueDW(VALUE_MUTE); if(bEnable == TRUE) { dwVal |= BIT_EVENT; } else { dwVal &= ~BIT_EVENT; } m_Reg.SetDW(VALUE_MUTE,dwVal); return Apply(); } //--------------------------------------------------------------------- //Description: // Enable the sound for application //--------------------------------------------------------------------- BOOL CSysVolume::EnableSoundApplication(BOOL bEnable) { if(m_Reg.IsOK() != TRUE) { return FALSE; } DWORD dwVal = m_Reg.GetValueDW(VALUE_MUTE); if(bEnable == TRUE) { dwVal |= BIT_APPLICATION; } else { dwVal &= ~BIT_APPLICATION; } m_Reg.SetDW(VALUE_MUTE,dwVal); return Apply(); } //--------------------------------------------------------------------- //Description: // Enable the sound for notifications. If the sound of application is //mute, the sound of notification is mute too. //--------------------------------------------------------------------- BOOL CSysVolume::EnableSoundNotification(BOOL bEnable) { if(m_Reg.IsOK() != TRUE) { return FALSE; } DWORD dwVal = m_Reg.GetValueDW(VALUE_MUTE); if(bEnable == TRUE) { dwVal |= BIT_NOTIFICATION; } else { dwVal &= ~BIT_NOTIFICATION; } m_Reg.SetDW(VALUE_MUTE,dwVal); return Apply(); } //--------------------------------------------------------------------- //Description: // Set the key click volume //--------------------------------------------------------------------- BOOL CSysVolume::SetVolumeKeyClick(VolumeModeType volMode) { DWORD dwVol = 0; switch(volMode) { case VOL_SOFT: dwVol = VOL_VALUE_SOFT; break; case VOL_LOUD: dwVol = VOL_VALUE_LOUD; break; case VOL_MUTE: dwVol = VOL_VALUE_MUTE; break; } if(m_Reg.IsOK() != TRUE) { return FALSE; } m_Reg.SetDW(VALUE_KEY,dwVol); return Apply(); } //--------------------------------------------------------------------- //Description: // Set the screen tap volume //--------------------------------------------------------------------- BOOL CSysVolume::SetVolumeScreenTap(VolumeModeType volMode) { DWORD dwVol = 0; switch(volMode) { case VOL_SOFT: dwVol = VOL_VALUE_SOFT; break; case VOL_LOUD: dwVol = VOL_VALUE_LOUD; break; case VOL_MUTE: dwVol = VOL_VALUE_MUTE; break; } if(m_Reg.IsOK() != TRUE) { return FALSE; } m_Reg.SetDW(VALUE_SCREEN,dwVol); return Apply(); } //--------------------------------------------------------------------- //Description: // Set the volume. // //Parameters: // dwVol: The volume to set. And the range is MIN_VOLUME ~ MAX_VOLUME //--------------------------------------------------------------------- BOOL CSysVolume::SetVolume(DWORD dwVol) { if(dwVol < MIN_VOLUME || dwVol > MAX_VOLUME) { return FALSE; } m_Reg.SetDW(VALUE_VOLUME,dwVol); return Apply(); }      

 

由于CSysVolume类将复杂的操作封装在内部,因此设置音量的非常简单.
以更改屏幕敲击声为洪亮为例:
CSysVolume sysVol; sysVol.SetVolumeScreenTap(VOL_LOUD);

原文作者：norains

原文地址：http://blog.youkuaiyun.com/norains/archive/2007/04/08/1556912.aspx