普通的程序中. 鼠标事件监听
要监听鼠标事件，你可以使用QMouseEvent类，它提供了多种类型的鼠标事件，如QMouseEvent::MouseButtonPress、QMouseEvent::MouseButtonRelease、QMouseEvent::MouseMove等。
但是离开程序后就很难监听到，这里就需要用到系统api来监听

#include "globalkeyevent.h"
#if defined(Q_OS_WIN)
#include "Windows.h"
#include <QDebug>
#include <QKeyEvent>enum WindowsNativeModifiers {ShiftLeft            = 0x00000001,ControlLeft          = 0x00000002,AltLeft              = 0x00000004,MetaLeft             = 0x00000008,ShiftRight           = 0x00000010,ControlRight         = 0x00000020,AltRight             = 0x00000040,MetaRight            = 0x00000080,CapsLock             = 0x00000100,NumLock              = 0x00000200,ScrollLock           = 0x00000400,ExtendedKey          = 0x01000000,// Convenience mappingsShiftAny             = 0x00000011,ControlAny           = 0x00000022,AltAny               = 0x00000044,MetaAny              = 0x00000088,LockAny              = 0x00000700
};// 值的含义:
// 0           = 字符输出键，需要键盘驱动程序映射
// Key_unknown = 未知虚拟密钥，无法转换，忽略
// Windows 到 Qt::Key映射表，在"D:\Qt\Qt5.12.5\5.12.5\Src\qtbase\src\plugins\platforms\windows\qwindowskeymapper.cpp"中有
static const uint KeyTbl[] = { // Keyboard mapping table// Dec |  Hex | Windows Virtual keyQt::Key_unknown,    //   0   0x00Qt::Key_unknown,    //   1   0x01   VK_LBUTTON          | Left mouse buttonQt::Key_unknown,    //   2   0x02   VK_RBUTTON          | Right mouse buttonQt::Key_Cancel,     //   3   0x03   VK_CANCEL           | Control-Break processingQt::Key_unknown,    //   4   0x04   VK_MBUTTON          | Middle mouse buttonQt::Key_unknown,    //   5   0x05   VK_XBUTTON1         | X1 mouse buttonQt::Key_unknown,    //   6   0x06   VK_XBUTTON2         | X2 mouse buttonQt::Key_unknown,    //   7   0x07   -- unassigned --Qt::Key_Backspace,  //   8   0x08   VK_BACK             | BackSpace keyQt::Key_Tab,        //   9   0x09   VK_TAB              | Tab keyQt::Key_unknown,    //  10   0x0A   -- reserved --Qt::Key_unknown,    //  11   0x0B   -- reserved --Qt::Key_Clear,      //  12   0x0C   VK_CLEAR            | Clear keyQt::Key_Return,     //  13   0x0D   VK_RETURN           | Enter keyQt::Key_unknown,    //  14   0x0E   -- unassigned --Qt::Key_unknown,    //  15   0x0F   -- unassigned --Qt::Key_Shift,      //  16   0x10   VK_SHIFT            | Shift keyQt::Key_Control,    //  17   0x11   VK_CONTROL          | Ctrl keyQt::Key_Alt,        //  18   0x12   VK_MENU             | Alt keyQt::Key_Pause,      //  19   0x13   VK_PAUSE            | Pause keyQt::Key_CapsLock,   //  20   0x14   VK_CAPITAL          | Caps-LockQt::Key_unknown,    //  21   0x15   VK_KANA / VK_HANGUL | IME Kana or Hangul modeQt::Key_unknown,    //  22   0x16   -- unassigned --Qt::Key_unknown,    //  23   0x17   VK_JUNJA            | IME Junja modeQt::Key_unknown,    //  24   0x18   VK_FINAL            | IME final modeQt::Key_unknown,    //  25   0x19   VK_HANJA / VK_KANJI | IME Hanja or Kanji modeQt::Key_unknown,    //  26   0x1A   -- unassigned --Qt::Key_Escape,     //  27   0x1B   VK_ESCAPE           | Esc keyQt::Key_unknown,    //  28   0x1C   VK_CONVERT          | IME convertQt::Key_unknown,    //  29   0x1D   VK_NONCONVERT       | IME non-convertQt::Key_unknown,    //  30   0x1E   VK_ACCEPT           | IME acceptQt::Key_Mode_switch,//  31   0x1F   VK_MODECHANGE       | IME mode change requestQt::Key_Space,      //  32   0x20   VK_SPACE            | SpacebarQt::Key_PageUp,     //  33   0x21   VK_PRIOR            | Page Up keyQt::Key_PageDown,   //  34   0x22   VK_NEXT             | Page Down keyQt::Key_End,        //  35   0x23   VK_END              | End keyQt::Key_Home,       //  36   0x24   VK_HOME             | Home keyQt::Key_Left,       //  37   0x25   VK_LEFT             | Left arrow keyQt::Key_Up,         //  38   0x26   VK_UP               | Up arrow keyQt::Key_Right,      //  39   0x27   VK_RIGHT            | Right arrow keyQt::Key_Down,       //  40   0x28   VK_DOWN             | Down arrow keyQt::Key_Select,     //  41   0x29   VK_SELECT           | Select keyQt::Key_Printer,    //  42   0x2A   VK_PRINT            | Print keyQt::Key_Execute,    //  43   0x2B   VK_EXECUTE          | Execute keyQt::Key_Print,      //  44   0x2C   VK_SNAPSHOT         | Print Screen keyQt::Key_Insert,     //  45   0x2D   VK_INSERT           | Ins keyQt::Key_Delete,     //  46   0x2E   VK_DELETE           | Del keyQt::Key_Help,       //  47   0x2F   VK_HELP             | Help key0,                  //  48   0x30   (VK_0)              | 0 key0,                  //  49   0x31   (VK_1)              | 1 key0,                  //  50   0x32   (VK_2)              | 2 key0,                  //  51   0x33   (VK_3)              | 3 key0,                  //  52   0x34   (VK_4)              | 4 key0,                  //  53   0x35   (VK_5)              | 5 key0,                  //  54   0x36   (VK_6)              | 6 key0,                  //  55   0x37   (VK_7)              | 7 key0,                  //  56   0x38   (VK_8)              | 8 key0,                  //  57   0x39   (VK_9)              | 9 keyQt::Key_unknown,    //  58   0x3A   -- unassigned --Qt::Key_unknown,    //  59   0x3B   -- unassigned --Qt::Key_unknown,    //  60   0x3C   -- unassigned --Qt::Key_unknown,    //  61   0x3D   -- unassigned --Qt::Key_unknown,    //  62   0x3E   -- unassigned --Qt::Key_unknown,    //  63   0x3F   -- unassigned --Qt::Key_unknown,    //  64   0x40   -- unassigned --0,                  //  65   0x41   (VK_A)              | A key0,                  //  66   0x42   (VK_B)              | B key0,                  //  67   0x43   (VK_C)              | C key0,                  //  68   0x44   (VK_D)              | D key0,                  //  69   0x45   (VK_E)              | E key0,                  //  70   0x46   (VK_F)              | F key0,                  //  71   0x47   (VK_G)              | G key0,                  //  72   0x48   (VK_H)              | H key0,                  //  73   0x49   (VK_I)              | I key0,                  //  74   0x4A   (VK_J)              | J key0,                  //  75   0x4B   (VK_K)              | K key0,                  //  76   0x4C   (VK_L)              | L key0,                  //  77   0x4D   (VK_M)              | M key0,                  //  78   0x4E   (VK_N)              | N key0,                  //  79   0x4F   (VK_O)              | O key0,                  //  80   0x50   (VK_P)              | P key0,                  //  81   0x51   (VK_Q)              | Q key0,                  //  82   0x52   (VK_R)              | R key0,                  //  83   0x53   (VK_S)              | S key0,                  //  84   0x54   (VK_T)              | T key0,                  //  85   0x55   (VK_U)              | U key0,                  //  86   0x56   (VK_V)              | V key0,                  //  87   0x57   (VK_W)              | W key0,                  //  88   0x58   (VK_X)              | X key0,                  //  89   0x59   (VK_Y)              | Y key0,                  //  90   0x5A   (VK_Z)              | Z keyQt::Key_Meta,       //  91   0x5B   VK_LWIN             | Left Windows  - MS Natural kbdQt::Key_Meta,       //  92   0x5C   VK_RWIN             | Right Windows - MS Natural kbdQt::Key_Menu,       //  93   0x5D   VK_APPS             | Application key-MS Natural kbdQt::Key_unknown,    //  94   0x5E   -- reserved --Qt::Key_Sleep,      //  95   0x5F   VK_SLEEPQt::Key_0,          //  96   0x60   VK_NUMPAD0          | Numeric keypad 0 keyQt::Key_1,          //  97   0x61   VK_NUMPAD1          | Numeric keypad 1 keyQt::Key_2,          //  98   0x62   VK_NUMPAD2          | Numeric keypad 2 keyQt::Key_3,          //  99   0x63   VK_NUMPAD3          | Numeric keypad 3 keyQt::Key_4,          // 100   0x64   VK_NUMPAD4          | Numeric keypad 4 keyQt::Key_5,          // 101   0x65   VK_NUMPAD5          | Numeric keypad 5 keyQt::Key_6,          // 102   0x66   VK_NUMPAD6          | Numeric keypad 6 keyQt::Key_7,          // 103   0x67   VK_NUMPAD7          | Numeric keypad 7 keyQt::Key_8,          // 104   0x68   VK_NUMPAD8          | Numeric keypad 8 keyQt::Key_9,          // 105   0x69   VK_NUMPAD9          | Numeric keypad 9 keyQt::Key_Asterisk,   // 106   0x6A   VK_MULTIPLY         | Multiply keyQt::Key_Plus,       // 107   0x6B   VK_ADD              | Add keyQt::Key_unknown,    // 108   0x6C   VK_SEPARATOR        | Separator key (locale-dependent)Qt::Key_Minus,      // 109   0x6D   VK_SUBTRACT         | Subtract keyQt::Key_unknown,    // 110   0x6E   VK_DECIMAL          | Decimal key (locale-dependent)Qt::Key_Slash,      // 111   0x6F   VK_DIVIDE           | Divide keyQt::Key_F1,         // 112   0x70   VK_F1               | F1 keyQt::Key_F2,         // 113   0x71   VK_F2               | F2 keyQt::Key_F3,         // 114   0x72   VK_F3               | F3 keyQt::Key_F4,         // 115   0x73   VK_F4               | F4 keyQt::Key_F5,         // 116   0x74   VK_F5               | F5 keyQt::Key_F6,         // 117   0x75   VK_F6               | F6 keyQt::Key_F7,         // 118   0x76   VK_F7               | F7 keyQt::Key_F8,         // 119   0x77   VK_F8               | F8 keyQt::Key_F9,         // 120   0x78   VK_F9               | F9 keyQt::Key_F10,        // 121   0x79   VK_F10              | F10 keyQt::Key_F11,        // 122   0x7A   VK_F11              | F11 keyQt::Key_F12,        // 123   0x7B   VK_F12              | F12 keyQt::Key_F13,        // 124   0x7C   VK_F13              | F13 keyQt::Key_F14,        // 125   0x7D   VK_F14              | F14 keyQt::Key_F15,        // 126   0x7E   VK_F15              | F15 keyQt::Key_F16,        // 127   0x7F   VK_F16              | F16 keyQt::Key_F17,        // 128   0x80   VK_F17              | F17 keyQt::Key_F18,        // 129   0x81   VK_F18              | F18 keyQt::Key_F19,        // 130   0x82   VK_F19              | F19 keyQt::Key_F20,        // 131   0x83   VK_F20              | F20 keyQt::Key_F21,        // 132   0x84   VK_F21              | F21 keyQt::Key_F22,        // 133   0x85   VK_F22              | F22 keyQt::Key_F23,        // 134   0x86   VK_F23              | F23 keyQt::Key_F24,        // 135   0x87   VK_F24              | F24 keyQt::Key_unknown,    // 136   0x88   -- unassigned --Qt::Key_unknown,    // 137   0x89   -- unassigned --Qt::Key_unknown,    // 138   0x8A   -- unassigned --Qt::Key_unknown,    // 139   0x8B   -- unassigned --Qt::Key_unknown,    // 140   0x8C   -- unassigned --Qt::Key_unknown,    // 141   0x8D   -- unassigned --Qt::Key_unknown,    // 142   0x8E   -- unassigned --Qt::Key_unknown,    // 143   0x8F   -- unassigned --Qt::Key_NumLock,    // 144   0x90   VK_NUMLOCK          | Num Lock keyQt::Key_ScrollLock, // 145   0x91   VK_SCROLL           | Scroll Lock key// Fujitsu/OASYS kbd --------------------0, //Qt::Key_Jisho, // 146   0x92   VK_OEM_FJ_JISHO     | 'Dictionary' key ///              VK_OEM_NEC_EQUAL  = key on numpad on NEC PC-9800 kbdQt::Key_Massyo,     // 147   0x93   VK_OEM_FJ_MASSHOU   | 'Unregister word' keyQt::Key_Touroku,    // 148   0x94   VK_OEM_FJ_TOUROKU   | 'Register word' key0, //Qt::Key_Oyayubi_Left,//149   0x95  VK_OEM_FJ_LOYA  | 'Left OYAYUBI' key0, //Qt::Key_Oyayubi_Right,//150  0x96  VK_OEM_FJ_ROYA  | 'Right OYAYUBI' keyQt::Key_unknown,    // 151   0x97   -- unassigned --Qt::Key_unknown,    // 152   0x98   -- unassigned --Qt::Key_unknown,    // 153   0x99   -- unassigned --Qt::Key_unknown,    // 154   0x9A   -- unassigned --Qt::Key_unknown,    // 155   0x9B   -- unassigned --Qt::Key_unknown,    // 156   0x9C   -- unassigned --Qt::Key_unknown,    // 157   0x9D   -- unassigned --Qt::Key_unknown,    // 158   0x9E   -- unassigned --Qt::Key_unknown,    // 159   0x9F   -- unassigned --Qt::Key_Shift,      // 160   0xA0   VK_LSHIFT           | Left Shift keyQt::Key_Shift,      // 161   0xA1   VK_RSHIFT           | Right Shift keyQt::Key_Control,    // 162   0xA2   VK_LCONTROL         | Left Ctrl keyQt::Key_Control,    // 163   0xA3   VK_RCONTROL         | Right Ctrl keyQt::Key_Alt,        // 164   0xA4   VK_LMENU            | Left Menu keyQt::Key_Alt,        // 165   0xA5   VK_RMENU            | Right Menu keyQt::Key_Back,       // 166   0xA6   VK_BROWSER_BACK     | Browser Back keyQt::Key_Forward,    // 167   0xA7   VK_BROWSER_FORWARD  | Browser Forward keyQt::Key_Refresh,    // 168   0xA8   VK_BROWSER_REFRESH  | Browser Refresh keyQt::Key_Stop,       // 169   0xA9   VK_BROWSER_STOP     | Browser Stop keyQt::Key_Search,     // 170   0xAA   VK_BROWSER_SEARCH   | Browser Search keyQt::Key_Favorites,  // 171   0xAB   VK_BROWSER_FAVORITES| Browser Favorites keyQt::Key_HomePage,   // 172   0xAC   VK_BROWSER_HOME     | Browser Start and Home keyQt::Key_VolumeMute, // 173   0xAD   VK_VOLUME_MUTE      | Volume Mute keyQt::Key_VolumeDown, // 174   0xAE   VK_VOLUME_DOWN      | Volume Down keyQt::Key_VolumeUp,   // 175   0xAF   VK_VOLUME_UP        | Volume Up keyQt::Key_MediaNext,  // 176   0xB0   VK_MEDIA_NEXT_TRACK | Next Track keyQt::Key_MediaPrevious, //177 0xB1   VK_MEDIA_PREV_TRACK | Previous Track keyQt::Key_MediaStop,  // 178   0xB2   VK_MEDIA_STOP       | Stop Media keyQt::Key_MediaPlay,  // 179   0xB3   VK_MEDIA_PLAY_PAUSE | Play/Pause Media keyQt::Key_LaunchMail, // 180   0xB4   VK_LAUNCH_MAIL      | Start Mail keyQt::Key_LaunchMedia,// 181   0xB5   VK_LAUNCH_MEDIA_SELECT Select Media keyQt::Key_Launch0,    // 182   0xB6   VK_LAUNCH_APP1      | Start Application 1 keyQt::Key_Launch1,    // 183   0xB7   VK_LAUNCH_APP2      | Start Application 2 keyQt::Key_unknown,    // 184   0xB8   -- reserved --Qt::Key_unknown,    // 185   0xB9   -- reserved --0,                  // 186   0xBA   VK_OEM_1            | ';:' for US0,                  // 187   0xBB   VK_OEM_PLUS         | '+' any country0,                  // 188   0xBC   VK_OEM_COMMA        | ',' any country0,                  // 189   0xBD   VK_OEM_MINUS        | '-' any country0,                  // 190   0xBE   VK_OEM_PERIOD       | '.' any country0,                  // 191   0xBF   VK_OEM_2            | '/?' for US0,                  // 192   0xC0   VK_OEM_3            | '`~' for USQt::Key_unknown,    // 193   0xC1   -- reserved --Qt::Key_unknown,    // 194   0xC2   -- reserved --Qt::Key_unknown,    // 195   0xC3   -- reserved --Qt::Key_unknown,    // 196   0xC4   -- reserved --Qt::Key_unknown,    // 197   0xC5   -- reserved --Qt::Key_unknown,    // 198   0xC6   -- reserved --Qt::Key_unknown,    // 199   0xC7   -- reserved --Qt::Key_unknown,    // 200   0xC8   -- reserved --Qt::Key_unknown,    // 201   0xC9   -- reserved --Qt::Key_unknown,    // 202   0xCA   -- reserved --Qt::Key_unknown,    // 203   0xCB   -- reserved --Qt::Key_unknown,    // 204   0xCC   -- reserved --Qt::Key_unknown,    // 205   0xCD   -- reserved --Qt::Key_unknown,    // 206   0xCE   -- reserved --Qt::Key_unknown,    // 207   0xCF   -- reserved --Qt::Key_unknown,    // 208   0xD0   -- reserved --Qt::Key_unknown,    // 209   0xD1   -- reserved --Qt::Key_unknown,    // 210   0xD2   -- reserved --Qt::Key_unknown,    // 211   0xD3   -- reserved --Qt::Key_unknown,    // 212   0xD4   -- reserved --Qt::Key_unknown,    // 213   0xD5   -- reserved --Qt::Key_unknown,    // 214   0xD6   -- reserved --Qt::Key_unknown,    // 215   0xD7   -- reserved --Qt::Key_unknown,    // 216   0xD8   -- unassigned --Qt::Key_unknown,    // 217   0xD9   -- unassigned --Qt::Key_unknown,    // 218   0xDA   -- unassigned --0,                  // 219   0xDB   VK_OEM_4            | '[{' for US0,                  // 220   0xDC   VK_OEM_5            | '\|' for US0,                  // 221   0xDD   VK_OEM_6            | ']}' for US0,                  // 222   0xDE   VK_OEM_7            | ''"' for US0,                  // 223   0xDF   VK_OEM_8Qt::Key_unknown,    // 224   0xE0   -- reserved --Qt::Key_unknown,    // 225   0xE1   VK_OEM_AX           | 'AX' key on Japanese AX kbdQt::Key_unknown,    // 226   0xE2   VK_OEM_102          | "<>" or "\|" on RT 102-key kbdQt::Key_unknown,    // 227   0xE3   VK_ICO_HELP         | Help key on ICOQt::Key_unknown,    // 228   0xE4   VK_ICO_00           | 00 key on ICOQt::Key_unknown,    // 229   0xE5   VK_PROCESSKEY       | IME Process keyQt::Key_unknown,    // 230   0xE6   VK_ICO_CLEAR        |Qt::Key_unknown,    // 231   0xE7   VK_PACKET           | Unicode char as keystrokesQt::Key_unknown,    // 232   0xE8   -- unassigned --// Nokia/Ericsson definitions ---------------Qt::Key_unknown,    // 233   0xE9   VK_OEM_RESETQt::Key_unknown,    // 234   0xEA   VK_OEM_JUMPQt::Key_unknown,    // 235   0xEB   VK_OEM_PA1Qt::Key_unknown,    // 236   0xEC   VK_OEM_PA2Qt::Key_unknown,    // 237   0xED   VK_OEM_PA3Qt::Key_unknown,    // 238   0xEE   VK_OEM_WSCTRLQt::Key_unknown,    // 239   0xEF   VK_OEM_CUSELQt::Key_unknown,    // 240   0xF0   VK_OEM_ATTNQt::Key_unknown,    // 241   0xF1   VK_OEM_FINISHQt::Key_unknown,    // 242   0xF2   VK_OEM_COPYQt::Key_unknown,    // 243   0xF3   VK_OEM_AUTOQt::Key_unknown,    // 244   0xF4   VK_OEM_ENLWQt::Key_unknown,    // 245   0xF5   VK_OEM_BACKTABQt::Key_unknown,    // 246   0xF6   VK_ATTN             | Attn keyQt::Key_unknown,    // 247   0xF7   VK_CRSEL            | CrSel keyQt::Key_unknown,    // 248   0xF8   VK_EXSEL            | ExSel keyQt::Key_unknown,    // 249   0xF9   VK_EREOF            | Erase EOF keyQt::Key_Play,       // 250   0xFA   VK_PLAY             | Play keyQt::Key_Zoom,       // 251   0xFB   VK_ZOOM             | Zoom keyQt::Key_unknown,    // 252   0xFC   VK_NONAME           | ReservedQt::Key_unknown,    // 253   0xFD   VK_PA1              | PA1 keyQt::Key_Clear,      // 254   0xFE   VK_OEM_CLEAR        | Clear key0
};static inline quint32 winceKeyBend(quint32 keyCode)
{return KeyTbl[keyCode];
}/*** @brief  获取是否按下键盘修饰键，例如Ctrl、shirt等* @return*/
static inline Qt::KeyboardModifiers queryKeyboardModifiers()
{Qt::KeyboardModifiers modifiers = Qt::NoModifier;if (GetKeyState(VK_SHIFT) < 0)modifiers |= Qt::ShiftModifier;if (GetKeyState(VK_CONTROL) < 0)modifiers |= Qt::ControlModifier;if (GetKeyState(VK_MENU) < 0)modifiers |= Qt::AltModifier;if (GetKeyState(VK_LWIN) < 0 || GetKeyState(VK_RWIN) < 0)modifiers |= Qt::MetaModifier;return modifiers;
}static uchar g_buffer[256];
/*** @brief            将VK转换为Qt键代码或unicode字符* @param vk* @param scancode* @param g_buffer* @param isDeadkey* @return*/
static inline quint32 toKeyOrUnicode(quint32 vk, quint32 scancode, bool *isDeadkey = nullptr)
{Q_ASSERT(vk > 0 && vk < 256);GetKeyboardState(g_buffer);   // // 将 256 个虚拟密钥的状态复制到指定的缓冲区。
//    qDebug() <<"vk " << (g_buffer[vk] & 0x80);g_buffer[VK_LWIN    ] = 0;g_buffer[VK_RWIN    ] = 0;g_buffer[VK_CAPITAL ] = 0;g_buffer[VK_NUMLOCK ] = 0;g_buffer[VK_SCROLL  ] = 0;// 始终为0，因为我们只会更改其他版本g_buffer[VK_RSHIFT  ] = 0;g_buffer[VK_RCONTROL] = 0;g_buffer[VK_LMENU   ] = 0;   // 使用右Alt，因为左Ctrl+右Alt被视为AltGraphg_buffer[VK_CONTROL ] = 0;   // 需要将ctrl键清空，否则按住Ctrl + 字母键会出现无法返回正确值的情况quint32 code = 0;QChar unicodeBuffer[5];int res = ToUnicode(vk, scancode, g_buffer, reinterpret_cast<LPWSTR>(unicodeBuffer), 5, 0);// 使用Ctrl修饰符时，ToUnicode不会返回正确的值。为了分配右键，如果上一次调用失败，则仅删除该函数的控制修饰符。if (res == 0 && g_buffer[VK_CONTROL]){const unsigned char controlState = g_buffer[VK_CONTROL];g_buffer[VK_CONTROL] = 0;res = ToUnicode(vk, scancode, g_buffer, reinterpret_cast<LPWSTR>(unicodeBuffer), 5, 0);g_buffer[VK_CONTROL] = controlState;}if (res){code = unicodeBuffer[0].toUpper().unicode();   // 将字符转换位Qt::Key值}// Qt:：Key_*的编码不低于0x20，因此请重试，DEL键（0x7f）使用正确的Qt::Key_ codeif (code < 0x20 || code == 0x7f) // Handles res==0 too{code = winceKeyBend(vk);}if (isDeadkey){*isDeadkey = (res == -1);}return code == Qt::Key_unknown ? 0 : code;
}static uchar g_keyState[256];
/*** @brief           获取当前按下键的字符* @param vk        要转换的虚拟密钥代码* @param scancode  要转换的密钥的硬件扫描代码* @return*/
static inline QString getKeyText(quint32 vk, quint32 scancode)
{GetKeyboardState(g_keyState);                                     // 将 256 个虚拟密钥的状态复制到指定的缓冲区。wchar_t newKey[3] = {0};// 将指定的虚拟键代码和键盘状态转换为相应的一个或多个 Unicode 字符。int ret = ToUnicode(vk,           // 要转换的虚拟密钥代码scancode,     // 要转换的密钥的硬件扫描代码g_keyState,   // 指向包含当前键盘状态的 256 字节数组的指针。数组中的每个元素（字节）都包含一个键的状态。newKey,       // 接收转换后的一个或多个 Unicode 字符的缓冲区3,            // 参数指向的缓冲区的大小（以字符为单位）0);           // 函数的行为。0：则菜单处于活动状态； 2，则不会更改键盘状态（Windows 10 版本 1607 及更高版本）if (ret == 1)      // 1：一个字符被写入 newKey{QChar uch = QChar(newKey[0]);return  uch;}else        // 无法获取到字符{return QString();}
}/*** @brief        获取本机修改器值* @param flags* @return*/
static quint32 getNativeModifiers(quint32 flags)
{quint32 nModifiers = 0;// 将本机修改器映射到某些位表示nModifiers |= (GetKeyState(VK_LSHIFT  ) & 0x80 ? ShiftLeft : 0);nModifiers |= (GetKeyState(VK_RSHIFT  ) & 0x80 ? ShiftRight : 0);nModifiers |= (GetKeyState(VK_LCONTROL) & 0x80 ? ControlLeft : 0);nModifiers |= (GetKeyState(VK_RCONTROL) & 0x80 ? ControlRight : 0);nModifiers |= (GetKeyState(VK_LMENU   ) & 0x80 ? AltLeft : 0);nModifiers |= (GetKeyState(VK_RMENU   ) & 0x80 ? AltRight : 0);nModifiers |= (GetKeyState(VK_LWIN    ) & 0x80 ? MetaLeft : 0);nModifiers |= (GetKeyState(VK_RWIN    ) & 0x80 ? MetaRight : 0);// 将锁定键添加到相同的位nModifiers |= (GetKeyState(VK_CAPITAL ) & 0x01 ? CapsLock : 0);nModifiers |= (GetKeyState(VK_NUMLOCK ) & 0x01 ? NumLock : 0);nModifiers |= (GetKeyState(VK_SCROLL  ) & 0x01 ? ScrollLock : 0);if (flags & LLKHF_EXTENDED)   // 使用扩展键，例如：Home End pgUP pgDn{nModifiers |= ExtendedKey;}return nModifiers;
}static HHOOK g_hook = nullptr;
/*** @brief           处理鼠标事件的回调函数，由于这不是一个成员函数，所以需要通过中间单例类mouseEvent将鼠标信号传递出来*                  具体内容看https://learn.microsoft.com/zh-cn/previous-versions/windows/desktop/legacy/ms644986(v=vs.85)* @param nCode     挂钩过程用于确定如何处理消息的代码。如果nCode小于零，则挂钩过程必须将消息传递给 CallNextHookEx 函数而不进行进一步处理，并且应返回CallNextHookEx返回的值* @param wParam    信号类型：WM_KEYDOWN、WM_KEYUP、WM_SYSKEYDOWN或WM_SYSKEYUP* @param lParam    MSLLHOOKSTRUCT结构体指针* @return*/
LRESULT CALLBACK LowLevelKeyboardProc(int nCode, WPARAM wParam, LPARAM lParam)
{KBDLLHOOKSTRUCT * kbdll = reinterpret_cast<KBDLLHOOKSTRUCT*>(lParam);bool isDeadKey                  = false;Qt::KeyboardModifiers modifiers = queryKeyboardModifiers();int                   key       = int(toKeyOrUnicode(kbdll->vkCode, kbdll->scanCode, &isDeadKey));QString               text      = getKeyText(kbdll->vkCode, kbdll->scanCode);quint32         nativeModifiers = getNativeModifiers(kbdll->flags);bool                  autorep   = (g_buffer[kbdll->vkCode] & 0x80);switch (wParam){case WM_KEYDOWN:      // 按下非系统键， 非系统键是未按下 ALT 键时按下的键{emit GlobalKeyEvent::getInstance()->keyEvent(new QKeyEvent(QEvent::KeyPress, key, modifiers, kbdll->scanCode, kbdll->vkCode, nativeModifiers, text, autorep));break;}case WM_KEYUP:        // 当释放非系统键emit GlobalKeyEvent::getInstance()->keyEvent(new QKeyEvent(QEvent::KeyRelease, key, modifiers, kbdll->scanCode, kbdll->vkCode, nativeModifiers, text, !autorep));break;case WM_SYSKEYDOWN:   // 当用户按下 F10 键 (激活菜单栏) 或按住 Alt 键，然后按另一个键时，发布到具有键盘焦点的窗口qDebug() << "按下系统键 Alt";emit GlobalKeyEvent::getInstance()->keyEvent(new QKeyEvent(QEvent::KeyPress, key, modifiers, kbdll->scanCode, kbdll->vkCode, nativeModifiers, text, autorep));break;case WM_SYSKEYUP:     // 当用户释放按下 Alt 键时按下的键qDebug() << "释放系统键 Alt";emit GlobalKeyEvent::getInstance()->keyEvent(new QKeyEvent(QEvent::KeyRelease, key, modifiers, kbdll->scanCode, kbdll->vkCode, nativeModifiers, text, !autorep));break;default:break;}return CallNextHookEx(nullptr, nCode, wParam, lParam);   // 注意这一行一定不能少，否则会出大问题
}/*** @brief  安装全局鼠标事件监听器* @return*/
bool GlobalKeyEvent::installKeyEvent()
{if(g_hook) return true;     // 避免重复安装/*** WH_KEYBOARD_LL 为全局键盘钩子, WH_MOUSE_LL 为全局鼠标钩子* 详细说明看官方文档：https://learn.microsoft.com/zh-cn/windows/win32/api/winuser/nf-winuser-setwindowshookexw*/g_hook = SetWindowsHookExW(WH_KEYBOARD_LL, LowLevelKeyboardProc, GetModuleHandleW(nullptr), 0);return g_hook;
}/*** @brief   卸载全局鼠标事件监听器* @return*/
bool GlobalKeyEvent::removeKeyEvent()
{if(!g_hook) return true;   // 避免重复卸载bool ret = UnhookWindowsHookEx(g_hook);if(ret){g_hook = nullptr;return true;}return false;
}#endif