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Macos 使用IOHIDManager获取修改器键事件

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Macos 使用IOHIDManager获取修改器键事件,macos,keyboard,core-foundation,iokit,Macos,Keyboard,Core Foundation,Iokit,我试图使用IOHIDManager获取修改器键事件，因为缺少Cocoa flagsChanged事件（很难区分按下/释放，如果两个都关闭，则为左/右，等等）。下面是我创建管理器并注册回调的代码 IOHIDManagerRef hidManager = IOHIDManagerCreate(kCFAllocatorDefault, kIOHIDOptionsTypeNone); if (CFGetTypeID(hidManager) != IOHIDManagerGetTypeID

我试图使用IOHIDManager获取修改器键事件，因为缺少Cocoa flagsChanged事件（很难区分按下/释放，如果两个都关闭，则为左/右，等等）。下面是我创建管理器并注册回调的代码

IOHIDManagerRef hidManager = IOHIDManagerCreate(kCFAllocatorDefault,
        kIOHIDOptionsTypeNone);
if (CFGetTypeID(hidManager) != IOHIDManagerGetTypeID())
    return 1;

CFMutableDictionaryRef capsLock =
    myCreateDeviceMatchingDictionary(0x07, 0x39);
CFMutableDictionaryRef lctrl =
    myCreateDeviceMatchingDictionary(0x07, 0xE0);
CFMutableDictionaryRef lshift =
    myCreateDeviceMatchingDictionary(0x07, 0xE1);
CFMutableDictionaryRef lalt =
    myCreateDeviceMatchingDictionary(0x07, 0xE2);
CFMutableDictionaryRef lsuper =
    myCreateDeviceMatchingDictionary(0x07, 0xE3);
CFMutableDictionaryRef rctrl =
    myCreateDeviceMatchingDictionary(0x07, 0xE4);
CFMutableDictionaryRef rshift =
    myCreateDeviceMatchingDictionary(0x07, 0xE5);
CFMutableDictionaryRef ralt =
    myCreateDeviceMatchingDictionary(0x07, 0xE6);
CFMutableDictionaryRef rsuper =
    myCreateDeviceMatchingDictionary(0x07, 0xE7);

CFMutableDictionaryRef matchesList[] = {
    capsLock,
    lctrl,
    lshift,
    lalt,
    lsuper,
    rctrl,
    rshift,
    ralt,
    rsuper
};
CFArrayRef matches = CFArrayCreate(kCFAllocatorDefault,
        (const void **)matchesList, 9, NULL);
IOHIDManagerSetDeviceMatchingMultiple(hidManager, matches);

IOHIDManagerRegisterInputValueCallback(hidManager,
        myHandleModifiersCallback, NULL);

IOHIDManagerScheduleWithRunLoop(hidManager, CFRunLoopGetMain(),
        kCFRunLoopDefaultMode);

IOHIDManagerOpen(hidManager, kIOHIDOptionsTypeNone);
但是，回调从未运行过。我遗漏了什么吗

我不完全理解HID使用页面，因此我不知道是否使用带有键盘使用ID（06）的通用桌面页面（0x01）或带有单个按键使用ID的键盘/键盘页面（0x07）。也许这与此有关吧？

我想出来了。方法是使用通用桌面页面（0x01）键盘（06）（完整性方面使用键盘（07））与IOHIDManagerSetDeviceMatchingMultiple一起使用，然后输入值回调获取键盘/键盘使用页面（0x07）内容

例如，要为所有键盘/键盘设置HIDManager，可以执行以下操作：

IOHIDManagerRef hidManager = IOHIDManagerCreate(kCFAllocatorDefault,
        kIOHIDOptionsTypeNone);

CFMutableDictionaryRef keyboard =
    myCreateDeviceMatchingDictionary(0x01, 6);
CFMutableDictionaryRef keypad =
    myCreateDeviceMatchingDictionary(0x01, 7);

CFMutableDictionaryRef matchesList[] = {
    keyboard,
    keypad,
};
CFArrayRef matches = CFArrayCreate(kCFAllocatorDefault,
        (const void **)matchesList, 2, NULL);
IOHIDManagerSetDeviceMatchingMultiple(hidManager, matches);

IOHIDManagerRegisterInputValueCallback(hidManager,
        myHIDKeyboardCallback, NULL);

IOHIDManagerScheduleWithRunLoop(hidManager, CFRunLoopGetMain(),
        kCFRunLoopDefaultMode);

IOHIDManagerOpen(hidManager, kIOHIDOptionsTypeNone);

CFMutableDictionaryRef myCreateDeviceMatchingDictionary(UInt32 usagePage,
        UInt32 usage) {
    CFMutableDictionaryRef ret = CFDictionaryCreateMutable(kCFAllocatorDefault,
            0, &kCFTypeDictionaryKeyCallBacks,
            &kCFTypeDictionaryValueCallBacks);
    if (!ret)
        return NULL;

    CFNumberRef pageNumberRef = CFNumberCreate(kCFAllocatorDefault,
            kCFNumberIntType, &usagePage );
    if (!pageNumberRef) {
        CFRelease(ret);
        return NULL;
    }

    CFDictionarySetValue(ret, CFSTR(kIOHIDDeviceUsagePageKey), pageNumberRef);
    CFRelease(pageNumberRef);

    CFNumberRef usageNumberRef = CFNumberCreate(kCFAllocatorDefault,
            kCFNumberIntType, &usage);
    if (!usageNumberRef) {
        CFRelease(ret);
        return NULL;
    }

    CFDictionarySetValue(ret, CFSTR(kIOHIDDeviceUsageKey), usageNumberRef);
    CFRelease(usageNumberRef);

    return ret;
}

void myHIDKeyboardCallback(void *context, IOReturn result, void *sender,
        IOHIDValueRef value) {
    IOHIDElementRef elem = IOHIDValueGetElement(value);
    if (IOHIDElementGetUsagePage(elem) != 0x07)
        return;
    uint32_t scancode = IOHIDElementGetUsage(elem);
    if (scancode < 4 || scancode > 231)
        return;
    long pressed = IOHIDValueGetIntegerValue(value);
    // ... Do something ...
}
其中myCreateDeviceMatchingDictionary类似于：

IOHIDManagerRef hidManager = IOHIDManagerCreate(kCFAllocatorDefault,
        kIOHIDOptionsTypeNone);

CFMutableDictionaryRef keyboard =
    myCreateDeviceMatchingDictionary(0x01, 6);
CFMutableDictionaryRef keypad =
    myCreateDeviceMatchingDictionary(0x01, 7);

CFMutableDictionaryRef matchesList[] = {
    keyboard,
    keypad,
};
CFArrayRef matches = CFArrayCreate(kCFAllocatorDefault,
        (const void **)matchesList, 2, NULL);
IOHIDManagerSetDeviceMatchingMultiple(hidManager, matches);

IOHIDManagerRegisterInputValueCallback(hidManager,
        myHIDKeyboardCallback, NULL);

IOHIDManagerScheduleWithRunLoop(hidManager, CFRunLoopGetMain(),
        kCFRunLoopDefaultMode);

IOHIDManagerOpen(hidManager, kIOHIDOptionsTypeNone);

CFMutableDictionaryRef myCreateDeviceMatchingDictionary(UInt32 usagePage,
        UInt32 usage) {
    CFMutableDictionaryRef ret = CFDictionaryCreateMutable(kCFAllocatorDefault,
            0, &kCFTypeDictionaryKeyCallBacks,
            &kCFTypeDictionaryValueCallBacks);
    if (!ret)
        return NULL;

    CFNumberRef pageNumberRef = CFNumberCreate(kCFAllocatorDefault,
            kCFNumberIntType, &usagePage );
    if (!pageNumberRef) {
        CFRelease(ret);
        return NULL;
    }

    CFDictionarySetValue(ret, CFSTR(kIOHIDDeviceUsagePageKey), pageNumberRef);
    CFRelease(pageNumberRef);

    CFNumberRef usageNumberRef = CFNumberCreate(kCFAllocatorDefault,
            kCFNumberIntType, &usage);
    if (!usageNumberRef) {
        CFRelease(ret);
        return NULL;
    }

    CFDictionarySetValue(ret, CFSTR(kIOHIDDeviceUsageKey), usageNumberRef);
    CFRelease(usageNumberRef);

    return ret;
}

void myHIDKeyboardCallback(void *context, IOReturn result, void *sender,
        IOHIDValueRef value) {
    IOHIDElementRef elem = IOHIDValueGetElement(value);
    if (IOHIDElementGetUsagePage(elem) != 0x07)
        return;
    uint32_t scancode = IOHIDElementGetUsage(elem);
    if (scancode < 4 || scancode > 231)
        return;
    long pressed = IOHIDValueGetIntegerValue(value);
    // ... Do something ...
}
myHIDKeyboardCallback类似于：

IOHIDManagerRef hidManager = IOHIDManagerCreate(kCFAllocatorDefault,
        kIOHIDOptionsTypeNone);

CFMutableDictionaryRef keyboard =
    myCreateDeviceMatchingDictionary(0x01, 6);
CFMutableDictionaryRef keypad =
    myCreateDeviceMatchingDictionary(0x01, 7);

CFMutableDictionaryRef matchesList[] = {
    keyboard,
    keypad,
};
CFArrayRef matches = CFArrayCreate(kCFAllocatorDefault,
        (const void **)matchesList, 2, NULL);
IOHIDManagerSetDeviceMatchingMultiple(hidManager, matches);

IOHIDManagerRegisterInputValueCallback(hidManager,
        myHIDKeyboardCallback, NULL);

IOHIDManagerScheduleWithRunLoop(hidManager, CFRunLoopGetMain(),
        kCFRunLoopDefaultMode);

IOHIDManagerOpen(hidManager, kIOHIDOptionsTypeNone);

CFMutableDictionaryRef myCreateDeviceMatchingDictionary(UInt32 usagePage,
        UInt32 usage) {
    CFMutableDictionaryRef ret = CFDictionaryCreateMutable(kCFAllocatorDefault,
            0, &kCFTypeDictionaryKeyCallBacks,
            &kCFTypeDictionaryValueCallBacks);
    if (!ret)
        return NULL;

    CFNumberRef pageNumberRef = CFNumberCreate(kCFAllocatorDefault,
            kCFNumberIntType, &usagePage );
    if (!pageNumberRef) {
        CFRelease(ret);
        return NULL;
    }

    CFDictionarySetValue(ret, CFSTR(kIOHIDDeviceUsagePageKey), pageNumberRef);
    CFRelease(pageNumberRef);

    CFNumberRef usageNumberRef = CFNumberCreate(kCFAllocatorDefault,
            kCFNumberIntType, &usage);
    if (!usageNumberRef) {
        CFRelease(ret);
        return NULL;
    }

    CFDictionarySetValue(ret, CFSTR(kIOHIDDeviceUsageKey), usageNumberRef);
    CFRelease(usageNumberRef);

    return ret;
}

void myHIDKeyboardCallback(void *context, IOReturn result, void *sender,
        IOHIDValueRef value) {
    IOHIDElementRef elem = IOHIDValueGetElement(value);
    if (IOHIDElementGetUsagePage(elem) != 0x07)
        return;
    uint32_t scancode = IOHIDElementGetUsage(elem);
    if (scancode < 4 || scancode > 231)
        return;
    long pressed = IOHIDValueGetIntegerValue(value);
    // ... Do something ...
}

void myHIDKeyboardCallback（void*上下文、IOReturn结果、void*发送方、，
IOHIDValueRef值）{
IOHIDElementRef elem=IOHIDValueGetElement（值）；
如果（IOHIDElementGetUsagePage（元素）！=0x07）
返回；
uint32\u t扫描代码=IOHIDElementGetUsage（elem）；
如果（扫描码<4 | |扫描码>231）
返回；
长按=IOHIDValueGetIntegerValue（值）；
//…做点什么。。。
}
请注意，每次按下或发布时，似乎会多次调用回调，但使用ID超出正常范围，这就是“如果（扫描代码<4 | |扫描代码>231）”的作用。

thx用于提供问题的答案

您可以使用IOHIDManagerSetInputValueMatching代替myHIDKeyboardCallback中检查scancode231的if语句

// before IOHIDManagerOpen
int usageMin = 4;
CFNumberRef minNumberRef = CFNumberCreate(kCFAllocatorDefault, kCFNumberIntType, &usageMin);
CFDictionarySetValue(inputValueFilter, CFSTR(kIOHIDElementUsageMinKey), minNumberRef);
CFRelease(minNumberRef);

int usageMax = 231;
CFNumberRef maxNumberRef = CFNumberCreate(kCFAllocatorDefault, kCFNumberIntType, &usageMax);
CFDictionarySetValue(inputValueFilter, CFSTR(kIOHIDElementUsageMaxKey), maxNumberRef);
CFRelease(maxNumberRef);

IOHIDManagerSetInputValueMatching(hidManager, inputValueFilter);
它比简单的if语句更简单，但最终的回调更干净。

很高兴知道。我想您也可以使用kIOHIDElementUsagePageKey将元素使用页面限制为0x07。但这有必要吗？键盘/小键盘设备是否生成过非0x07元素？我想，如果你有一个内置了触控板或操纵杆之类的外部键盘，这是可能的。我从来没有使用过这样的键盘（即带有操纵杆或类似的内置键盘），但我希望第二个设备和键盘的事件是分开的。但是我不能确定。关于如何使用IOHID API，你有什么好的来源吗？（我主要对读取鼠标/键盘输入感兴趣。）只需遵循苹果的文档，创建IOHIDManager和查找匹配的设备等都相当简单，但如何解析发送到回调的数据就不那么清楚了。听起来你对API有一定的经验，那么你知道有什么好的参考资料来解释这个问题吗？你在哪里找到了关于如何解析回调中的
值
的信息，以获得像扫描码这样的东西？你对此有什么（可读的）参考资料吗，或者你是怎么想出来的？ 
IOHIDManagerRef hidManager = IOHIDManagerCreate(kCFAllocatorDefault,
        kIOHIDOptionsTypeNone);
if (CFGetTypeID(hidManager) != IOHIDManagerGetTypeID())
    return 1;

CFMutableDictionaryRef capsLock =
    myCreateDeviceMatchingDictionary(0x07, 0x39);
CFMutableDictionaryRef lctrl =
    myCreateDeviceMatchingDictionary(0x07, 0xE0);
CFMutableDictionaryRef lshift =
    myCreateDeviceMatchingDictionary(0x07, 0xE1);
CFMutableDictionaryRef lalt =
    myCreateDeviceMatchingDictionary(0x07, 0xE2);
CFMutableDictionaryRef lsuper =
    myCreateDeviceMatchingDictionary(0x07, 0xE3);
CFMutableDictionaryRef rctrl =
    myCreateDeviceMatchingDictionary(0x07, 0xE4);
CFMutableDictionaryRef rshift =
    myCreateDeviceMatchingDictionary(0x07, 0xE5);
CFMutableDictionaryRef ralt =
    myCreateDeviceMatchingDictionary(0x07, 0xE6);
CFMutableDictionaryRef rsuper =
    myCreateDeviceMatchingDictionary(0x07, 0xE7);

CFMutableDictionaryRef matchesList[] = {
    capsLock,
    lctrl,
    lshift,
    lalt,
    lsuper,
    rctrl,
    rshift,
    ralt,
    rsuper
};
CFArrayRef matches = CFArrayCreate(kCFAllocatorDefault,
        (const void **)matchesList, 9, NULL);
IOHIDManagerSetDeviceMatchingMultiple(hidManager, matches);

IOHIDManagerRegisterInputValueCallback(hidManager,
        myHandleModifiersCallback, NULL);

IOHIDManagerScheduleWithRunLoop(hidManager, CFRunLoopGetMain(),
        kCFRunLoopDefaultMode);

IOHIDManagerOpen(hidManager, kIOHIDOptionsTypeNone);