ios获取用户事件

void handle_event(void* target, void* refcon, IOHIDEventQueueRef queue, IOHIDEventRef event) {
    if (IOHIDEventGetType(event) == kIOHIDEventTypeDigitizer) {
       void* children = IOHIDEventGetChildren(event);
        int count = CFArrayGetCount(children);
        for (int i = 0; i < count; i++) {
            void* item = CFArrayGetValueAtIndex(children, i);
             mainX = IOHIDEventGetFloatValue(item,kIOHIDEventFieldDigitizerX) * [[UIScreen mainScreen] bounds].size.width;
            mainY = IOHIDEventGetFloatValue(item,kIOHIDEventFieldDigitizerY) * [[UIScreen mainScreen] bounds].size.height;
            mainType = IOHIDEventGetFloatValue(item,kIOHIDEventFieldDigitizerType);
            mainIndex = IOHIDEventGetFloatValue(item,kIOHIDEventFieldDigitizerIndex);
      
    }
}

IOHIDEventSystemClientRef client = IOHIDEventSystemClientCreate(kCFAllocatorDefault);
IOHIDEventSystemClientScheduleWithRunLoop(client, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);
IOHIDEventSystemClientRegisterEventCallback(client, handle_event, 0, 0);