我想通了:
+ (BOOL)isForceTouchCapable
{
if (![[self class] isAtLeastElCapitan])
return NO;
io_iterator_t iterator;
//get default HIDDevice dictionary
CFMutableDictionaryRef mDict = IOServiceMatching(kIOHIDDeviceKey);
//add manufacturer "Apple Inc." to dict
CFDictionaryAddValue(mDict, CFSTR(kIOHIDManufacturerKey), CFSTR("Apple Inc."));
//get matching services, depending on dict
IOReturn ioReturnValue = IOServiceGetMatchingServices(kIOMasterPortDefault, mDict, &iterator);
BOOL result = YES;
if (ioReturnValue != kIOReturnSuccess)
NSLog(@"error getting matching services for force touch devices");
else
{
//recursively go through each device found and its children and grandchildren, etc.
result = [[self class] _containsForceTouchDevice:iterator];
IOObjectRelease(iterator);
}
return result;
}
+ (BOOL)_containsForceTouchDevice:(io_iterator_t)iterator
{
io_object_t object = 0;
BOOL success = NO;
while ((object = IOIteratorNext(iterator)))
{
CFMutableDictionaryRef result = NULL;
kern_return_t state = IORegistryEntryCreateCFProperties(object, &result, kCFAllocatorDefault, 0);
if (state == KERN_SUCCESS && result != NULL)
{
if (CFDictionaryContainsKey(result, CFSTR("DefaultMultitouchProperties")))
{
CFDictionaryRef dict = CFDictionaryGetValue(result, CFSTR("DefaultMultitouchProperties"));
CFTypeRef val = NULL;
if (CFDictionaryGetValueIfPresent(dict, CFSTR("ForceSupported"), &val))
{
Boolean aBool = CFBooleanGetValue(val);
if (aBool) //supported
success = YES;
}
}
}
if (result != NULL)
CFRelease(result);
if (success)
{
IOObjectRelease(object);
break;
} else
{
io_iterator_t childIterator = 0;
kern_return_t err = IORegistryEntryGetChildIterator(object, kIOServicePlane, &childIterator);
if (!err)
{
success = [[self class] _containsForceTouchDevice:childIterator];
IOObjectRelease(childIterator);
} else
success = NO;
IOObjectRelease(object);
}
}
return success;
}
只需撥打+(BOOL)isForceTouchCapable,如果一個部隊觸摸設備可用,就返回YES(一個魔術觸控板2或內置有效觸摸,觸控板)或者如果沒有則爲否。
對於那些對此感興趣的人,我寫了一個關於它的示例項目on my blog。
它是swift還是obj-c? –
我忘了 - objective-c –