我正在尝试在我的应用程序中获取触摸事件。所以我使用IOHIDFamily回调来获取事件。我的代码是这样的:
I'm trying to get touch events in my application. So I used the IOHIDFamily callback to get the events. My code is like this:
void handle_event(void* target, void* refcon, IOHIDServiceRef service, IOHIDEventRef event) { printf("Received event of type %2d from service %p.\n", IOHIDEventGetType(event), service); } - (void)viewDidLoad { [super viewDidLoad]; void *ioHIDEventSystem = IOHIDEventSystemClientCreate(kCFAllocatorDefault); IOHIDEventSystemClientScheduleWithRunLoop(system, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode); IOHIDEventSystemClientRegisterEventCallback(system, handle_event, NULL, NULL); CFRunLoopRun(); }执行时出错:
IOHIDEventSystemClientScheduleWithRunLoop(system,CFRunLoopGetCurrent(),kCFRunLoopDefaultMode);
IOHIDEventSystemClientScheduleWithRunLoop(system, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);
IOKit`IOHIDEventSystemClientScheduleWithRunLoop: ... 0x32f8fd14:cmp.w r10,#0 0x32f8fd18:strd r10,r11,[r4,#116]< --- EXC_BAD_ACCESS(代码= EXC_ARM_DA_ALIGN) 0x32f8fd1c:beq 0x32f8fdac; IOHIDEventSystemClientScheduleWithRunLoop + 168 0x32f8fd1e:ldr r1,[r4,#96] 0x32f8fd20:cbz r1,0x32f8fd2a; IOHIDEventSystemClientScheduleWithRunLoop + 38 0x32f8fd22:mov r0,r10 ...
IOKit`IOHIDEventSystemClientScheduleWithRunLoop: ... 0x32f8fd14: cmp.w r10, #0 0x32f8fd18: strd r10, r11, [r4, #116] <---EXC_BAD_ACCESS(code=EXC_ARM_DA_ALIGN) 0x32f8fd1c: beq 0x32f8fdac ; IOHIDEventSystemClientScheduleWithRunLoop + 168 0x32f8fd1e: ldr r1, [r4, #96] 0x32f8fd20: cbz r1, 0x32f8fd2a ; IOHIDEventSystemClientScheduleWithRunLoop + 38 0x32f8fd22: mov r0, r10 ...
我以错误的方式使用IOHIDFamily?
Did I use IOHIDFamily in the wrong way?
推荐答案我发现代码中至少有几个问题:
There's at least a couple problems I see in the code posted:
首先,您正在致电
CFRunLoopRun();$ b
在 viewDidLoad 方法中在main / UI线程上调用。我认为没有理由,所以只需删除该行。我通常希望看到那个调用,如果你有一个方法,你在后台线程上运行,你需要启动后台运行循环。或者,如果您直接在 main()中注册回调,请回答。
in the viewDidLoad method, which is going to be called on the main/UI thread. I see no reason for that, so just remove that line. I'd normally expect to see that call if you had a method that you were running on a background thread, and you needed to start a background run loop. Or, if you were registering for callbacks directly in main(), as in this answer.
然后,你有这个:
void *ioHIDEventSystem = IOHIDEventSystemClientCreate(kCFAllocatorDefault); IOHIDEventSystemClientScheduleWithRunLoop(system, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);我猜第二行应该是
IOHIDEventSystemClientScheduleWithRunLoop(ioHIDEventSystem, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);我不知道系统是什么变量实际上是指,但它看起来不正确。
I don't know what the system variable actually refers to, but it doesn't look right.
参加看看最近的答案,因为它似乎正确使用 IOKit 。
Take a look at this recent answer, as it seems to use IOKit correctly.
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IOHIDEventSystemClientScheduleWithRunLoop与EXC
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