Objective C - 离开时 CBCentralManager NSInternalInconsistencyException ViewController

Question

我是按照 How to get the status of bluetooth (ON/OFF) in iphone programatically 的代码来获取蓝牙状态的。

但是当我通过后退导航按钮弹出 viewController 时，应用程序崩溃并出现以下错误。

[CoreBluetooth] XPC connection invalid

*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'An instance 0x170261c80 of class CBCentralManager was deallocated while key value observers were still registered with it. Current observation info: ( Context: 0x1aa9c3710, Property: 0x170056b90> Context: 0x1aa9c3710, Property: 0x170056b00> Context: 0x1aa9c3710, Property: 0x170056b90> Context: 0x1aa9c3710, Property: 0x170056b00> )'

我尝试在调用viewWillDisappear时移除上述观察者，但仍然报错

[self.bluetoothManager removeObserver:self forKeyPath:@"state"];
[self.bluetoothManager removeObserver:self forKeyPath:@"delegate"];

我试过了

self.bluetoothManager.delegate = nil;

和

self.bluetoothManager = nil;

遗憾的是他们都没有作品。

请给予帮助。

更新：

我想在调用 - (void)detectBluetooth 时显示系统弹出警报，而蓝牙未打开。所以我添加

[self.bluetoothManager init];

in - (void)detectBluetooth.

我发现犯了这个错误。

但我想不出另一种方法来显示默认弹出窗口（带有设置按钮）。

Answer 1

我找到了发生此错误的根本原因。

我对蓝牙管理器进行了多次初始化，所以它自己分配了多个观察者。

根据我的目的，在蓝牙未打开时显示系统警报弹出窗口。由于 init 会弹出警报，我需要先将 nil 设置为蓝牙管理器，然后再设置 init。这没有错误。

这是我的最终代码：

if(!self.bluetoothManager)
{
    // Put on main queue so we can call UIAlertView from delegate callbacks.
    self.bluetoothManager = [[CBCentralManager alloc] initWithDelegate:self queue:dispatch_get_main_queue()];
} else{
    if (self.bluetoothManager.state != CBManagerStatePoweredOn) {
        self.bluetoothManager = nil;
        self.bluetoothManager = [[CBCentralManager alloc] initWithDelegate:self queue:dispatch_get_main_queue()];
    }
}
[self centralManagerDidUpdateState:self.bluetoothManager];


- (void)centralManagerDidUpdateState:(CBCentralManager *)central
{
    switch(self.bluetoothManager.state)
    {
        case CBCentralManagerStatePoweredOn: [self pushViewController]; break;
        case CBCentralManagerStateResetting:
        case CBCentralManagerStateUnsupported:
        case CBCentralManagerStateUnauthorized:
        case CBCentralManagerStatePoweredOff:
        default: break;
    }
}

Objective C - 离开时 CBCentralManager NSInternalInconsistencyException ViewController

Objective C - CBCentralManager NSInternalInconsistencyException when leaving ViewController

bluetooth

objective-c

ios

core-bluetooth