iOS KVO开发-防止remove删除崩溃（Swift/Obj

ObjC：
删除前使用observerKeyPath判断是否能删除

// 进行检索获取Key
- (BOOL)observerKeyPath:(NSObject*)object :(NSString *)key
{
    //判断keyPath有或者无来实现防止多次重复添加和删除KVO监听
    id info = object.observationInfo;
    NSArray *array = [info valueForKey:@"_observances"];
    for (id objc in array) {
        id properties = [objc valueForKeyPath:@"_property"];
        NSString *keyPath = [properties valueForKeyPath:@"_keyPath"];
        if ([key isEqualToString:keyPath]) {
            return YES;
        }
    }
    return NO;
}

Swift：
使用objAddObserver添加观察者、使用objRemoveObserver删除

var objKeyArr:Array<(Object:NSObject, Key:String)> = []//储存绑定KVO的数组
func objAddObserver(_ obj:NSObject,_ key:String) {
    obj.addObserver(self, forKeyPath: key, options: .new, context: nil)
    let aTuple = (Object:obj, Key:key)//使用元组obj-key对应
    objKeyArr.append(aTuple)//储存绑定的KVO
}
func objRemoveObserver(_ obj:NSObject,_ key:String) {
    guard let remObjIndex = objKeyArr.firstIndex(where: { $0.Object==obj && $0.Key==key}) else { return }//查找obj和key是否已绑定
    obj.removeObserver(self, forKeyPath: key)
    objKeyArr.remove(at: remObjIndex)
}