ios - ReactiveCocoa : Handling Multiple Unbalanced Keyboard Notifications

Question

我正在使用 Reactive Cocoa 构建一个示例身份验证 View Controller 。我知道如何以 react 方式设置和接收来自键盘的通知。但是，我收到不平衡的 UP 和 DOWN 通知。因此，我必须设置一个 BOOL 变量来查看键盘之前是否已抬起但未放下。有没有办法 react 地做到这一点？完整的项目是here .

- (void)configureKeyboardAnimations {
CGFloat duration = 0.9, damping = 0.8;
@weakify(self);
[[[NSNotificationCenter.defaultCenter rac_addObserverForName:UIKeyboardWillShowNotification
                                                      object:nil]
  takeUntil:self.rac_willDeallocSignal] subscribeNext:^(NSNotification *notification) {
    @strongify(self);
    if (!self.tableViewOffset) {
        CGRect keyboardRect = [notification.userInfo[UIKeyboardFrameBeginUserInfoKey] CGRectValue];
        [UIView animateWithDuration:duration delay:0 usingSpringWithDamping:damping
              initialSpringVelocity:0 options:UIViewAnimationOptionAllowAnimatedContent
                         animations:^{
                             self.tableView.frame = CGRectOffset(self.tableView.frame, 0,
                                                                 -CGRectGetHeight(keyboardRect));
                         } completion:^(BOOL finished) {}];
        self.tableViewOffset = YES; //I need this set immediately not at completion. 
    }
}];

[[[NSNotificationCenter.defaultCenter rac_addObserverForName:UIKeyboardWillHideNotification
                                                      object:nil]
  takeUntil:self.rac_willDeallocSignal] subscribeNext:^(NSNotification *notification) {
    @strongify(self);
    CGRect keyboardRect = [notification.userInfo[UIKeyboardFrameBeginUserInfoKey] CGRectValue];
    [UIView animateWithDuration:duration delay:0 usingSpringWithDamping:damping
          initialSpringVelocity:0 options:UIViewAnimationOptionAllowAnimatedContent
                     animations:^{
                         self.tableView.frame = CGRectOffset(self.tableView.frame, 0,
                                                             CGRectGetHeight(keyboardRect));
                     } completion:^(BOOL finished) {}];
    self.tableViewOffset = NO; //I need this set immediately not at completion. 
}];

Answer 1

我想我已经为您找到了解决方案。可能不是最简单的，但它会起作用，我觉得这是解决问题的“ReactiveCocoa”方法。

RACSignal *keyboardShowSignal = [[NSNotificationCenter.defaultCenter rac_addObserverForName:UIKeyboardWillShowNotification object:nil] takeUntil:self.rac_willDeallocSignal];

RACSignal *keyboardHideSignal = [[NSNotificationCenter.defaultCenter rac_addObserverForName:UIKeyboardWillHideNotification object:nil] takeUntil:self.rac_willDeallocSignal];

RACSignal *latestNotification = [RACSignal merge:@[keyboardShowSignal, keyboardHideSignal]];
[[[latestNotification map:^id(NSNotification *notification) {
    return notification.userInfo[UIKeyboardFrameBeginUserInfoKey];
}] distinctUntilChanged] subscribeNext:^(NSNumber *rectNumber) {
    // Animate things here with [rectNumber CGRectValue]
}];

RAC(self, tableViewOffset) = [[[latestNotification map:^id(NSNotification *notification) {
    return @([notification.name isEqualToString:UIKeyboardWillShowNotification]);
}] distinctUntilChanged] startWith:@(NO)];

完整的项目是here .