点击空白收起键盘的两种方式

• 核心代码 [self.view endEditing:YES];

• 使用 vc 的 touchesBegan 事件

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    [self.view endEditing:YES];
}

• 使用 UITapGestureRecognizer 信号订阅

   @weakify(self);
    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] init];
    tap.numberOfTapsRequired = 1;
    tap.numberOfTouchesRequired = 1;
    [[tap rac_gestureSignal] subscribeNext:^(__kindof UIGestureRecognizer * _Nullable x) {
        @strongify(self);
        [self.view.window endEditing:YES];
    }];
    [self.view addGestureRecognizer:tap];