在运行时将UIDatePicker添加到UIView的问题

Question

我想在用户单击按钮时将UIDatePicker添加到UIView。我有一个动画设置，从底部向上滑动UIView。如果我将UIDatePicker添加到ViewControllers视图，则DatePicker将正确显示。但是，如果我将DatePicker添加到UIView，那么日期选取器根本不显示。

- (IBAction)setTimeButtonPressed:(UIButton *)sender 
{ 
    // Creates Frame Rects for views and controls 
    CGRect datePickerViewOutFrame = CGRectMake(0, 336, self.view.frame.size.width, 228); 
    CGRect datePickerOutFrame = CGRectMake(0, 336, self.view.frame.size.width, 162); 

    // Create View that will slide out 
    UIView *datePickerView = [[UIView alloc] initWithFrame:CGRectMake(0, self.view.frame.size.height, self.view.frame.size.width, 0)]; 
    datePickerView.backgroundColor = [UIColor flatCloudsColor]; 

    // Setup DatePicker 
    UIDatePicker *datePicker = [[UIDatePicker alloc] initWithFrame:CGRectMake(0, self.view.frame.size.height, self.view.frame.size.width, 0)]; 
    datePicker.datePickerMode = UIDatePickerModeTime; 
    datePicker.date = [NSDate date]; 
    datePicker.hidden = NO; 

    [self.view addSubview:datePickerView]; 
    [datePickerView addSubview:datePicker]; /* DOES NOT WORK*/ 

    self.datePickerView.clipsToBounds = YES; 

    // Animate the views sliding out from the bottom 
    [UIView animateWithDuration:0.5 
          delay:0 
         options:UIViewAnimationOptionCurveLinear 
        animations:^{ 
         datePicker.frame = datePickerOutFrame; 
         datePickerView.frame = datePickerViewOutFrame; 

        } 
        completion:^(BOOL finished){ 
         // Might need later 
        }]; 
} 

但是，如果我改变，我添加日期选择器的线路，它的工作原理，但然后我不能把它夹到datePickerView的边界。

[self.view addSubview:datePickerView]; 
[self.view addSubview:datePicker]; /* Works but can't clip DatePicker */ 

我在做什么错？

Answer 1

UIDatePickerView框架需要相对于其父视图。因此，如果您想将其添加到您的datePickerView，那么UIDatePicker的帧应该具有0,0的原点，而不是基于视图控制器视图的高度。

UIDatePicker *datePicker = [[UIDatePicker alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, 0)];