Saya tidak begitu mengerti mengapa UIPickerViewterjadi di dalam a UIActionSheet. Ini tampaknya menjadi solusi yang berantakan dan meretas, yang dapat rusak dalam rilis iOS di masa mendatang. (Saya pernah mengalami hal-hal seperti jeda ini di aplikasi sebelumnya, di mana UIPickerViewtidak ditampilkan pada ketukan pertama dan harus ditarik kembali - kebiasaan aneh dengan UIActionSheet).
Apa yang saya lakukan hanyalah menerapkan UIPickerViewdan kemudian menambahkannya sebagai subview ke tampilan saya, dan menganimasikannya bergerak ke atas seolah-olah itu disajikan seperti lembar tindakan.
/// Add the PickerView as a private variable
@interface EMYourClassName ()
@property (nonatomic, strong) UIPickerView *picker;
@property (nonatomic, strong) UIButton *backgroundTapButton;
@end
///
/// This is your action which will present the picker view
///
- (IBAction)showPickerView:(id)sender {
// Uses the default UIPickerView frame.
self.picker = [[UIPickerView alloc] initWithFrame:CGRectZero];
// Place the Pickerview off the bottom of the screen, in the middle set the datasource delegate and indicator
_picker.center = CGPointMake([[UIScreen mainScreen] bounds].size.width / 2.0, [[UIScreen mainScreen] bounds].size.height + _picker.frame.size.height);
_picker.dataSource = self;
_picker.delegate = self;
_picker.showsSelectionIndicator = YES;
// Create the toolbar and place it at -44, so it rests "above" the pickerview.
// Borrowed from @Spark, thanks!
UIToolbar *pickerDateToolbar = [[UIToolbar alloc] initWithFrame:CGRectMake(0, -44, 320, 44)];
pickerDateToolbar.barStyle = UIBarStyleBlackTranslucent;
[pickerDateToolbar sizeToFit];
NSMutableArray *barItems = [[NSMutableArray alloc] init];
UIBarButtonItem *flexSpace = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:self action:nil];
[barItems addObject:flexSpace];
// The action can whatever you want, but it should dimiss the picker.
UIBarButtonItem *doneBtn = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(backgroundTapped:)];
[barItems addObject:doneBtn];
[pickerDateToolbar setItems:barItems animated:YES];
[_picker addSubview:pickerDateToolbar];
// If you have a UITabBarController, you should add the picker as a subview of it
// so it appears to go over the tabbar, not under it. Otherwise you can add it to
// self.view
[self.tabBarController.view addSubview:_picker];
// Animate it moving up
[UIView animateWithDuration:.3 animations:^{
[_picker setCenter:CGPointMake(160, [[UIScreen mainScreen] bounds].size.height - 148)]; //148 seems to put it in place just right.
} completion:^(BOOL finished) {
// When done, place an invisible button on the view behind the picker, so if the
// user "taps to dismiss" the picker, it will go away. Good user experience!
self.backgroundTapButton = [UIButton buttonWithType:UIButtonTypeCustom];
_backgroundTapButton.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);
[_backgroundTapButton addTarget:self action:@selector(backgroundTapped:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:_backgroundTapButton];
}];
}
// And lastly, the method to hide the picker. You should handle the picker changing
// in a method with UIControlEventValueChanged on the pickerview.
- (void)backgroundTapped:(id)sender {
[UIView animateWithDuration:.3 animations:^{
_picker.center = CGPointMake(160, [[UIScreen mainScreen] bounds].size.height + _picker.frame.size.height);
} completion:^(BOOL finished) {
[_picker removeFromSuperview];
self.picker = nil;
[self.backgroundTapButton removeFromSuperview];
self.backgroundTapButton = nil;
}];
}
