Hide Show UIPicker on button click

Question

I want to do something like the keyboard show/hide so I want to set up picker as a first responder. Is this possible. If not how can i show/hide UIPicker in a view by a button click. On other topic how can i format the DatePicker output, now i get "2011-12-8 23:00 000000"

Answer 1

You could have your UIPicker below your sceen (say, y = 480 for iPhone), and then when you tap your button move it to 480 - picker.frame.size.height so that it shows right above the bottom of your screen.

You can achieve the animated effect by using UIView animations as:

// Pre OS4 way

[UIView beginAnimations:@"animName" context:NULL];
[UIView setAnimationDuration:0.2];

CGRect f = picker.frame;

if (showingPicker) {
    f.origin.y = 480;
}
else {
    f.origin.y = 480 - picker.frame.size.height;
}

picker.frame = f;

[UIView commitAnimations];

// Post OS4 way - Block based

[UIView animateWithDuration:0.2 animations:^{

    if (showingPicker) {
        f.origin.y = 480;
    }
    else {
        f.origin.y = 480 - picker.frame.size.height;
    }

    picker.frame = f;

}

And for the DatePicker output you can use an NSDateFormatter . You can use predefined date and time styles or use setDateFormat:(NSString *)format to specify the format yourself.

After that all you do is call your [formatter stringFromDate:datePicker.date];

Answer 2

您可以在此处找到有关如何使用UIDataPicker的完整源代码。