目标C实现具有“完成”的UIPickerView。按键 [英] Objective C implementing a UIPickerView with a "Done" button

问题描述

我正在尝试在UIPickerView中实现完成按钮，类似于 link

I am trying to implement a "Done" button in a UIPickerView Similar to the one under this link

我看了课程参考但我找不到它

I looked in the class reference but I couldn t find it

谢谢

推荐答案

我添加了一个带有UIBarButtonItem的UIToolbar，用于我的xib中的'done'按钮，框架设置为最初不是可见（y值等于父视图的高度）。

I added a UIToolbar with a UIBarButtonItem for the 'done' button in my xib with the frame set so that it's not initially visible (y value equal to the height of the parent view).

每次用户访问选择器时，我都改变了UIDatePicker的框架（y值）和UIToolbar带有一个动画，以便它与屏幕底部的拾取器一起向上滑动，类似于键盘。

Every time the user access the picker, I changed the frame (the y value) of the UIDatePicker and the UIToolbar with an animation so that it slides up along with the picker from the bottom of the screen similar to the keyboard.

查看下面的代码。

- (IBAction)showPicker
{
    if(pickerVisible == NO)
    {
        // create the picker and add it to the view
        if(self.datePicker == nil) self.datePicker = [[[UIDatePicker alloc] initWithFrame:CGRectMake(0, 460, 320, 216)] autorelease];
        [self.datePicker setMaximumDate:[NSDate date]];
        [self.datePicker setDatePickerMode:UIDatePickerModeDate];
        [self.datePicker setHidden:NO];
        [self.view addSubview:datePicker];

        // the UIToolbar is referenced 'using self.datePickerToolbar'
        [UIView beginAnimations:@"showDatepicker" context:nil];
        // animate for 0.3 secs.
        [UIView setAnimationDuration:0.3];

        CGRect datepickerToolbarFrame = self.datePickerToolbar.frame;
        datepickerToolbarFrame.origin.y -= (self.datePicker.frame.size.height + self.datePickerToolbar.frame.size.height);
        self.datePickerToolbar.frame = datepickerToolbarFrame;

        CGRect datepickerFrame = self.datePicker.frame;
        datepickerFrame.origin.y -= (self.datePicker.frame.size.height + self.datePickerToolbar.frame.size.height);
        self.datePicker.frame = datepickerFrame;

        [UIView commitAnimations];
        pickerVisible = YES;
    }
}

- (IBAction)done
{
    if(pickerVisible == YES)
    {
        [UIView beginAnimations:@"hideDatepicker" context:nil];
        [UIView setAnimationDuration:0.3];

        CGRect datepickerToolbarFrame = self.datePickerToolbar.frame;
        datepickerToolbarFrame.origin.y += (self.datePicker.frame.size.height + self.datePickerToolbar.frame.size.height);
        self.datePickerToolbar.frame = datepickerToolbarFrame;

        CGRect datepickerFrame = self.datePicker.frame;
        datepickerFrame.origin.y += (self.datePicker.frame.size.height + self.datePickerToolbar.frame.size.height);
        self.datePicker.frame = datepickerFrame;
        [UIView commitAnimations];

        // remove the picker after the animation is finished
        [self.datePicker performSelector:@selector(removeFromSuperview) withObject:nil afterDelay:0.3];
    }
}

这篇关于目标C实现具有“完成”的UIPickerView。按键的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！