按下按钮后如何动画显示 UIPickerView？

Question

我想在按下按钮后为我的 UIPickerView 设置动画。我已经将我的 UIPickerView 编码为隐藏在 viewDidLoad 上，并且在按下按钮后不隐藏，但它不像 ModalViewController 默认的动画那样动画。我只想让我的 UIPickerView 像 ModalViewController 默认动画一样进行动画处理。

我已经在网站和网络上进行了研究，但我似乎无法正确完成。

这是我的代码：

#pragma mark - Picker View 

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
    return 1;
}

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
    return 4;
}

- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
    timersArray = [[NSMutableArray alloc] init];
    [timersArray addObject:@"No timer"];
    [timersArray addObject:@"15 seconds"];
    [timersArray addObject:@"30 seconds"];
    [timersArray addObject:@"60 seconds"];

    return [timersArray objectAtIndex:row];
}

- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
    if ([[timersArray objectAtIndex:row] isEqual:@"No timer"])
    {
        timerIndication.text = @"No timer selected";
        timersPickerView.hidden = YES;
        // Animation code to dismiss picker should go here
    }
    else if ([[timersArray objectAtIndex:row] isEqual:@"15 seconds"])
    {
        timerIndication.text = @"15 seconds selected";
        timersPickerView.hidden = YES;
        // Animation code to dismiss picker should go here
    }
    else if ([[timersArray objectAtIndex:row] isEqual:@"30 seconds"])
    {
        timerIndication.text = @"30 seconds selected";
        timersPickerView.hidden = YES;
        // Animation code to dismiss picker should go here
    }
    else if ([[timersArray objectAtIndex:row] isEqual:@"60 seconds"])
    {
        timerIndication.text = @"60 seconds selected";
        timersPickerView.hidden = YES;
        // Animation code to dismiss picker should go here
    }
}

#pragma mark - Delay method

// This is where Send button should be enabled
- (IBAction)selectTimer
{
    timersPickerView.hidden = NO;
    // Animation code to present picker view should go here
}

Answer 1

您可以使用以下代码在按下按钮后为选取器视图设置动画：

-(IBAction)button:(id)sender
{

   [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:0.6];
    CGAffineTransform transfrom = CGAffineTransformMakeTranslation(0, 200);
    PickerView.transform = transfrom;
    PickerView.alpha = PickerView.alpha * (-1) + 1;
    [UIView commitAnimations];

}

不要忘记将以下代码添加到您的 viewDidLoad 方法中

PickerView.alpha = 0;    
[self.view addSubview:PickerView];

它的作用是使选择器视图在第一次单击时从屏幕顶部下降并让选择器视图消失，您只需再次单击按钮即可。从下一次单击中，选择器视图会出现并消失。 .希望它有所帮助和工作:)

Answer 2

你可以创建一个viewcontroller，然后在controller里面添加UIPickerView，然后使用：

[self presentModalViewController:viewControllerWithPickerView Animation:YES];

或者您可以添加不隐藏但 y 值大于屏幕的 UIPickerView，例如 480.0 或更大，然后使用 UIView 动画将 UIPickerView 从该位置移动到屏幕上可见的位置，这将模拟 ModalViewController 动画.

Answer 3

您可以使用下面的函数来执行选择器视图的动画。

-(void)hideShowPickerView {

if (!isPickerDisplay) {
    [UIView animateWithDuration:0.25 animations:^{
        CGRect temp = self.categoryPicker.frame;
        temp.origin.y = self.view.frame.size.height - self.categoryPicker.frame.size.height;
        self.categoryPicker.frame = temp;
    } completion:^(BOOL finished) {
        NSLog(@"picker displayed");
        isPickerDisplay = YES;
    }];
}else {
    [UIView animateWithDuration:0.25 animations:^{
        CGRect temp = self.categoryPicker.frame;
        temp.origin.y = self.view.frame.size.height;
        self.categoryPicker.frame = temp;
    } completion:^(BOOL finished) {
        NSLog(@"picker hide");
        isPickerDisplay = NO;
    }];
}

}

将 isPickerDisplay 定义为 BOOL 并将其初始化为 ViewDidLoad，如下所示 -

isPickerDisplay = YES;
[self hideShowPickerView];

这将管理 UIPickerView 的隐藏和显示功能。

Answer 4

Swift 3 解决方案

我同意@EshwarChaitanya，alpha 属性是可动画的，这是一个合适的用途。

override func viewDidLoad() {
    super.viewDidLoad()
    
    timersPickerView.alpha = 0
}

@IBAction func selectTimer() {
    UIView.animate(withDuration: 0.3, animations: {
        self.timersPickerView.alpha = 1
    })
}

我不确定你想如何隐藏它，所以我会留给你。

Answer 5

当您按下按钮时，执行操作 [self.view addSubVuew:yourPickerView]; .没用吗？

Answer 6

Swift 5：上滑动画

1- 将高度设置为 216（PickerView 标准）。

2- 设置引导到安全区域的尾随。

3- 将底部设置为“SuperViewBottom”为 -216。

4- 将第 3 行的 IBOutlet 作为 NSLayoutConstraint 可选。

然后：

import UIKit

class ViewController: UIViewController {

 override func viewDidLoad() {

 super.viewDidLoad()

 bottom.constant = -216

}

@IBOutlet weak var bottom: NSLayoutConstraint!

-(IBAction)button:(id)sender
{
   UIView.animate(withDuration: 0.2, delay: 0.0, options: .curveEaseIn, animations:
        {
            self.bottom.constant = 0
        self.view.layoutIfNeeded()
        }) { (AnimationComplete ) in }
}

 override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
       

        UIView.animate(withDuration: 0.2, delay: 0.0, options: .curveEaseIn, animations:
        {
            self.bottom.constant = -216
        self.view.layoutIfNeeded()
        }) { (AnimationComplete ) in }
   
    }


}

它应该像 Apple 标准动画一样工作。

祝你好运?