Objective C 使用“完成”按钮实现 UIPickerView

Posted 2023-02-24

【中文标题】Objective C 使用“完成”按钮实现 UIPickerView

【英文标题】：Objective C implementing a UIPickerView with a "Done" button

【发布时间】：2012-05-22 14:56:40

【问题描述】：

我正在尝试在 UIPickerView 中实现一个“完成”按钮，类似于 link 下的按钮

我查看了类参考，但找不到它

谢谢

【参考方案1】：

最简单的方法是在 Interface Builder 中对其进行建模。它是一个UIView，包含一个UIToolbar 和一个UIPickerView。

然后为UIView 创建一个插座并连接它。

如果您有UITextField，您可以将您的自定义视图分配给它的inputView 属性。

[self.textField setInputView:self.customPicker];

或者，您可以将选择器添加到主视图...

- (void)viewDidLoad

    [super viewDidLoad];

    self.customPicker.frame = CGRectMake(0, CGRectGetMaxY(self.view.frame), CGRectGetWidth(self.customPicker.frame), CGRectGetHeight(self.customPicker.frame));
    [self.view addSubview:self.customPicker];

...然后使用此方法显示或隐藏选择器。

- (void)setPickerHidden:(BOOL)hidden

    CGAffineTransform transform = hidden ? CGAffineTransformIdentity : CGAffineTransformMakeTranslation(0, -CGRectGetHeight(self.customPicker.frame));

    [UIView animateWithDuration:0.3 animations:^
        self.customPicker.transform = transform;
    ];

【讨论】：

你的 XCode 使用什么主题？

@nemesis 我想是这个：github.com/chriskempson/tomorrow-theme/tree/master/Xcode%204

【参考方案2】：

我在我的 xib 中为“完成”按钮添加了一个带有 UIBarButtonItem 的 UIToolbar，并设置了框架，使其最初不可见（y 值等于父视图的高度）。

每次用户访问选择器时，我都会用动画更改 UIDatePicker 和 UIToolbar 的框架（y 值），使其与选择器一起从屏幕底部向上滑动，类似于键盘。

在下面查看我的代码。

- (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];
    

【讨论】：

你应该看看@Paul-Hunter's answer for create the xib components。

【参考方案3】：

我创建了一个自定义类，它支持多方向：

日期时间选择器.h

    @interface DateTimePicker : UIView 


@property (nonatomic, assign, readonly) UIDatePicker *picker;

- (void) setMode: (UIDatePickerMode) mode;
- (void) addTargetForDoneButton: (id) target action: (SEL) action;

@end

日期时间选择器.m

#define MyDateTimePickerToolbarHeight 40

@interface DateTimePicker()

@property (nonatomic, assign, readwrite) UIDatePicker *picker;

@property (nonatomic, assign) id doneTarget;
@property (nonatomic, assign) SEL doneSelector;

- (void) donePressed;

@end


@implementation DateTimePicker

@synthesize picker = _picker;

@synthesize doneTarget = _doneTarget;
@synthesize doneSelector = _doneSelector;

- (id) initWithFrame: (CGRect) frame 
    if ((self = [super initWithFrame: frame])) 
        self.backgroundColor = [UIColor clearColor];

        UIDatePicker *picker = [[UIDatePicker alloc] initWithFrame: CGRectMake(0, MyDateTimePickerToolbarHeight, frame.size.width, frame.size.height - MyDateTimePickerToolbarHeight)];
        [self addSubview: picker];

        UIToolbar *toolbar = [[UIToolbar alloc] initWithFrame: CGRectMake(0, 0, frame.size.width, MyDateTimePickerToolbarHeight)];
        toolbar.barStyle = UIBarStyleBlackOpaque;
        toolbar.autoresizingMask = UIViewAutoresizingFlexibleWidth;

        UIBarButtonItem *doneButton = [[UIBarButtonItem alloc] initWithTitle: @"Done" style: UIBarButtonItemStyleBordered target: self action: @selector(donePressed)];
        UIBarButtonItem* flexibleSpace = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil];
        toolbar.items = [NSArray arrayWithObjects:flexibleSpace, doneButton, nil];

        [self addSubview: toolbar];

        self.picker = picker;
        picker.autoresizingMask = UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight|UIViewAutoresizingFlexibleTopMargin|UIViewAutoresizingFlexibleBottomMargin;

        self.autoresizesSubviews = YES;
        self.autoresizingMask = UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight|UIViewAutoresizingFlexibleTopMargin|UIViewAutoresizingFlexibleBottomMargin;
    
    return self;


- (void) setMode: (UIDatePickerMode) mode 
    self.picker.datePickerMode = mode;


- (void) donePressed 
    if (self.doneTarget) 
        [self.doneTarget performSelector:self.doneSelector withObject:nil afterDelay:0];
    


- (void) addTargetForDoneButton: (id) target action: (SEL) action 
    self.doneTarget = target;
    self.doneSelector = action;

在视图控制器中使用自定义视图：

- (void)viewDidLoad

    [super viewDidLoad];
    UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    [button addTarget:self
               action:@selector(buttonPressed:)
     forControlEvents:UIControlEventTouchDown];
    [button setTitle:@"Show picker" forState:UIControlStateNormal];
    button.frame = CGRectMake(100, 50, 100, 40.0);
    [self.view addSubview:button];

    CGRect screenRect = [[UIScreen mainScreen] bounds];
    CGFloat screenWidth = screenRect.size.width;
    CGFloat screenHeight = screenRect.size.height;
    picker = [[DateTimePicker alloc] initWithFrame:CGRectMake(0, screenHeight/2 - 35, screenWidth, screenHeight/2 + 35)];
    [picker addTargetForDoneButton:self action:@selector(donePressed)];
    [self.view addSubview:picker];
    picker.hidden = YES;
    [picker setMode:UIDatePickerModeDate];


-(void)donePressed 
    picker.hidden = YES;


-(void)buttonPressed:(id)sender 
    picker.hidden = NO;

希望这会有所帮助。 :)

【讨论】：

我在尝试你的方法。我创建了一个自定义类，并将 .h 文件导入到一个新类中。但它说未定义的标识符选择器。我做错了吗？

#import #import "DateTimePicker.h" @interface ViewController : UIViewController DateTimePicker *dateTimePicker;

【参考方案4】：

有一个更优雅的解决方案。我不确定这是否是最近的（从 ios7 开始），但这对我来说非常有用。

TJDatePicker.h

@protocol TJDatePickerActionDelegate <NSObject>
- (void)cancel:(id)sender;
- (void)done:(id)sender;
@end

@interface TJDatePicker : UIDatePicker
@property (strong, nonatomic) UIView *navInputView;
@property (weak, nonatomic) id<TJDatePickerActionDelegate> actionDelegate;
@end

TJDatePicker.m

#import "TJDatePicker.h"

@interface TJDatePicker ()
@property (strong, nonatomic) TJButton *cancelButton;
@property (strong, nonatomic) TJButton *doneButton;
@end

@implementation TJDatePicker

- (id)initWithFrame:(CGRect)frame

    self = [super initWithFrame:frame];
    if (self)
    
        [self updateSubviews];
    

    return self;


- (void)layoutSubviews

    [super layoutSubviews];

    [self updateSubviews];


- (void)updateSubviews

    self.navInputView.frame = CGRectMake(0, 0, self.width, 45);
    self.cancelButton.frame = CGRectMake(5, 5, 80, 35);
    CGFloat width = 80;
    self.doneButton.frame = CGRectMake(CGRectGetMaxX(self.navInputView.frame) - width, self.cancelButton.frame.origin.y, width, self.cancelButton.height);


- (UIView *)navInputView

    if (!_navInputView)
    
        _navInputView = [[UIView alloc] init];
        _navInputView.backgroundColor = [UIColor whiteColor];

        self.cancelButton = [UIButton buttonWithType:UIButtonTypeCustom];
        [self.cancelButton setTitle:@"CANCEL" forState:UIControlStateNormal];
        [self.cancelButton addTarget:self action:@selector(cancelButtonPressed) forControlEvents:UIControlEventTouchUpInside];
        [_navInputView addSubview:self.cancelButton];

        self.doneButton = [UIButton buttonWithType:UIButtonTypeCustom];
        [self.doneButton setTitle:@"DONE" forState:UIControlStateNormal];
        [self.doneButton addTarget:self action:@selector(doneButtonPressed) forControlEvents:UIControlEventTouchUpInside];
        [_navInputView addSubview:self.doneButton];
    

    return _navInputView;


- (void)cancelButtonPressed

    [self.actionDelegate cancel:self];


- (void)doneButtonPressed

    [self.actionDelegate done:self];

然后在实施时...

self.datePicker = [[TJDatePicker alloc] init];
self.datePicker.actionDelegate = self;
self.textField.inputAccessoryView = self.datePicker.navInputView;

这里的关键是使用您计划将UIDatePicker 设置为的UITextField 中的inputAccessoryView。

【参考方案5】：

您可以使用 ActionSheetPicker 获得工具栏中的“完成”按钮。它是您自己构建的绝佳选择。

https://github.com/skywinder/ActionSheetPicker-3.0

【讨论】：

请帮助我理解它是如何不友好的？我在寻找答案时遇到了这个问题，发现对我来说最好的答案是使用图书馆。为什么其他人不想知道这个？

【参考方案6】：

成功！好的，我从不建议这样做，但这里是在您的特定教程代码中创建完成按钮的位置：

查看故事板，我们可以看到，当您单击“AddPersonTVC.h”（故事板右上角的类）中的“角色”框时，会弹出一个名为“RollPickerTVCell.h”的类

查看 RollPickerTVCell.h，我们注意到整个类是“CoreDataTableViewCell”的子类

@interface RolePickerTVCell : CoreDataTableViewCell <UIPickerViewDataSource, UIPickerViewDelegate>

查看类“CoreDataTableViewCell.m”，我们终于找到了我们的uibarbuttonitem！

UIBarButtonItem *doneBtn =[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(done:)];

【参考方案7】：

如果您正在处理表格视图单元格并且您没有使用 UITextField（因此您不会使用附件视图），这就是我所做的：

我创建了一个名为 GWDatePickerCell 的表格视图单元格，看起来像这样（不涉及 .nib 文件）。

GWDatePickerCell.h:

#import <UIKit/UIKit.h>

@interface GWDatePickerCell : UITableViewCell

@property (nonatomic, strong) UIDatePicker *datePicker;
@property (nonatomic, strong) UIToolbar *toolbar;
@property (nonatomic, strong) UIBarButtonItem *buttonDone;

@end

GWDatePickerCell.m:

    #import "GWDatePickerCell.h"

    @implementation GWDatePickerCell

    - (id) initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier 
        if(!(self=[super initWithStyle:style reuseIdentifier:reuseIdentifier])) return nil;

    _datePicker = [[UIDatePicker alloc] init];
    [_datePicker setMinuteInterval:5];
    [_datePicker setDatePickerMode:UIDatePickerModeDateAndTime];
    [self.contentView addSubview:_datePicker];

    _toolbar = [[UIToolbar alloc] init];
    _buttonDone = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:nil action:nil];
    _toolbar.items = @[[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil], _buttonDone];
    [self.contentView addSubview:_toolbar];

    return self;


- (void)layoutSubviews
    [super layoutSubviews];
    CGRect r = self.contentView.bounds;
    r.origin.y +=44;
    r.size.height = 216;
    CGRect tb = self.contentView.bounds;
    tb.size.height = 44;
    _datePicker.frame = r;
    _toolbar.frame = tb;


@end

现在在表格视图中创建单元格时我要做的就是：

为“完成”按钮指定 @selector。 在heightForRowAtIndexPath 中设置正确的单元格高度