在点击背景时关闭UIPickerView

时间：2012-01-18 07:28:15

标签： iphone uipickerview uitapgesturerecognizer

我正在添加一个uipickerview作为主视图的子视图。要在点击背景视图时关闭选择器视图，我将在主视图中添加UITapGestureRecognizer。

我使用以下代码为主视图添加GestureRecognizer 

 UITapGestureRecognizer *gestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleSingleTap:)];
    gestureRecognizer.numberOfTapsRequired=1;
    gestureRecognizer.numberOfTouchesRequired=1;
    gestureRecognizer.delegate = self;
    [self.view addGestureRecognizer:gestureRecognizer];
    [gestureRecognizer release];

在handleSingleTap方法中，我正在解雇pickerview。

但问题是当我在pickerview内部点击时也会调用handleSingleTap。为避免这种情况，我使用了以下UIGestureRecognizer的委托方法

 -(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {

    /*
     *If the tap is inside a button return NO, to ensure the button click is detected.
     */
    if ([touch.view isKindOfClass:[UIButton class]]){
        return FALSE;
    }else if([touch.view isKindOfClass:[UIPickerView class]]) {

        return FALSE;

    }
    return TRUE;
}

它适用于按钮，但不适用于UIPickerView。任何人都可以帮我这个吗？

4 个答案:

答案 0 :(得分：1)

触摸的视图（touch.view）可能是pickerview的子视图之一。我试着测试一下：

[[pickerview subviews] containsObject: touch.view];

答案 1 :(得分：1)

我已根据您的特定要求编制了解决方案。

首先，我按照您的描述实现了您的代码并观察了您报告的相同问题 - 当您点击任何内容时，虚假的点按事件被发送到点击处理程序，包括UIButton。

这告诉我，UITapGestureRecogniser“窃取”应该转到UIButton的触摸，因此我认为最简单，最实用的解决方案是使用该功能对我有利，因此我为这两个分配了一个UITapGestureRecogniser pickerview和按钮也。我们刚刚丢弃的pickerview的水龙头，我们解析的其他水龙头并传递给按钮的水龙头处理程序。

注意 - 为方便起见，我在xib中分配了pickerview的数据源和委托。你也需要这样做，或者在代码中设置它。

标题 

//
//  ViewController.h
//  stackExchangeDemo
//
//  Created by unsynchronized on 18/01/12.
//  released to public domain via http://stackoverflow.com/a/8908028/830899
//

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController 
<UIPickerViewDelegate, UIPickerViewDataSource>

{
   UIButton *btn1; 
   UIPickerView *picker1;
}

@property (retain, nonatomic) IBOutlet UIButton *btn1;
@property (retain, nonatomic) IBOutlet UIPickerView *picker1;

@end

<强>实施 

//
//  ViewController.m
//  stackExchangeDemo
//
//  Created by unsynchronized on 18/01/12.
//  released to public domain via http://stackoverflow.com/a/8908028/830899
//

#import "ViewController.h"

@implementation ViewController
@synthesize btn1;
@synthesize picker1;

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Release any cached data, images, etc that aren't in use.
}

#pragma mark - View lifecycle

-(void) handleSingleTap:(UITapGestureRecognizer *) tapper {

    if (tapper.state == UIGestureRecognizerStateEnded) {
        NSLog(@"%@",NSStringFromSelector(_cmd));
    }

}

- (IBAction)handleButtonTap:(id)sender {
    NSLog(@"%@",NSStringFromSelector(_cmd));
}


-(void) handleButtonTapGesture:(UITapGestureRecognizer *) tapper {
    // call the buttons event handler

    UIControlEvents eventsToHandle = UIControlEventTouchUpInside;

    if (tapper.state == UIGestureRecognizerStateEnded) {
        UIButton *btn = (UIButton *) tapper.view;

        for (NSString *selName in [btn  actionsForTarget:self forControlEvent:eventsToHandle]) {

            SEL action = NSSelectorFromString(selName);
            if (action) {

                [self  performSelector:action withObject:btn1];
                break;
            }

        };  


    }

}

-(void) handleDummyTap:(UITapGestureRecognizer *) tapper {
    // silently ignore the tap event for this view.
}

-(void) setupTap:(UIView *) view action:(SEL)action {
    // assign custom tap event handler for given view.
    UITapGestureRecognizer *gestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:action];
    [view addGestureRecognizer:gestureRecognizer];
    [gestureRecognizer release];    
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    [self setupTap:self.view action:@selector(handleSingleTap:)];
    [self setupTap:picker1 action:@selector(handleDummyTap:)];
    [self setupTap:btn1 action:@selector(handleButtonTapGesture:)];



}



- (void)viewDidUnload
{
    [self setBtn1:nil];
    [self setPicker1:nil];
    [super viewDidUnload];
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
}

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
}

- (void)viewDidDisappear:(BOOL)animated
{
    [super viewDidDisappear:animated];
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    // Return YES for supported orientations
    return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}


#pragma mark @protocol UIPickerViewDataSource<NSObject>

// returns the number of 'columns' to display.
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView{
    return 1;
}

// returns the # of rows in each component..
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component {

    return 1;
}


#pragma mark @protocol UIPickerViewDelegate<NSObject>
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component {
    return [@"so long and thanks for all the fish".copy autorelease ];
}


- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component{
    NSLog(@"%@",NSStringFromSelector(_cmd));

}

- (void)dealloc {
    [btn1 release];
    [picker1 release];
    [super dealloc];
}
@end

答案 2 :(得分：0)

我只是在UIPickerView后面添加了一个不可见的UIControl实例，它覆盖了所有窗口，并获得了UIPickerView背后的所有触摸。如果被触摸，则UIPickerView和UIControl都被解除。 （SelectButton和CancelButton是UIPickerView的附件按钮。）

@property (strong, nonatomic) UIControl *touchRecognizer;

- (IBAction)showPicker:(id)sender {

    self.touchRecognizer = [[UIControl alloc]initWithFrame:self.view.window.bounds];
    [self.view.window addSubview:self.touchRecognizer];
    [self.touchRecognizer addTarget:self action:@selector(touchedOutsidePicker:) forControlEvents:UIControlEventTouchUpInside];

    [self.textField becomeFirstResponder];
}

- (IBAction)touchedOutsidePicker:(id)sender {
    [self.touchRecognizer removeFromSuperview];
    self.touchRecognizer = nil;

    [self.textField resignFirstResponder];
}

-(void)selectButtonPressed:(id)sender{
    [self.touchRecognizer removeFromSuperview];
    self.touchRecognizer = nil;

    [self.textField resignFirstResponder];

}

-(void)cancelButtonPressed:(id)sender{
    [self.touchRecognizer removeFromSuperview];
    self.touchRecognizer = nil;

    [self.textField resignFirstResponder];
}

答案 3 :(得分：0)

我在Swift中实现了以下内容：

    override func viewDidLoad()
        {
            super.viewDidLoad()
            let tap = UITapGestureRecognizer(target: self, action: #selector(handleTapGesture))
            tap.cancelsTouchesInView = false 
            view.addGestureRecognizer(tap)
        }

        func handleTapGesture(sender: AnyObject)
        {
            let subview = view?.hitTest(sender.locationInView(view), withEvent: nil)

            if(!(subview?.isDescendantOfView(timePicker) ?? false))
            {//might want to add a condition to make sure it's not your button ^^
                showTimePicker(false)//method which handles showing/hiding my picker 
            }
         }
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