如何拦截 MKMapView 或 UIWebView 对象上的触摸事件? [英] How to intercept touches events on a MKMapView or UIWebView objects?

问题描述

我不确定我做错了什么，但我尝试捕捉对 MKMapView 对象的触摸.我通过创建以下类对其进行子类化:

I'm not sure what I am doing wrong but I try to catch touches on a MKMapView object. I subclassed it by creating the following class :

#import <UIKit/UIKit.h>
#import <MapKit/MapKit.h>

@interface MapViewWithTouches : MKMapView {

}

- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *) event;   

@end

和实现:

#import "MapViewWithTouches.h"
@implementation MapViewWithTouches

- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *) event {

    NSLog(@"hello");
    //[super touchesBegan:touches   withEvent:event];

}
@end

但是看起来当我使用这个类时，我在控制台上看不到任何东西:

But it looks like when I use this class, I see nothing on the Console :

MapViewWithTouches *mapView = [[MapViewWithTouches alloc] initWithFrame:self.view.frame];
[self.view insertSubview:mapView atIndex:0];

知道我做错了什么吗?

推荐答案

我发现实现这一目标的最佳方法是使用手势识别器.事实证明，其他方法涉及大量不完美地复制 Apple 代码的黑客式编程，尤其是在多点触控的情况下.

The best way I have found to achieve this is with a Gesture Recognizer. Other ways turn out to involve a lot of hackish programming that imperfectly duplicates Apple's code, especially in the case of multitouch.

这就是我要做的:实现一个无法阻止且无法阻止其他手势识别器的手势识别器.将其添加到地图视图中，然后根据自己的喜好使用gestureRecognizer 的touchesBegan、touchesMoved 等.

Here's what I do: Implement a gesture recognizer that cannot be prevented and that cannot prevent other gesture recognizers. Add it to the map view, and then use the gestureRecognizer's touchesBegan, touchesMoved, etc. to your fancy.

WildcardGestureRecognizer * tapInterceptor = [[WildcardGestureRecognizer alloc] init];
tapInterceptor.touchesBeganCallback = ^(NSSet * touches, UIEvent * event) {
        self.lockedOnUserLocation = NO;
};
[mapView addGestureRecognizer:tapInterceptor];

WildcardGestureRecognizer.h

//
//  WildcardGestureRecognizer.h
//  Copyright 2010 Floatopian LLC. All rights reserved.
//

#import <Foundation/Foundation.h>

typedef void (^TouchesEventBlock)(NSSet * touches, UIEvent * event);

@interface WildcardGestureRecognizer : UIGestureRecognizer {
    TouchesEventBlock touchesBeganCallback;
}
@property(copy) TouchesEventBlock touchesBeganCallback;


@end

WildcardGestureRecognizer.m

//
//  WildcardGestureRecognizer.m
//  Created by Raymond Daly on 10/31/10.
//  Copyright 2010 Floatopian LLC. All rights reserved.
//

#import "WildcardGestureRecognizer.h"


@implementation WildcardGestureRecognizer
@synthesize touchesBeganCallback;

-(id) init{
    if (self = [super init])
    {
        self.cancelsTouchesInView = NO;
    }
    return self;
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    if (touchesBeganCallback)
        touchesBeganCallback(touches, event);
}

- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
{
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
}

- (void)reset
{
}

- (void)ignoreTouch:(UITouch *)touch forEvent:(UIEvent *)event
{
}

- (BOOL)canBePreventedByGestureRecognizer:(UIGestureRecognizer *)preventingGestureRecognizer
{
    return NO;
}

- (BOOL)canPreventGestureRecognizer:(UIGestureRecognizer *)preventedGestureRecognizer
{
    return NO;
}

@end

SWIFT 3

let tapInterceptor = WildCardGestureRecognizer(target: nil, action: nil)
tapInterceptor.touchesBeganCallback = {
    _, _ in
    self.lockedOnUserLocation = false
}
mapView.addGestureRecognizer(tapInterceptor)

WildCardGestureRecognizer.swift

import UIKit.UIGestureRecognizerSubclass

class WildCardGestureRecognizer: UIGestureRecognizer {

    var touchesBeganCallback: ((Set<UITouch>, UIEvent) -> Void)?

    override init(target: Any?, action: Selector?) {
        super.init(target: target, action: action)
        self.cancelsTouchesInView = false
    }

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

    override func canPrevent(_ preventedGestureRecognizer: UIGestureRecognizer) -> Bool {
        return false
    }

    override func canBePrevented(by preventingGestureRecognizer: UIGestureRecognizer) -> Bool {
        return false
    }
}

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