我使用tap事件的时间非常敏感，因此我很好奇是否有可能在用户简单按下时激活UITapGestureRecognizer，而不是要求他们同时按下吗？
3 回答
一只斗牛犬
TA贡献1784条经验 获得超2个赞
创建您的自定义TouchDownGestureRecognizer子类，并在touches中实现手势。
TouchDownGestureRecognizer.h
#import <UIKit/UIKit.h>
@interface TouchDownGestureRecognizer : UIGestureRecognizer
@end
TouchDownGestureRecognizer.m
#import "TouchDownGestureRecognizer.h"
#import <UIKit/UIGestureRecognizerSubclass.h>
@implementation TouchDownGestureRecognizer
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
if (self.state == UIGestureRecognizerStatePossible) {
self.state = UIGestureRecognizerStateRecognized;
}
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
self.state = UIGestureRecognizerStateFailed;
}
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
self.state = UIGestureRecognizerStateFailed;
}
@end
实施：
#import "TouchDownGestureRecognizer.h"
TouchDownGestureRecognizer *touchDown = [[TouchDownGestureRecognizer alloc] initWithTarget:self action:@selector(handleTouchDown:)];
[yourView addGestureRecognizer:touchDown];
-(void)handleTouchDown:(TouchDownGestureRecognizer *)touchDown{
NSLog(@"Down");
}
迅捷的实现：
import UIKit
import UIKit.UIGestureRecognizerSubclass
class TouchDownGestureRecognizer: UIGestureRecognizer
{
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent)
{
if self.state == .Possible
{
self.state = .Recognized
}
}
override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent)
{
self.state = .Failed
}
override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent)
{
self.state = .Failed
}
}
这是2017年要粘贴的Swift语法：
import UIKit.UIGestureRecognizerSubclass
class SingleTouchDownGestureRecognizer: UIGestureRecognizer {
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent) {
if self.state == .possible {
self.state = .recognized
}
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent) {
self.state = .failed
}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent) {
self.state = .failed
}
}
请注意，这是的替代品UITap。所以在像这样的代码中
func add(tap v:UIView, _ action:Selector) {
let t = UITapGestureRecognizer(target: self, action: action)
v.addGestureRecognizer(t)
}
您可以安全地交换到...。
func add(hairtriggerTap v:UIView, _ action:Selector) {
let t = SingleTouchDownGestureRecognizer(target: self, action: action)
v.addGestureRecognizer(t)
}
测试表明它不会被多次调用。它可以作为替代品。您可以在两个通话之间进行交换。
三国纷争
TA贡献1804条经验 获得超7个赞
使用UILongPressGestureRecognizer并将其设置minimumPressDuration为0。在UIGestureRecognizerStateBegan状态期间，它将像着陆一样。
对于Swift 4
func setupTap() {
let touchDown = UILongPressGestureRecognizer(target:self, action: #selector(didTouchDown))
touchDown.minimumPressDuration = 0
view.addGestureRecognizer(touchDown)
}
@objc func didTouchDown(gesture: UILongPressGestureRecognizer) {
if gesture.state == .began {
doSomething()
}
}
对于Objective-C
例：
-(void)setupLongPress
{
self.longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(didLongPress:)];
self.longPress.minimumPressDuration = 0;
[self.view addGestureRecognizer:self.longPress];
}
-(void)didLongPress:(UILongPressGestureRecognizer *)gesture
{
if (gesture.state == UIGestureRecognizerStateBegan){
[self doSomething];
}
}
慕容森
TA贡献1853条经验 获得超18个赞
Swift（无子类）
这是Swift版本，类似于Rob Caraway的Objective-C答案。
想法是使用minimumPressDuration设置为零的长按手势识别器，而不是使用轻击手势识别器。这是因为长按手势识别器报告触摸开始事件，而点击手势没有报告。
import UIKit
class ViewController: UIViewController {
@IBOutlet weak var myView: UIView!
override func viewDidLoad() {
super.viewDidLoad()
// Add "long" press gesture recognizer
let tap = UILongPressGestureRecognizer(target: self, action: #selector(tapHandler))
tap.minimumPressDuration = 0
myView.addGestureRecognizer(tap)
}
// called by gesture recognizer
@objc func tapHandler(gesture: UITapGestureRecognizer) {
// handle touch down and touch up events separately
if gesture.state == .began {
// do something...
print("tap down")
} else if gesture.state == .ended { // optional for touch up event catching
// do something else...
print("tap up")
}
}
}
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