我有一个视图有一个UIPanGestureRecognizer垂直拖动视图。所以在识别器回调中，我只更新y坐标来移动它。这个视图的超级视图有一个UIPanGestureRecognizer，它将水平拖动视图，只是更新x坐标。
问题是第一个UIPanGestureRecognizer正在采取事件垂直移动视图，所以我不能使用superview手势。
我试过了
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer
shouldRecognizeSimultaneouslyWithGestureRecognizer:
(UIGestureRecognizer *)otherGestureRecognizer;
两者都会奏效，但我不希望如此。我希望只有在运动明显水平的情况下才能检测水平。所以如果UIPanGestureRecognizer有一个方向属性会很棒。
我怎样才能实现这种行为？我发现文档很混乱，所以也许有人可以在这里更好地解释它。
只需为垂直平移手势识别器执行此操作，它适用于我：
- (BOOL)gestureRecognizerShouldBegin:(UIPanGestureRecognizer *)panGestureRecognizer {
CGPoint velocity = [panGestureRecognizer velocityInView:someView];
return fabs(velocity.y) > fabs(velocity.x);
}
我拿了Lee Goodrich的answer并扩展它，因为我需要一个单向摇动。像这样用它：let pan = PanDirectionGestureRecognizer(direction: .vertical(.up), target: self, action: #selector(handleCellPan(_:)))
我还添加了一些评论，以便更清楚地了解实际做出的决定。
import UIKit.UIGestureRecognizerSubclass
enum PanVerticalDirection {
case either
case up
case down
}
enum PanHorizontalDirection {
case either
case left
case right
}
enum PanDirection {
case vertical(PanVerticalDirection)
case horizontal(PanHorizontalDirection)
}
class PanDirectionGestureRecognizer: UIPanGestureRecognizer {
let direction: PanDirection
init(direction: PanDirection, target: AnyObject, action: Selector) {
self.direction = direction
super.init(target: target, action: action)
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent) {
super.touchesMoved(touches, with: event)
if state == .began {
let vel = velocity(in: view)
switch direction {
// expecting horizontal but moving vertical, cancel
case .horizontal(_) where fabs(vel.y) > fabs(vel.x):
state = .cancelled
// expecting vertical but moving horizontal, cancel
case .vertical(_) where fabs(vel.x) > fabs(vel.y):
state = .cancelled
// expecting horizontal and moving horizontal
case .horizontal(let hDirection):
switch hDirection {
// expecting left but moving right, cancel
case .left where vel.x > 0: state = .cancelled
// expecting right but moving left, cancel
case .right where vel.x < 0: state = .cancelled
default: break
}
// expecting vertical and moving vertical
case .vertical(let vDirection):
switch vDirection {
// expecting up but moving down, cancel
case .up where vel.y > 0: state = .cancelled
// expecting down but moving up, cancel
case .down where vel.y < 0: state = .cancelled
default: break
}
}
}
}
}
以下是我的解决方法：
首先，我启用了同时PanGesture识别。
-(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
return YES;
然后我隔离水平和垂直平移手势（累加器是NSMutableArray属性）：
- (void)verticalPan :(UIPanGestureRecognizer *) sender {
CGPoint touch = [sender translationInView:self];
NSValue *value = [NSValue valueWithCGPoint:touch];
[accumulator addObject:value];
int firstXObjectValue = (int)[[accumulator objectAtIndex:0] CGPointValue].x ;
int lastXObjectValue = (int)[[accumulator lastObject] CGPointValue].x;
int firstYObjectValue = (int)[[accumulator objectAtIndex:0] CGPointValue].y;
int lastYObjectValue = (int)[[accumulator lastObject] CGPointValue].y;
if (abs(lastYObjectValue - firstYObjectValue) < 4 && abs(lastXObjectValue - firstXObjectValue) > 4) {
NSLog(@"Horizontal Pan");
//do something here
}
else if (abs(lastYObjectValue - firstYObjectValue) > 4 && abs(lastXObjectValue - firstXObjectValue) < 4){
NSLog(@"Vertical Pan");
//do something here
}
if (accumulator.count > 3)
[accumulator removeAllObjects];
我举了一个例子：
let pangesture = UIPanGestureRecognizer(target: self, action: "dragview:")
yourview.addGestureRecognizer(pangesture)
func dragview(panGestureRecognizer:UIPanGestureRecognizer)
{
let touchlocation = panGestureRecognizer.locationInView(parentview)
yourview.center.y = touchlocation.y //x for horizontal
}
- (void)dragAction:(UIPanGestureRecognizer *)gesture{
UILabel *label = (UILabel *)gesture.view;
CGPoint translation = [gesture translationInView:label];
label.center = CGPointMake(label.center.x + translation.x,
label.center.y + 0);
[gesture setTranslation:CGPointZero inView:label];}
我为只需要水平滚动的对象创建了PanGestureRecognizer @selector动作方法。
UIPanGestureRecognizer *gesture = [[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(smileyDragged:)];
[buttonObject addGestureRecognizer:gesture];
迅捷的方式
override func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
if let panGestureRecognizer = gestureRecognizer as? UIPanGestureRecognizer {
return isVerticalGesture(panGestureRecognizer)
}
return false
}
private func isVerticalGesture(_ recognizer: UIPanGestureRecognizer) -> Bool {
let translation = recognizer.translation(in: superview!)
if fabs(translation.y) > fabs(translation.x) {
return true
}
return false
}
Swift 4.2
解决方案仅适用于垂直支撑平移手势，与水平相同。
let pan = UIPanGestureRecognizer(target: self, action: #selector(test1))
pan.cancelsTouchesInView = false
panView.addGestureRecognizer(pan)
解决方案1：
@objc func panAction(pan: UIPanGestureRecognizer) {
let velocity = pan.velocity(in: panView)
guard abs(velocity.y) > abs(velocity.x) else {
return
}
}
解决方案2：
[UISwipeGestureRecognizer.Direction.left, .right].forEach { direction in
let swipe = UISwipeGestureRecognizer(target: self, action: #selector(swipeAction))
swipe.direction = direction
panView.addGestureRecognizer(swipe)
pan.require(toFail: swipe)
}
然后滑动手势将吞下平移手势。当然，你不需要在swipeAction做任何事情。
对于你所有的Swift用户，这将完成工作:)
import Foundation
import UIKit.UIGestureRecognizerSubclass
class DirectionPanGestureRecognizer: UIPanGestureRecognizer {
let kDirectionPanThreshold = CGFloat(5)
var drag = true
var moveX = CGFloat(0)
var moveY = CGFloat(0)
override init(target: AnyObject, action: Selector) {
super.init(target: target, action: action)
}
override func touchesMoved(touches: NSSet, withEvent event: UIEvent) {
super.touchesMoved(touches, withEvent: event)
if state == .Failed {
return
}
let nowPoint = touches.anyObject()?.locationInView(view)
let prevPoint = touches.anyObject()?.previousLocationInView(view)
moveX += prevPoint!.x - nowPoint!.x
moveY += prevPoint!.y - nowPoint!.y
if !drag {
if abs(moveX) > kDirectionPanThreshold {
state = .Failed
} else {
drag = true
}
}
}
override func reset() {
super.reset()
moveX = 0
moveY = 0
drag = false
}
}
我采用了Lee Goodrich的优秀answer并移植到Swift 3
import UIKit
import UIKit.UIGestureRecognizerSubclass
enum PanDirection {
case vertical
case horizontal
}
class PanDirectionGestureRecognizer: UIPanGestureRecognizer {
let direction : PanDirection
init(direction: PanDirection, target: AnyObject, action: Selector) {
self.direction = direction
super.init(target: target, action: action)
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent) {
super.touchesMoved(touches, with: event)
if state == .began {
let vel = velocity(in: self.view!)
switch direction {
case .horizontal where fabs(vel.y) > fabs(vel.x):
state = .cancelled
case .vertical where fabs(vel.x) > fabs(vel.y):
state = .cancelled
default:
break
}
}
}
}
我很乐意分享我的方法，因为所有其他方法都基于UIGestureRecognizerDelegate或子类化UIPanGestureRecognizer。
我的方法基于运行时和调配。我对这种方法并不是100％肯定，但你可以自己测试和改进它。
只用一行代码设置任何UIPanGestureRecognizer的方向：
UITableView().panGestureRecognizer.direction = UIPanGestureRecognizer.Direction.vertical
使用pod 'UIPanGestureRecognizerDirection'或代码：
public extension UIPanGestureRecognizer {
override open class func initialize() {
super.initialize()
guard self === UIPanGestureRecognizer.self else { return }
func replace(_ method: Selector, with anotherMethod: Selector, for clаss: AnyClass) {
let original = class_getInstanceMethod(clаss, method)
let swizzled = class_getInstanceMethod(clаss, anotherMethod)
switch class_addMethod(clаss, method, method_getImplementation(swizzled), method_getTypeEncoding(swizzled)) {
case true:
class_replaceMethod(clаss, anotherMethod, method_getImplementation(original), method_getTypeEncoding(original))
case false:
method_exchangeImplementations(original, swizzled)
}
}
let selector1 = #selector(UIPanGestureRecognizer.touchesBegan(_:with:))
let selector2 = #selector(UIPanGestureRecognizer.swizzling_touchesBegan(_:with:))
replace(selector1, with: selector2, for: self)
let selector3 = #selector(UIPanGestureRecognizer.touchesMoved(_:with:))
let selector4 = #selector(UIPanGestureRecognizer.swizzling_touchesMoved(_:with:))
replace(selector3, with: selector4, for: self)
}
@objc private func swizzling_touchesBegan(_ touches: Set<UITouch>, with event: UIEvent) {
self.swizzling_touchesBegan(touches, with: event)
guard direction != nil else { return }
touchesBegan = true
}
@objc private func swizzling_touchesMoved(_ touches: Set<UITouch>, with event: UIEvent) {
self.swizzling_touchesMoved(touches, with: event)
guard let direction = direction, touchesBegan == true else { return }
defer {
touchesBegan = false
}
let forbiddenDirectionsCount = touches
.flatMap({ ($0.location(in: $0.view) - $0.previousLocation(in: $0.view)).direction })
.filter({ $0 != direction })
.count
if forbiddenDirectionsCount > 0 {
state = .failed
}
}
}
public extension UIPanGestureRecognizer {
public enum Direction: Int {
case horizontal = 0
case vertical
}
private struct UIPanGestureRecognizerRuntimeKeys {
static var directions = "\(#file)+\(#line)"
static var touchesBegan = "\(#file)+\(#line)"
}
public var direction: UIPanGestureRecognizer.Direction? {
get {
let object = objc_getAssociatedObject(self, &UIPanGestureRecognizerRuntimeKeys.directions)
return object as? UIPanGestureRecognizer.Direction
}
set {
let policy = objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN_NONATOMIC
objc_setAssociatedObject(self, &UIPanGestureRecognizerRuntimeKeys.directions, newValue, policy)
}
}
fileprivate var touchesBegan: Bool {
get {
let object = objc_getAssociatedObject(self, &UIPanGestureRecognizerRuntimeKeys.touchesBegan)
return (object as? Bool) ?? false
}
set {
let policy = objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN_NONATOMIC
objc_setAssociatedObject(self, &UIPanGestureRecognizerRuntimeKeys.touchesBegan, newValue, policy)
}
}
}
fileprivate extension CGPoint {
var direction: UIPanGestureRecognizer.Direction? {
guard self != .zero else { return nil }
switch fabs(x) > fabs(y) {
case true: return .horizontal
case false: return .vertical
}
}
static func -(lhs: CGPoint, rhs: CGPoint) -> CGPoint {
return CGPoint(x: lhs.x - rhs.x, y: lhs.y - rhs.y)
}
}
我试过这个：根据问题描述，这对我有用
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
if gestureRecognizer is UIPanGestureRecognizer {
return true
} else {
return false
}
}
我在@LocoMike提供的答案中创建了一个子类化的解决方案，但是使用了由@Hejazi提供的更有效的初始速度检测机制。我也使用Swift，但如果需要，这应该很容易转换为Obj-C。
优于其他解决方案：
这是代码：
import UIKit.UIGestureRecognizerSubclass
enum PanDirection {
case vertical
case horizontal
}
class PanDirectionGestureRecognizer: UIPanGestureRecognizer {
let direction: PanDirection
init(direction: PanDirection, target: AnyObject, action: Selector) {
self.direction = direction
super.init(target: target, action: action)
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent) {
super.touchesMoved(touches, with: event)
if state == .began {
let vel = velocity(in: view)
switch direction {
case .horizontal where fabs(vel.y) > fabs(vel.x):
state = .cancelled
case .vertical where fabs(vel.x) > fabs(vel.y):
state = .cancelled
default:
break
}
}
}
}
用法示例：
let panGestureRecognizer = PanDirectionGestureRecognizer(direction: .horizontal, target: self, action: #selector(handlePanGesture(_:)))
panGestureRecognizer.cancelsTouchesInView = false
self.view.addGestureRecognizer(panGestureRecognizer)
func handlePanGesture(_ pan: UIPanGestureRecognizer) {
let percent = max(pan.translation(in: view).x, 0) / view.frame.width
switch pan.state {
case .began:
...
}
我走得更远，向Pan Gesture指点：
enum PanDirection {
case up
case left
case right
case down
}
class PanDirectionGestureRecognizer: UIPanGestureRecognizer {
fileprivate let direction: PanDirection
init(direction: PanDirection, target: AnyObject, action: Selector) {
self.direction = direction
super.init(target: target, action: action)
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent) {
super.touchesMoved(touches, with: event)
guard state != .failed else { return }
let vel = velocity(in: view)
let velocities: [PanDirection: CGFloat]
= [.up: -vel.y,
.left: -vel.x,
.right: vel.x,
.down: vel.y]
let sortedKeys = velocities.sorted { $0.1 < $1.1 }
if let key = sortedKeys.last?.key,
key != direction {
state = .cancelled
}
}
}
（使用：https://github.com/fastred/SloppySwiper和https://stackoverflow.com/a/30607392/5790492）
PanGestureRecognizer接口包含以下定义：
unsigned int _canPanHorizontally:1;
unsigned int _canPanVertically:1;
我没有检查这个，但也许它可以通过子类访问。
我想出了创建UIPanGestureRecognizer的子类
方向PanGestureRecognizer：
#import <Foundation/Foundation.h>
#import <UIKit/UIGestureRecognizerSubclass.h>
typedef enum {
DirectionPangestureRecognizerVertical,
DirectionPanGestureRecognizerHorizontal
} DirectionPangestureRecognizerDirection;
@interface DirectionPanGestureRecognizer : UIPanGestureRecognizer {
BOOL _drag;
int _moveX;
int _moveY;
DirectionPangestureRecognizerDirection _direction;
}
@property (nonatomic, assign) DirectionPangestureRecognizerDirection direction;
@end
方向PanGestureRecognizer.m：
#import "DirectionPanGestureRecognizer.h"
int const static kDirectionPanThreshold = 5;
@implementation DirectionPanGestureRecognizer
@synthesize direction = _direction;
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
[super touchesMoved:touches withEvent:event];
if (self.state == UIGestureRecognizerStateFailed) return;
CGPoint nowPoint = [[touches anyObject] locationInView:self.view];
CGPoint prevPoint = [[touches anyObject] previousLocationInView:self.view];
_moveX += prevPoint.x - nowPoint.x;
_moveY += prevPoint.y - nowPoint.y;
if (!_drag) {
if (abs(_moveX) > kDirectionPanThreshold) {
if (_direction == DirectionPangestureRecognizerVertical) {
self.state = UIGestureRecognizerStateFailed;
}else {
_drag = YES;
}
}else if (abs(_moveY) > kDirectionPanThreshold) {
if (_direction == DirectionPanGestureRecognizerHorizontal) {
self.state = UIGestureRecognizerStateFailed;
}else {
_drag = YES;
}
}
}
}
- (void)reset {
[super reset];
_drag = NO;
_moveX = 0;
_moveY = 0;
}
@end
这将仅在用户开始拖动所选行为时触发手势。将direction属性设置为正确的值，然后全部设置。
我试图用UIPanGestureRecognizer水平约束有效区域。
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
if ([gestureRecognizer isKindOfClass:[UIPanGestureRecognizer class]]) {
UIPanGestureRecognizer *panGesture = (UIPanGestureRecognizer *)gestureRecognizer;
CGPoint velocity = [panGesture velocityInView:panGesture.view];
double radian = atan(velocity.y/velocity.x);
double degree = radian * 180 / M_PI;
double thresholdAngle = 20.0;
if (fabs(degree) > enableThreshold) {
return NO;
}
}
return YES;
}
然后，只能在水平阈值范围内滑动才能触发此平移手势。
Swift 3.0回答：只是处理垂直手势
override func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
if let pan = gestureRecognizer as? UIPanGestureRecognizer {
let velocity = pan.velocity(in: self)
return fabs(velocity.y) > fabs(velocity.x)
}
return true
}
以下解决方案解决了我的问题：
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
if ([gestureRecognizer.view isEqual:self.view] && [otherGestureRecognizer.view isEqual:self.tableView]) {
return NO;
}
return YES;
}
这实际上只是检查pan是否在主视图或tableView上。
斯威夫特3版的李的懒惰回答
import UIKit
import UIKit.UIGestureRecognizerSubclass
enum PanDirection {
case vertical
case horizontal
}
class UIPanDirectionGestureRecognizer: UIPanGestureRecognizer {
let direction : PanDirection
init(direction: PanDirection, target: AnyObject, action: Selector) {
self.direction = direction
super.init(target: target, action: action)
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent) {
super.touchesMoved(touches, with: event)
if state == .began {
let vel = velocity(in: self.view!)
switch direction {
case .horizontal where fabs(vel.y) > fabs(vel.x):
state = .cancelled
case .vertical where fabs(vel.x) > fabs(vel.y):
state = .cancelled
default:
break
}
}
}
}
你可以通过UIView找到在UIPanGestureRecognizer上拖动的方向。请按照代码。
- (void)viewDidLoad {
[super viewDidLoad];
flipFoward = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(doFlipForward:)];
[flipFoward setMaximumNumberOfTouches:1];
[flipFoward setMinimumNumberOfTouches:1];
[flipFoward setDelegate:self];
[self.view addGestureRecognizer:flipFoward];
flipBack = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(doFlipBack:)];
[flipBack setMaximumNumberOfTouches:1];
[flipBack setMinimumNumberOfTouches:1];
[flipBack setDelegate:self];
[self.view addGestureRecognizer:flipBack];
}
#pragma mark -
#pragma mark RESPONDER
-(void)doFlipForward:(UIGestureRecognizer *)aGestureRecognizer{
NSLog(@"doFlipForward");
if([(UIPanGestureRecognizer*)aGestureRecognizer state] == UIGestureRecognizerStateBegan) {
NSLog(@"UIGestureRecognizerStateBegan");
}
if([(UIPanGestureRecognizer*)aGestureRecognizer state] == UIGestureRecognizerStateChanged) {
NSLog(@"UIGestureRecognizerStateChanged");
}
if([(UIPanGestureRecognizer*)aGestureRecognizer state] == UIGestureRecognizerStateEnded) {
NSLog(@"UIGestureRecognizerStateEnded");
}
}
-(void)doFlipBack:(UIGestureRecognizer *)aGestureRecognizer{
NSLog(@"doFlipBack");
if([(UIPanGestureRecognizer*)aGestureRecognizer state] == UIGestureRecognizerStateBegan) {
NSLog(@"UIGestureRecognizerStateBegan1");
}
if([(UIPanGestureRecognizer*)aGestureRecognizer state] == UIGestureRecognizerStateChanged) {
NSLog(@"UIGestureRecognizerStateChanged1");
}
if([(UIPanGestureRecognizer*)aGestureRecognizer state] == UIGestureRecognizerStateEnded) {
NSLog(@"UIGestureRecognizerStateEnded1");
}
}
#pragma mark -
#pragma mark DELEGATE
-(BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer{
CGSize size = [self.view bounds].size;
CGFloat touchX = [gestureRecognizer locationInView:self.view].x;
if((gestureRecognizer == flipFoward)
&& touchX >= (size.width - 88.0f))
{
return YES;
}
if((gestureRecognizer == flipBack)
&& touchX <= 88.0f)
{
return YES;
}
return NO;
}
你可以使用简单的panGestureRecognizer。无需使用pandirectionregognizer或其他东西。只需使用translationInview的y值下面的代码仅向上和向下移动拖动视图
- (void)gesturePan_Handle:(UIPanGestureRecognizer *)gesture {
if (gesture.state == UIGestureRecognizerStateChanged) {
CGPoint translation = [gesture translationInView:gesture.view];
recognizer.view.center = CGPointMake(recognizer.view.center.x, recognizer.view.center.y + translation.y);
[gesture setTranslation:CGPointMake(0, 0) inView:gesture.view];
}
}