IOS 七种手势操作
今天为大家介绍一下IOS 的七种手势,手势在开发中经常用到,所以就简单 通俗易懂的说下, 话不多说,直接看代码:
1、UIGestureRecognizer 介绍
手势识别在 iOS 中非常重要,他极大地提高了移动设备的使用便捷性。
iOS 系统在 3.2 以后,他提供了一些常用的手势(UIGestureRecognizer 的子类),开发者可以直接使用他们进行手势操作。
另外,可以通过继承 UIGestureRecognizer 类,实现自定义手势(手势识别器类)。
PS:自定义手势时,需要 #import <UIKit/UIGestureRecognizerSubclass.h>,一般需实现如下方法:
- (void)reset; - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event; - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event; - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event; - (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event; //以上方法在分类 UIGestureRecognizer (UIGestureRecognizerProtected) 中声明,更多方法声明请自行查看
UIGestureRecognizer 的继承关系如下:
2、手势状态
在六种手势识别中,只有一种手势是离散型手势,他就是 UITapGestureRecognizer。
离散型手势的特点就是:一旦识别就无法取消,而且只会调用一次手势操作事件(初始化手势时指定的回调方法)。
换句话说其他五种手势是连续型手势,而连续型手势的特点就是:会多次调用手势操作事件,而且在连续手势识别后可以取消手势。从下图可以看出两者调用操作事件的次数是不同的:
手势状态枚举如下:
typedef NS_ENUM(NSInteger, UIGestureRecognizerState) { UIGestureRecognizerStatePossible, // 尚未识别是何种手势操作(但可能已经触发了触摸事件),默认状态 UIGestureRecognizerStateBegan, // 手势已经开始,此时已经被识别,但是这个过程中可能发生变化,手势操作尚未完成 UIGestureRecognizerStateChanged, // 手势状态发生转变 UIGestureRecognizerStateEnded, // 手势识别操作完成(此时已经松开手指) UIGestureRecognizerStateCancelled, // 手势被取消,恢复到默认状态 UIGestureRecognizerStateFailed, // 手势识别失败,恢复到默认状态 UIGestureRecognizerStateRecognized = UIGestureRecognizerStateEnded // 手势识别完成,同UIGestureRecognizerStateEnded };
对于离散型手势 UITapGestureRecgnizer 要么被识别,要么失败,点按(假设点按次数设置为1,并且没有添加长按手势)下去一次不松开则此时什么也不会发生,松开手指立即识别并调用操作事件,并且状态为3(已完成)。
但是连续型手势要复杂一些,就拿旋转手势来说,如果两个手指点下去不做任何操作,此时并不能识别手势(因为我们还没旋转)但是其实已经触发了触摸开始事件,此时处于状态0;如果此时旋转会被识别,也就会调用对应的操作事件,同时状态变成1(手势开始),但是状态1只有一瞬间;紧接着状态变为2(因为我们的旋转需要持续一会),并且重复调用操作事件(如果在事件中打印状态会重复打印2);松开手指,此时状态变为3,并调用1次操作事件。
3、使用手势的步骤
使用手势很简单,分为三步:
PS:一个手势只能对应一个 View,但是一个 View 可以有多个手势。建议在真机上测试这些手势,模拟器操作不太方便,可能导致认为手势失效的情况。(模拟器测试捏合和旋转手势时,按住 option 键,再用触摸板或鼠标操作)
4、举例说明
功能描述:
附加到两个图片视图 UIImageView 的有『拖动』、『捏合』、『旋转』、『点按』;
而『轻扫』和『自定义手势 KMGestureRecognizer』附加在根视图 UIView 中。
拖动:进行当前图片视图位置移动
捏合:进行当前图片视图缩放
旋转:进行当前图片视图角度旋转
点按:双击恢复当前图片视图的缩放、角度旋转、不透明度
长按:设置当前图片视图的不透明度为0.7
轻扫:左右轻扫设置两个图片视图为居中,同时以垂直居中的特定偏移量定位
自定义手势:挠痒功能,左右扫动共3次或以上,设置两个图片视图为居中,同时以水平居中的特定偏移量定位
效果如下:
KMGestureRecognizer.h
#import <UIKit/UIKit.h> typedef NS_ENUM(NSUInteger, Direction) { DirectionUnknown, DirectionLeft, DirectionRight }; @interface KMGestureRecognizer : UIGestureRecognizer @property (assign, nonatomic) NSUInteger tickleCount; //挠痒次数 @property (assign, nonatomic) CGPoint currentTickleStart; //当前挠痒开始坐标位置 @property (assign, nonatomic) Direction lastDirection; //最后一次挠痒方向 @end
KMGestureRecognizer.m
#import "KMGestureRecognizer.h" #import <UIKit/UIGestureRecognizerSubclass.h> @implementation KMGestureRecognizer #define kMinTickleSpacing 20.0 #define kMaxTickleCount 3 - (void)reset { _tickleCount = 0; _currentTickleStart = CGPointZero; _lastDirection = DirectionUnknown; if (self.state == UIGestureRecognizerStatePossible) { self.state = UIGestureRecognizerStateFailed; } } - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { UITouch *touch = [touches anyObject]; _currentTickleStart = [touch locationInView:self.view]; //设置当前挠痒开始坐标位置 } - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { //『当前挠痒开始坐标位置』和『移动后坐标位置』进行 X 轴值比较,得到是向左还是向右移动 UITouch *touch = [touches anyObject]; CGPoint tickleEnd = [touch locationInView:self.view]; CGFloat tickleSpacing = tickleEnd.x - _currentTickleStart.x; Direction currentDirection = tickleSpacing < 0 ? DirectionLeft : DirectionRight; //移动的 X 轴间距值是否符合要求,足够大 if (ABS(tickleSpacing) >= kMinTickleSpacing) { //判断是否有三次不同方向的动作,如果有则手势结束,将执行回调方法 if (_lastDirection == DirectionUnknown || (_lastDirection == DirectionLeft && currentDirection == DirectionRight) || (_lastDirection == DirectionRight && currentDirection == DirectionLeft)) { _tickleCount++; _currentTickleStart = tickleEnd; _lastDirection = currentDirection; if (_tickleCount >= kMaxTickleCount && self.state == UIGestureRecognizerStatePossible) { self.state = UIGestureRecognizerStateEnded; //NSLog(@"自定义手势成功,将执行回调方法"); } } } } - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event { [self reset]; } - (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event { [self reset]; } @end
ViewController.h
#import <UIKit/UIKit.h> #import "KMGestureRecognizer.h" @interface ViewController : UIViewController @property (strong, nonatomic) UIImageView *imgV; @property (strong, nonatomic) UIImageView *imgV2; @property (strong, nonatomic) KMGestureRecognizer *customGestureRecognizer; @end
ViewController.m
#import "ViewController.h" @interface ViewController () - (void)handlePan:(UIPanGestureRecognizer *)recognizer; - (void)handlePinch:(UIPinchGestureRecognizer *)recognizer; - (void)handleRotation:(UIRotationGestureRecognizer *)recognizer; - (void)handleTap:(UITapGestureRecognizer *)recognizer; - (void)handleLongPress:(UILongPressGestureRecognizer *)recognizer; - (void)handleSwipe:(UISwipeGestureRecognizer *)recognizer; - (void)handleCustomGestureRecognizer:(KMGestureRecognizer *)recognizer; - (void)bindPan:(UIImageView *)imgVCustom; - (void)bindPinch:(UIImageView *)imgVCustom; - (void)bindRotation:(UIImageView *)imgVCustom; - (void)bindTap:(UIImageView *)imgVCustom; - (void)bindLongPress:(UIImageView *)imgVCustom; - (void)bindSwipe; - (void)bingCustomGestureRecognizer; - (void)layoutUI; @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; [self layoutUI]; } - (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated. } #pragma mark - 处理手势操作 /** * 处理拖动手势 * * @param recognizer 拖动手势识别器对象实例 */ - (void)handlePan:(UIPanGestureRecognizer *)recognizer { //视图前置操作 [recognizer.view.superview bringSubviewToFront:recognizer.view]; CGPoint center = recognizer.view.center; CGFloat cornerRadius = recognizer.view.frame.size.width / 2; CGPoint translation = [recognizer translationInView:self.view]; //NSLog(@"%@", NSStringFromCGPoint(translation)); recognizer.view.center = CGPointMake(center.x + translation.x, center.y + translation.y); [recognizer setTranslation:CGPointZero inView:self.view]; if (recognizer.state == UIGestureRecognizerStateEnded) { //计算速度向量的长度,当他小于200时,滑行会很短 CGPoint velocity = [recognizer velocityInView:self.view]; CGFloat magnitude = sqrtf((velocity.x * velocity.x) + (velocity.y * velocity.y)); CGFloat slideMult = magnitude / 200; //NSLog(@"magnitude: %f, slideMult: %f", magnitude, slideMult); //e.g. 397.973175, slideMult: 1.989866 //基于速度和速度因素计算一个终点 float slideFactor = 0.1 * slideMult; CGPoint finalPoint = CGPointMake(center.x + (velocity.x * slideFactor), center.y + (velocity.y * slideFactor)); //限制最小[cornerRadius]和最大边界值[self.view.bounds.size.width - cornerRadius],以免拖动出屏幕界限 finalPoint.x = MIN(MAX(finalPoint.x, cornerRadius), self.view.bounds.size.width - cornerRadius); finalPoint.y = MIN(MAX(finalPoint.y, cornerRadius), self.view.bounds.size.height - cornerRadius); //使用 UIView 动画使 view 滑行到终点 [UIView animateWithDuration:slideFactor*2 delay:0 options:UIViewAnimationOptionCurveEaseOut animations:^{ recognizer.view.center = finalPoint; } completion:nil]; } } /** * 处理捏合手势 * * @param recognizer 捏合手势识别器对象实例 */ - (void)handlePinch:(UIPinchGestureRecognizer *)recognizer { CGFloat scale = recognizer.scale; recognizer.view.transform = CGAffineTransformScale(recognizer.view.transform, scale, scale); //在已缩放大小基础下进行累加变化;区别于:使用 CGAffineTransformMakeScale 方法就是在原大小基础下进行变化 recognizer.scale = 1.0; } /** * 处理旋转手势 * * @param recognizer 旋转手势识别器对象实例 */ - (void)handleRotation:(UIRotationGestureRecognizer *)recognizer { recognizer.view.transform = CGAffineTransformRotate(recognizer.view.transform, recognizer.rotation); recognizer.rotation = 0.0; } /** * 处理点按手势 * * @param recognizer 点按手势识别器对象实例 */ - (void)handleTap:(UITapGestureRecognizer *)recognizer { UIView *view = recognizer.view; view.transform = CGAffineTransformMakeScale(1.0, 1.0); view.transform = CGAffineTransformMakeRotation(0.0); view.alpha = 1.0; } /** * 处理长按手势 * * @param recognizer 点按手势识别器对象实例 */ - (void)handleLongPress:(UILongPressGestureRecognizer *)recognizer { //长按的时候,设置不透明度为0.7 recognizer.view.alpha = 0.7; } /** * 处理轻扫手势 * * @param recognizer 轻扫手势识别器对象实例 */ - (void)handleSwipe:(UISwipeGestureRecognizer *)recognizer { //代码块方式封装操作方法 void (^positionOperation)() = ^() { CGPoint newPoint = recognizer.view.center; newPoint.y -= 20.0; _imgV.center = newPoint; newPoint.y += 40.0; _imgV2.center = newPoint; }; //根据轻扫方向,进行不同控制 switch (recognizer.direction) { case UISwipeGestureRecognizerDirectionRight: { positionOperation(); break; } case UISwipeGestureRecognizerDirectionLeft: { positionOperation(); break; } case UISwipeGestureRecognizerDirectionUp: { break; } case UISwipeGestureRecognizerDirectionDown: { break; } } } /** * 处理自定义手势 * * @param recognizer 自定义手势识别器对象实例 */ - (void)handleCustomGestureRecognizer:(KMGestureRecognizer *)recognizer { //代码块方式封装操作方法 void (^positionOperation)() = ^() { CGPoint newPoint = recognizer.view.center; newPoint.x -= 20.0; _imgV.center = newPoint; newPoint.x += 40.0; _imgV2.center = newPoint; }; positionOperation(); } #pragma mark - 绑定手势操作 /** * 绑定拖动手势 * * @param imgVCustom 绑定到图片视图对象实例 */ - (void)bindPan:(UIImageView *)imgVCustom { UIPanGestureRecognizer *recognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePan:)]; [imgVCustom addGestureRecognizer:recognizer]; } /** * 绑定捏合手势 * * @param imgVCustom 绑定到图片视图对象实例 */ - (void)bindPinch:(UIImageView *)imgVCustom { UIPinchGestureRecognizer *recognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(handlePinch:)]; [imgVCustom addGestureRecognizer:recognizer]; //[recognizer requireGestureRecognizerToFail:imgVCustom.gestureRecognizers.firstObject]; } /** * 绑定旋转手势 * * @param imgVCustom 绑定到图片视图对象实例 */ - (void)bindRotation:(UIImageView *)imgVCustom { UIRotationGestureRecognizer *recognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(handleRotation:)]; [imgVCustom addGestureRecognizer:recognizer]; } /** * 绑定点按手势 * * @param imgVCustom 绑定到图片视图对象实例 */ - (void)bindTap:(UIImageView *)imgVCustom { UITapGestureRecognizer *recognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTap:)]; //使用一根手指双击时,才触发点按手势识别器 recognizer.numberOfTapsRequired = 2; recognizer.numberOfTouchesRequired = 1; [imgVCustom addGestureRecognizer:recognizer]; } /** * 绑定长按手势 * * @param imgVCustom 绑定到图片视图对象实例 */ - (void)bindLongPress:(UIImageView *)imgVCustom { UILongPressGestureRecognizer *recognizer = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongPress:)]; recognizer.minimumPressDuration = 0.5; //设置最小长按时间;默认为0.5秒 [imgVCustom addGestureRecognizer:recognizer]; } /** * 绑定轻扫手势;支持四个方向的轻扫,但是不同的方向要分别定义轻扫手势 */ - (void)bindSwipe { //向右轻扫手势 UISwipeGestureRecognizer *recognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipe:)]; recognizer.direction = UISwipeGestureRecognizerDirectionRight; //设置轻扫方向;默认是 UISwipeGestureRecognizerDirectionRight,即向右轻扫 [self.view addGestureRecognizer:recognizer]; [recognizer requireGestureRecognizerToFail:_customGestureRecognizer]; //设置以自定义挠痒手势优先识别 //向左轻扫手势 recognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipe:)]; recognizer.direction = UISwipeGestureRecognizerDirectionLeft; [self.view addGestureRecognizer:recognizer]; [recognizer requireGestureRecognizerToFail:_customGestureRecognizer]; //设置以自定义挠痒手势优先识别 } /** * 绑定自定义挠痒手势;判断是否有三次不同方向的动作,如果有则手势结束,将执行回调方法 */ - (void)bingCustomGestureRecognizer { //当 recognizer.state 为 UIGestureRecognizerStateEnded 时,才执行回调方法 handleCustomGestureRecognizer: //_customGestureRecognizer = [KMGestureRecognizer new]; _customGestureRecognizer = [[KMGestureRecognizer alloc] initWithTarget:self action:@selector(handleCustomGestureRecognizer:)]; [self.view addGestureRecognizer:_customGestureRecognizer]; } - (void)layoutUI { //图片视图 _imgV UIImage *img = [UIImage imageNamed:@"Emoticon_tusiji_icon"]; CGFloat cornerRadius = img.size.width; _imgV = [[UIImageView alloc] initWithImage:img]; _imgV.frame = CGRectMake(20.0, 20.0, cornerRadius * 2, cornerRadius * 2); _imgV.userInteractionEnabled = YES; _imgV.layer.masksToBounds = YES; _imgV.layer.cornerRadius = cornerRadius; _imgV.layer.borderWidth = 2.0; _imgV.layer.borderColor = [UIColor grayColor].CGColor; [self.view addSubview:_imgV]; //图片视图 _imgV2 img = [UIImage imageNamed:@"Emoticon_tusiji_icon2"]; cornerRadius = img.size.width; _imgV2 = [[UIImageView alloc] initWithImage:img]; _imgV2.frame = CGRectMake(20.0, 40.0 + _imgV.frame.size.height, cornerRadius * 2, cornerRadius * 2); _imgV2.userInteractionEnabled = YES; _imgV2.layer.masksToBounds = YES; _imgV2.layer.cornerRadius = cornerRadius; _imgV2.layer.borderWidth = 2.0; _imgV2.layer.borderColor = [UIColor orangeColor].CGColor; [self.view addSubview:_imgV2]; [self bindPan:_imgV]; [self bindPinch:_imgV]; [self bindRotation:_imgV]; [self bindTap:_imgV]; [self bindLongPress:_imgV]; [self bindPan:_imgV2]; [self bindPinch:_imgV2]; [self bindRotation:_imgV2]; [self bindTap:_imgV2]; [self bindLongPress:_imgV2]; //为了处理手势识别优先级的问题,这里需先绑定自定义挠痒手势 [self bingCustomGestureRecognizer]; [self bindSwipe]; } @end
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