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:
复制代码 代码如下:
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:
创建手势识别器对象实例。创建时,指定一个回调方法,当手势开始,改变、或结束时,执行回调方法。
设置手势识别器对象实例的相关属性(可选部分)
添加到需要识别的 View 中。每个手势只对应一个 View,当屏幕触摸在 View 的边界内时,如果手势和预定的一样,那就会执行回调方法。
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@endKMGestureRecognizer.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]; }@endViewController.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;@endViewController.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:UIViewAnimationOptionCurveEaseOutanimations:^{ 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0.7recognizer.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:selfaction:@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:selfaction:@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:selfaction:@selector(handleCustomGestureRecognizer:)];[self.view addGestureRecognizer:_customGestureRecognizer]; }- (void)layoutUI {//图片视图 _imgVUIImage *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 _imgV2img = [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以上代码就是关于IOS手势操作(拖动、捏合、旋转、点按、长按、轻扫、自定义)的详解,希望对大家有所帮助。