IOS 七種手勢操作
今天為大家介紹一下IOS 的七種手勢，手勢在開發中經常用到，所以就簡單 通俗易懂的說下， 話不多說，直接看代碼：
1、UIGestureRecognizer 介紹
手勢識別在 iOS 中非常重要，他極大地提高了移動設備的使用便捷性。
iOS 系統在 3.2 以后，他提供了一些常用的手勢（UIGestureRecognizer 的子類），開發者可以直接使用他們進行手勢操作。
另外，可以通過繼承 UIGestureRecognizer 類，實現自定義手勢（手勢識別器類）。
PS：自定義手勢時，需要 #import <UIKit/UIGestureRecognizerSubclass.h>，一般需實現如下方法：
- (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;//以上方法在分類 UIGestureRecognizer (UIGestureRecognizerProtected) 中聲明，更多方法聲明請自行查看
UIGestureRecognizer 的繼承關系如下：
2、手勢狀態
在六種手勢識別中，只有一種手勢是離散型手勢，他就是 UITapGestureRecognizer。
離散型手勢的特點就是：一旦識別就無法取消，而且只會調用一次手勢操作事件（初始化手勢時指定的回調方法）。
換句話說其他五種手勢是連續型手勢，而連續型手勢的特點就是：會多次調用手勢操作事件，而且在連續手勢識別后可以取消手勢。從下圖可以看出兩者調用操作事件的次數是不同的：
手勢狀態枚舉如下：
typedef NS_ENUM(NSInteger, UIGestureRecognizerState) { UIGestureRecognizerStatePossible, // 尚未識別是何種手勢操作（但可能已經觸發了觸摸事件），默認狀態 UIGestureRecognizerStateBegan, // 手勢已經開始，此時已經被識別，但是這個過程中可能發生變化，手勢操作尚未完成 UIGestureRecognizerStateChanged, // 手勢狀態發生轉變 UIGestureRecognizerStateEnded, // 手勢識別操作完成（此時已經松開手指） UIGestureRecognizerStateCancelled, // 手勢被取消，恢復到默認狀態 UIGestureRecognizerStateFailed, // 手勢識別失敗，恢復到默認狀態 UIGestureRecognizerStateRecognized = UIGestureRecognizerStateEnded // 手勢識別完成，同UIGestureRecognizerStateEnded};對于離散型手勢 UITapGestureRecgnizer 要么被識別，要么失敗，點按（假設點按次數設置為1，并且沒有添加長按手勢）下去一次不松開則此時什么也不會發生，松開手指立即識別并調用操作事件，并且狀態為3（已完成）。
但是連續型手勢要復雜一些，就拿旋轉手勢來說，如果兩個手指點下去不做任何操作，此時并不能識別手勢（因為我們還沒旋轉）但是其實已經觸發了觸摸開始事件，此時處于狀態0；如果此時旋轉會被識別，也就會調用對應的操作事件，同時狀態變成1（手勢開始），但是狀態1只有一瞬間；緊接著狀態變為2（因為我們的旋轉需要持續一會），并且重復調用操作事件（如果在事件中打印狀態會重復打印2）；松開手指，此時狀態變為3，并調用1次操作事件。
3、使用手勢的步驟
使用手勢很簡單，分為三步：
PS：一個手勢只能對應一個 View，但是一個 View 可以有多個手勢。建議在真機上測試這些手勢，模擬器操作不太方便，可能導致認為手勢失效的情況。（模擬器測試捏合和旋轉手勢時，按住 option 鍵，再用觸摸板或鼠標操作）
4、舉例說明
功能描述：
附加到兩個圖片視圖 UIImageView 的有『拖動』、『捏合』、『旋轉』、『點按』；
而『輕掃』和『自定義手勢 KMGestureRecognizer』附加在根視圖 UIView 中。
拖動：進行當前圖片視圖位置移動
捏合：進行當前圖片視圖縮放
旋轉：進行當前圖片視圖角度旋轉
點按：雙擊恢復當前圖片視圖的縮放、角度旋轉、不透明度
長按：設置當前圖片視圖的不透明度為0.7
輕掃：左右輕掃設置兩個圖片視圖為居中，同時以垂直居中的特定偏移量定位
自定義手勢：撓癢功能，左右掃動共3次或以上，設置兩個圖片視圖為居中，同時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; //撓癢次數@property (assign, nonatomic) CGPoint currentTickleStart; //當前撓癢開始坐標位置@property (assign, nonatomic) Direction lastDirection; //最后一次撓癢方向@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]; //設置當前撓癢開始坐標位置}- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { //『當前撓癢開始坐標位置』和『移動后坐標位置』進行 X 軸值比較，得到是向左還是向右移動 UITouch *touch = [touches anyObject]; CGPoint tickleEnd = [touch locationInView:self.view]; CGFloat tickleSpacing = tickleEnd.x - _currentTickleStart.x; Direction currentDirection = tickleSpacing < 0 ? DirectionLeft : DirectionRight; //移動的 X 軸間距值是否符合要求，足夠大 if (ABS(tickleSpacing) >= kMinTickleSpacing) { //判斷是否有三次不同方向的動作，如果有則手勢結束，將執行回調方法 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(@"自定義手勢成功，將執行回調方法"); } } }}- (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;@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 - 處理手勢操作/** * 處理拖動手勢 * * @param recognizer 拖動手勢識別器對象實例 */- (void)handlePan:(UIPanGestureRecognizer *)recognizer { //視圖前置操作 [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) { //計算速度向量的長度，當他小于200時，滑行會很短 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計算一個終點 float slideFactor = 0.1 * slideMult; CGPoint finalPoint = CGPointMake(center.x + (velocity.x * slideFactor), center.y + (velocity.y * slideFactor)); //限制最小［cornerRadius］和最大邊界值［self.view.bounds.size.width - cornerRadius］，以免拖動出屏幕界限 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 動畫使 view 滑行到終點 [UIView animateWithDuration:slideFactor*2 delay:0 options:UIViewAnimationOptionCurveEaseOut animations:^{ recognizer.view.center = finalPoint; } completion:nil]; }}/** * 處理捏合手勢 * * @param recognizer 捏合手勢識別器對象實例 */- (void)handlePinch:(UIPinchGestureRecognizer *)recognizer { CGFloat scale = recognizer.scale; recognizer.view.transform = CGAffineTransformScale(recognizer.view.transform, scale, scale); //在已縮放大小基礎下進行累加變化；區別于：使用 CGAffineTransformMakeScale 方法就是在原大小基礎下進行變化 recognizer.scale = 1.0;}/** * 處理旋轉手勢 * * @param recognizer 旋轉手勢識別器對象實例 */- (void)handleRotation:(UIRotationGestureRecognizer *)recognizer { recognizer.view.transform = CGAffineTransformRotate(recognizer.view.transform, recognizer.rotation); recognizer.rotation = 0.0;}/** * 處理點按手勢 * * @param recognizer 點按手勢識別器對象實例 */- (void)handleTap:(UITapGestureRecognizer *)recognizer { UIView *view = recognizer.view; view.transform = CGAffineTransformMakeScale(1.0, 1.0); view.transform = CGAffineTransformMakeRotation(0.0); view.alpha = 1.0;}/** * 處理長按手勢 * * @param recognizer 點按手勢識別器對象實例 */- (void)handleLongPress:(UILongPressGestureRecognizer *)recognizer { //長按的時候，設置不透明度為0.7 recognizer.view.alpha = 0.7;}/** * 處理輕掃手勢 * * @param recognizer 輕掃手勢識別器對象實例 */- (void)handleSwipe:(UISwipeGestureRecognizer *)recognizer { //代碼塊方式封裝操作方法 void (^positionOperation)() = ^() { CGPoint newPoint = recognizer.view.center; newPoint.y -= 20.0; _imgV.center = newPoint; newPoint.y += 40.0; _imgV2.center = newPoint; }; //根據輕掃方向，進行不同控制 switch (recognizer.direction) { case UISwipeGestureRecognizerDirectionRight: { positionOperation(); break; } case UISwipeGestureRecognizerDirectionLeft: { positionOperation(); break; } case UISwipeGestureRecognizerDirectionUp: { break; } case UISwipeGestureRecognizerDirectionDown: { break; } }}/** * 處理自定義手勢 * * @param recognizer 自定義手勢識別器對象實例 */- (void)handleCustomGestureRecognizer:(KMGestureRecognizer *)recognizer { //代碼塊方式封裝操作方法 void (^positionOperation)() = ^() { CGPoint newPoint = recognizer.view.center; newPoint.x -= 20.0; _imgV.center = newPoint; newPoint.x += 40.0; _imgV2.center = newPoint; }; positionOperation();}#pragma mark - 綁定手勢操作/** * 綁定拖動手勢 * * @param imgVCustom 綁定到圖片視圖對象實例 */- (void)bindPan:(UIImageView *)imgVCustom { UIPanGestureRecognizer *recognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePan:)]; [imgVCustom addGestureRecognizer:recognizer];}/** * 綁定捏合手勢 * * @param imgVCustom 綁定到圖片視圖對象實例 */- (void)bindPinch:(UIImageView *)imgVCustom { UIPinchGestureRecognizer *recognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(handlePinch:)]; [imgVCustom addGestureRecognizer:recognizer]; //[recognizer requireGestureRecognizerToFail:imgVCustom.gestureRecognizers.firstObject];}/** * 綁定旋轉手勢 * * @param imgVCustom 綁定到圖片視圖對象實例 */- (void)bindRotation:(UIImageView *)imgVCustom { UIRotationGestureRecognizer *recognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(handleRotation:)]; [imgVCustom addGestureRecognizer:recognizer];}/** * 綁定點按手勢 * * @param imgVCustom 綁定到圖片視圖對象實例 */- (void)bindTap:(UIImageView *)imgVCustom { UITapGestureRecognizer *recognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTap:)]; //使用一根手指雙擊時，才觸發點按手勢識別器 recognizer.numberOfTapsRequired = 2; recognizer.numberOfTouchesRequired = 1; [imgVCustom addGestureRecognizer:recognizer];}/** * 綁定長按手勢 * * @param imgVCustom 綁定到圖片視圖對象實例 */- (void)bindLongPress:(UIImageView *)imgVCustom { UILongPressGestureRecognizer *recognizer = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongPress:)]; recognizer.minimumPressDuration = 0.5; //設置最小長按時間；默認為0.5秒 [imgVCustom addGestureRecognizer:recognizer];}/** * 綁定輕掃手勢；支持四個方向的輕掃，但是不同的方向要分別定義輕掃手勢 */- (void)bindSwipe { //向右輕掃手勢 UISwipeGestureRecognizer *recognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipe:)]; recognizer.direction = UISwipeGestureRecognizerDirectionRight; //設置輕掃方向；默認是 UISwipeGestureRecognizerDirectionRight，即向右輕掃 [self.view addGestureRecognizer:recognizer]; [recognizer requireGestureRecognizerToFail:_customGestureRecognizer]; //設置以自定義撓癢手勢優先識別 //向左輕掃手勢 recognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipe:)]; recognizer.direction = UISwipeGestureRecognizerDirectionLeft; [self.view addGestureRecognizer:recognizer]; [recognizer requireGestureRecognizerToFail:_customGestureRecognizer]; //設置以自定義撓癢手勢優先識別}/** * 綁定自定義撓癢手勢；判斷是否有三次不同方向的動作，如果有則手勢結束，將執行回調方法 */- (void)bingCustomGestureRecognizer { //當 recognizer.state 為 UIGestureRecognizerStateEnded 時，才執行回調方法 handleCustomGestureRecognizer: //_customGestureRecognizer = [KMGestureRecognizer new]; _customGestureRecognizer = [[KMGestureRecognizer alloc] initWithTarget:self action:@selector(handleCustomGestureRecognizer:)]; [self.view addGestureRecognizer:_customGestureRecognizer];}- (void)layoutUI { //圖片視圖 _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]; //圖片視圖 _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]; //為了處理手勢識別優先級的問題，這里需先綁定自定義撓癢手勢 [self bingCustomGestureRecognizer]; [self bindSwipe];}@end感謝閱讀，希望能幫助到大家，謝謝大家對本站的支持！
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