iOS--手勢識别UIGestureRecognizer

1.能用手勢識别就用，不要用touch…。

2.UIGestureRecognizer是一個抽象類，定義了所有手勢的基本行為沒使用它的自雷才能處理具體的手勢。

1.UITapGestureRecongnnizer(敲擊)

2.UIPinchGestureRecognizer(捏合，用于縮放)

3.UIPanGestureRecognizer（拖拽）

4.UISwipeGestureRecognizer(清掃)

#pragma mark - 代理方法
/**
 *  當點選view的時候,會先調用這個方法
 */
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
{
    CGPoint pos = [touch locationInView:touch.view];
    if (pos.x <= self.iconView.frame.size.width * ) {
        return YES;
    }
    return NO;
}

- (void)testTap
{
    // 1.建立手勢識别器對象
    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] init];
    // 連續敲擊2次,手勢才能識别成功
    tap.numberOfTapsRequired = ;
    tap.numberOfTouchesRequired = ;

    // 2.添加手勢識别器對象到對應的view
    [self.iconView addGestureRecognizer:tap];

    // 3.添加監聽方法(識别到了對應的手勢,就會調用監聽方法)
    [tap addTarget:self action:@selector(tapView)];
}
           

- (void)viewDidLoad
{
    [super viewDidLoad];

    UISwipeGestureRecognizer *swipe = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeView)];

    swipe.direction = UISwipeGestureRecognizerDirectionUp;

    [self.redView addGestureRecognizer:swipe];
}

- (void)swipeView
{
    NSLog(@"swipeView");
}

- (void)testLongPress
{
    UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] init];
    [longPress addTarget:self action:@selector(longPressView)];

    // 至少長按2秒
    longPress.minimumPressDuration = ;

    // 在觸發手勢之前,50px範圍内長按有效
    longPress.allowableMovement = ;

    [self.redView addGestureRecognizer:longPress];
}

- (void)longPressView
{
    NSLog(@"長按了紅色的view");
}
           

#import "MJViewController.h"

@interface MJViewController () <UIGestureRecognizerDelegate>
@property (weak, nonatomic) IBOutlet UIImageView *iconView;
@end

@implementation MJViewController

- (void)viewDidLoad
{
    [super viewDidLoad];

    [self testPinchAndRotate];
}

#pragma mark - 手勢識别器的代理方法

/**
 *  是否允許多個手勢識别器同時有效
 *  Simultaneously : 同時地
 */
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
    return YES;
}

#pragma mark - 縮放 + 旋轉
- (void)testPinchAndRotate
{
    [self testPinch];
    [self testRotate];
}

#pragma mark - 縮放手勢(捏合手勢)
- (void)testPinch
{
    UIPinchGestureRecognizer *pinch = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinchView:)];
    pinch.delegate = self;
    [self.iconView addGestureRecognizer:pinch];
}

- (void)pinchView:(UIPinchGestureRecognizer *)pinch
{
    pinch.view.transform = CGAffineTransformScale(pinch.view.transform, pinch.scale, pinch.scale);
    pinch.scale = ; // 這個真的很重要!!!!!
}

#pragma mark - 旋轉手勢
- (void)testRotate
{
    UIRotationGestureRecognizer *recognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotateView:)];
    recognizer.delegate = self;
    [self.iconView addGestureRecognizer:recognizer];
}

- (void)rotateView:(UIRotationGestureRecognizer *)recognizer
{
    recognizer.view.transform = CGAffineTransformRotate(recognizer.view.transform, recognizer.rotation);
    recognizer.rotation = ; // 這個很重要!!!!!
}

@end
           

#import "MJViewController.h"

@interface MJViewController ()
@property (weak, nonatomic) IBOutlet UIView *purpleView;

@end

@implementation MJViewController

- (void)viewDidLoad
{
    [super viewDidLoad];

    UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panView:)];
    [self.purpleView addGestureRecognizer:pan];
}

- (void)panView:(UIPanGestureRecognizer *)pan
{

    switch (pan.state) {
        case UIGestureRecognizerStateBegan: // 開始觸發手勢

            break;

        case UIGestureRecognizerStateEnded: // 手勢結束

            break;

        default:
            break;
    }

    // 1.在view上面挪動的距離
    CGPoint translation = [pan translationInView:pan.view];
    CGPoint center = pan.view.center;
    center.x += translation.x;
    center.y += translation.y;
    pan.view.center = center;

    // 2.清空移動的距離
    [pan setTranslation:CGPointZero inView:pan.view];
}

@end