手势

定义

1. 为了完成手势识别,必须借助于手势识别器----UIGestureRecognizer
   2. 利用UIGestureRecognizer,能识别用户在某个view上做的一些常见手势
   3. UIGestureRecognizer是一个抽象类,定义了所有手势的基本行为,使用它的子类才能处理具体的手势

• UITapGestureRecognizer(敲击)

• UipinchGestureRecognizer(缩放)

• UIRotationGestureRecognizer(旋转)

• UISwipeGestureRecognizer(轻扫)

• UIPanGestureRecognizer(拖拽)

• UIScreenEdgePanGestureRecognizer

• UILongPRessGestureRecognizer(长按)

#import "ViewController.h"@interface ViewController ()<UIGestureRecognizerDelegate>@property (weak, nonatomic) IBOutlet UIView *iconView;@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];#warning 要实现手势操作userInteractionEnabled必须设为YES;    // 1.旋转手势//    [self testRotate];        // 2.捏合手势//    [self testPinch];        // 3.同时进行捏合和旋转    // 同时进行捏合和旋转需要实现代理方法//    [self testPinchAndRotate];        // 4.测试拖拽    [self testPan];    }#pragma mark - 拖拽手势- (void)testPan{    UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panView:)];        [_iconView addGestureRecognizer:pan];    }/** *  拖拽手势 */- (void)panView:(UIPanGestureRecognizer *)pan{    UIView *panView = pan.view; // 被拖拽的view        //1.view上移动的位置    CGPoint translation = [pan translationInView:panView];  // 在view上拖拽的位置    CGPoint center = panView.center;    center.x += translation.x;    center.y += translation.y;    panView.center = center;        // 2.清空移动的位置    [pan setTranslation:CGPointZero inView:panView];}#pragma mark - 代理方法- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{    return YES;}#pragma mark - 旋转和缩放- (void)testPinchAndRotate{    [self testPinch];        [self testRotate];}#pragma mark - 缩放手势- (void)testPinch{    UIPinchGestureRecognizer *pinch = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinch:)];#warning 如果只是实现单个缩放手势可以不用实现代理方法    pinch.delegate = self;        [_iconView addGestureRecognizer:pinch];}/** *  捏合 */- (void)pinch:(UIPinchGestureRecognizer *)pinch{    pinch.view.transform = CGAffineTransformScale(pinch.view.transform, pinch.scale, pinch.scale);    pinch.scale = 1;    // 可以认为每次捏合后缩放的比例都重新重置为1}#pragma mark - 旋转手势- (void)testRotate{    UIRotationGestureRecognizer *rotate = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotate:)];    [_iconView addGestureRecognizer:rotate];}/** *  旋转 */- (void)rotate:(UIRotationGestureRecognizer *)rotate{    rotate.view.transform = CGAffineTransformRotate(rotate.view.transform, rotate.rotation);    rotate.rotation = 0;    // 每次旋转后旋转的角度重置为0}@end