8.3 Detecting Panning and Dragging Gestures

本文主要是介绍8.3 Detecting Panning and Dragging Gestures，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

拖动

@interface ViewController ()

@property (nonatomic, strong) UIPanGestureRecognizer *panGestureRecognizer;

@property (nonatomic, strong) UILabel *helloWorldLabel;

@end

@implementation ViewController

- (void) handlePanGestures:(UIPanGestureRecognizer*)paramSender{

NSLog(@"paramSender.view=%@",paramSender.view);

//UIGestureRecognizerStateEnded 时 x或y可能会是个不正常的值

if (paramSender.state != UIGestureRecognizerStateEnded && paramSender.state != UIGestureRecognizerStateFailed){

CGPoint location = [paramSender locationInView:paramSender.view.superview];

paramSender.view.center = location;

// self.helloWorldLabel.center = location;

}

-(UILabel*)getALable:(NSString*)text X:(NSInteger)x Y:(NSInteger)y

{

UILabel *lable = [[UILabel alloc] initWithFrame:CGRectMake(x, y, 200, 80)];

lable.text = text;

lable.backgroundColor = [UIColor blackColor];

lable.textColor = [UIColor whiteColor];

lable.textAlignment = NSTextAlignmentCenter;

lable.userInteractionEnabled = YES;

return lable;

}

-(UIPanGestureRecognizer*)getPanGestureRecognizer

{

UIPanGestureRecognizer * pgr = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePanGestures:)];

pgr.minimumNumberOfTouches = 1;

pgr.maximumNumberOfTouches = 1;

return pgr;

}

- (void)viewDidLoad

{

[super viewDidLoad];

self.view.backgroundColor = [UIColor whiteColor];

self.helloWorldLabel = [self getALable:@"Hello World" X:50 Y:50];

[self.view addSubview:self.helloWorldLabel];

UILabel * lable2 = [self getALable:@"Hello world 2" X:50 Y:200];

[self.view addSubview:lable2];

/* Create the Pan Gesture Recognizer */

self.panGestureRecognizer = [self getPanGestureRecognizer];

/* Add it to the view */

[self.helloWorldLabel addGestureRecognizer:self.panGestureRecognizer];

//这里要重新创建一个新的GestrueRecognizer对象，否则self.helloWorldLabel就识别不了了

[lable2 addGestureRecognizer:[self getPanGestureRecognizer]];

// [self.view addGestureRecognizer:self.panGestureRecognizer];

}

- (void)didReceiveMemoryWarning

{

[super didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

@end

由于有两个label，且都加上了PanGestureRecognizer,我们可以通知拉着他们移动

输出：

2014-04-10 10:56:48.026 cookbook[860:907] paramSender.view=<UILabel: 0x1f842ee0; frame = (50 50; 200 80); text = 'Hello World'; clipsToBounds = YES; gestureRecognizers = <NSArray: 0x1f844aa0>; layer = <CALayer: 0x1f842fc0>>

2014-04-10 10:56:48.041 cookbook[860:907] paramSender.view=<UILabel: 0x1f842ee0; frame = (97.5 49.5; 200 80); text = 'Hello World'; clipsToBounds = YES; gestureRecognizers = <NSArray: 0x1f844aa0>; layer = <CALayer: 0x1f842fc0>>

2014-04-10 10:56:48.043 cookbook[860:907] paramSender.view=<UILabel: 0x1f842ee0; frame = (98.5 50; 200 80); text = 'Hello World'; clipsToBounds = YES; gestureRecognizers = <NSArray: 0x1f844aa0>; layer = <CALayer: 0x1f842fc0>>

2014-04-10 10:56:48.057 cookbook[860:907] paramSender.view=<UILabel: 0x1f842ee0; frame = (98.5 50; 200 80); text = 'Hello World'; clipsToBounds = YES; gestureRecognizers = <NSArray: 0x1f844aa0>; layer = <CALayer: 0x1f842fc0>>

2014-04-10 10:56:48.073 cookbook[860:907] paramSender.view=<UILabel: 0x1f842ee0; frame = (99 51; 200 80); text = 'Hello World'; clipsToBounds = YES; gestureRecognizers = <NSArray: 0x1f844aa0>; layer = <CALayer: 0x1f842fc0>>

2014-04-10 10:56:48.089 cookbook[860:907] paramSender.view=<UILabel: 0x1f842ee0; frame = (99.5 51.5; 200 80); text = 'Hello World'; clipsToBounds = YES; gestureRecognizers = <NSArray: 0x1f844aa0>; layer = <CALayer: 0x1f842fc0>>

2014-04-10 10:56:48.105 cookbook[860:907] paramSender.view=<UILabel: 0x1f842ee0; frame = (100 52; 200 80); text = 'Hello World'; clipsToBounds = YES; gestureRecognizers = <NSArray: 0x1f844aa0>; layer = <CALayer: 0x1f842fc0>>

2014-04-10 10:56:48.121 cookbook[860:907] paramSender.view=<UILabel: 0x1f8441c0; frame = (50 200; 200 80); text = 'Hello world 2'; clipsToBounds = YES; gestureRecognizers = <NSArray: 0x1f844c40>; layer = <CALayer: 0x1f844250>>

2014-04-10 10:56:48.124 cookbook[860:907] paramSender.view=<UILabel: 0x1f842ee0; frame = (100.5 52.5; 200 80); text = 'Hello World'; clipsToBounds = YES; gestureRecognizers = <NSArray: 0x1f844aa0>; layer = <CALayer: 0x1f842fc0>>

2014-04-10 10:56:48.137 cookbook[860:907] paramSender.view=<UILabel: 0x1f8441c0; frame = (80 211; 200 80); text = 'Hello world 2'; clipsToBounds = YES; gestureRecognizers = <NSArray: 0x1f844c40>; layer = <CALayer: 0x1f844250>>

2014-04-10 10:56:48.139 cookbook[860:907] paramSender.view=<UILabel: 0x1f842ee0; frame = (101 53; 200 80); text = 'Hello World'; clipsToBounds = YES; gestureRecognizers = <NSArray: 0x1f844aa0>; layer = <CALayer: 0x1f842fc0>>