mark - 学习笔记 - 拖动手势 - UIPanGestureRecognizer

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ViewController.m

#import "ViewController.h"

@interface ViewController ()
@property (nonatomic, strong)UIPanGestureRecognizer *panGestureRecognizer;
@property (nonatomic, strong)UILabel *helloWorldLabel;
@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    /*create a label*/
    CGRect labelFrame = CGRectMake(0.0f, 0.0f, 150.0f, 100.0f);
    self.helloWorldLabel = [[UILabel alloc] initWithFrame:labelFrame];
    self.helloWorldLabel.text = @"Hello World";
    self.helloWorldLabel.backgroundColor = [UIColor blackColor];
    self.helloWorldLabel.textColor = [UIColor whiteColor];
    self.helloWorldLabel.textAlignment = NSTextAlignmentCenter;
    /*make sure to enable user interaction;other,tap events won't be caught on this label*/
    self.helloWorldLabel.userInteractionEnabled = YES;
    [self.view addSubview:self.helloWorldLabel];
    
    /*create the Pan Gesture Recognizer*/
    self.panGestureRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePanGestures:)];
    self.panGestureRecognizer.minimumNumberOfTouches = 1;
    self.panGestureRecognizer.maximumNumberOfTouches = 1;
    [self.helloWorldLabel addGestureRecognizer:self.panGestureRecognizer];
}

-(void)handlePanGestures:(UIPanGestureRecognizer *)paramSender{
    if (paramSender.state != UIGestureRecognizerStateEnded && paramSender.state != UIGestureRecognizerStateFailed) {
        CGPoint location = [paramSender locationInView:paramSender.view.superview];
        paramSender.view.center = location;
    }
}


@end