手勢識別器和UIImageView

Question

我發現此代碼可以在單擊圖像時更改圖像。

在.h中

@interface MyappViewController : UIViewController 
{
    NSDictionary *ddata;
    UIImageView *firstImage;
}
@property(retain,nonatomic) IBOutlet UIImageView *firstImage;

在.m中

- (void)viewDidLoad
{
    [super viewDidLoad];

    firstImage.userInteractionEnabled = YES;
    UIPinchGestureRecognizer *pgr = [[UIPinchGestureRecognizer alloc] 
                                     initWithTarget:self action:@selector(clickHandler:)];
    pgr.delegate = self;
    [firstImage addGestureRecognizer:pgr];
    [pgr release];
  //  [self clickHandler:self];  
}

-(void)animationDidStop:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context {
    /* destroy the transition view, set the image first */
    UIImageView *transitionImageView = (UIImageView *)context;
    self.firstImage.image = transitionImageView.image;
    [transitionImageView removeFromSuperview];
    transitionImageView = nil;
}

- (void)clickHandler:(id)sender {
    /* temporary view for the animation */
    NSLog(@"Click Handled ");

    UIImageView *transitionImageView = [[UIImageView alloc] initWithFrame:self.firstImage.frame];
    UIImage *image = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:[ddata objectForKey:@"pic"]]]];
    transitionImageView.image =  image;
    transitionImageView.alpha = 0.0f;
    [self.view addSubview:transitionImageView];

    [UIView beginAnimations:@"UpdateImages" context:transitionImageView];
    [UIView setAnimationDuration:2.0f];    
    transitionImageView.alpha = 1.0f;
    [UIView setAnimationDidStopSelector:@selector(animationDidStop:finished:context:)];    
    [UIView commitAnimations];
}

當我單擊圖像時，什么也沒有發生，但是如果我調用[self clickHandler：self]; 在ViewDidLoad中，圖像會更改。 我的問題是單擊圖像時未處理該單擊。

Answer 1

代替UIPinchGestureRecognizer您需要使用UITapGestureRecognizer 。 不要忘記設置所需的水龍頭數和手指數。 該文檔非常適合手勢識別器。