Pass a NSDictionary as parameter to UITapGestureRe

问题:

I want to pass a NSArray as a parameter to UITapGestureRecognizer and access it in downloadOptionPressed method. How can I do this ?

The NSArray

NSArray *parameters = [NSArray arrayWithObjects:currentTrack, nil];

Creating the UITapGestureRecognizer

UITapGestureRecognizer *downloadOptionPressed = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(timeFrameLabelTapped:)];
    [downloadOption addGestureRecognizer:downloadOptionPressed];

The downloadOptionPressed method

-(void)downloadOptionPressed:(UIGestureRecognizer*)recognizer{

}

回答1:

Is there a reason you can't store the information in the owning view controller? Is it for abstraction?

You can always extend UITapGestureRecognizer to carry more data:

@interface UserDataTapGestureRecognizer : UITapGestureRecognizer
@property (nonatomic, strong) id userData;
@end

@implementation UserDataTapGestureRecognizer
@end

...

UserDataTapGestureRecognizer *downloadOptionPressed =
    [[UserDataTapGestureRecognizer alloc] initWithTarget:self
    action:@selector(timeFrameLabelTapped:)];
downloadOptionPressed.userData = parameters;

...

- (void)downloadOptionPressed:(UserDataTapGestureRecognizer *)recognizer {
    NSArray *parameters = recognizer.userData;
}

回答2:

You can use associated object to pass argument along with tap gesture instance.

You can check this objective-c-associated-objects

It will solve your problem.

回答3:

Sometimes with passing an index is enough, in that case the tag property view is your ally. In the following exampled I pretended to add a long press into a tableview cell. And once the event was triggered, I just wanted to know which cell was long pressed:

    let longPress = UILongPressGestureRecognizer(target: self, action: "longPress:")
    cell.tag = indexPath.row
    cell.addGestureRecognizer(longPress)

...

func longPress(guesture: UILongPressGestureRecognizer) {
    print("\(guesture.view!.tag)")} }