ios - 触发 UIButton 操作时如何传递自定义对象？

Question

我正在使用最新的 SDK 开发 iOS 应用程序。

我在以下方法上有一个选择器，我需要传递另一个参数:

- (MKAnnotationView *)mapView:(MKMapView *)theMapView viewForAnnotation:(id <MKAnnotation>)annotation
{
    NSLog(@"viewForAnnotation");

    MKAnnotationView *annotationView = nil;

    // if it's the user location, just return nil.
    if ([annotation isKindOfClass:[MKUserLocation class]])
        return nil;

    if ([annotation isKindOfClass:[ShopAnnotation class]])
    {
        // try to dequeue an existing pin view first
        static NSString *ReusableAnnotationIdentifier = @"reusableShopAnnotationIdentifier";

        MKPinAnnotationView *pinView = (MKPinAnnotationView *)[theMapView dequeueReusableAnnotationViewWithIdentifier:ReusableAnnotationIdentifier];

        if (!pinView)
        {
            // if an existing pin view was not available, create one
            MKPinAnnotationView *customPinView = [[MKPinAnnotationView alloc]
                                                  initWithAnnotation:annotation reuseIdentifier:ReusableAnnotationIdentifier];

            customPinView.pinColor = MKPinAnnotationColorPurple;
            customPinView.animatesDrop = YES;
            customPinView.canShowCallout = YES;

            // add a detail disclosure button to the callout which will open a new view controller page
            UIButton* rightButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
            [rightButton addTarget:self
                            action:@selector(showDetails:)
                  forControlEvents:UIControlEventTouchUpInside];

            customPinView.rightCalloutAccessoryView = rightButton;

            return customPinView;
        }
        else
        {
            pinView.annotation = annotation;
        }

        annotationView = pinView;
    }

    return annotationView;
}

我需要将一个对象传递给 showDetails::

        // add a detail disclosure button to the callout which will open a new view controller page
        UIButton* rightButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
        [rightButton addTarget:self
                        action:@selector(showDetails:)
              forControlEvents:UIControlEventTouchUpInside];

这就是 showDetails 的实现方式:

- (void) showDetails:(id)sender
{
    NSLog(@"Show Details");
    DetailViewController* mvc = [[DetailViewController alloc] initWithNibName:@"DetailViewController_iPhone" bundle:nil];

    mvc.delegate = self;

    [self presentModalViewController:mvc animated:YES];
}

这是ShopAnnotation界面:

#import <Foundation/Foundation.h>
#import <MapKit/MapKit.h>
#import <CoreData/CoreData.h>

@interface ShopAnnotation : NSObject <MKAnnotation>

@property (nonatomic, readonly) CLLocationCoordinate2D coordinate;
@property (nonatomic, readonly, strong) NSString *title;
@property (nonatomic, readonly, strong) NSString *subtitle;
@property (nonatomic, readonly, strong) NSManagedObject* shop;

-(id)initWithCoordinate:(CLLocationCoordinate2D) c
                  title:(NSString *) t
               subtitle:(NSString *) st
                   shop:(NSManagedObject*) shop;

@end

如何向 showDetails 添加另一个参数以及如何传递它？

showDetails 将是:

- (void) showDetails:(id)sender shop:(NSManagedObject*)shop

而且，这个(id)sender是什么？这是我可以用来传递此 NSManagedObject 的注释。

Answer 1

看看如何在“showDetails:”方法中传递“sender”参数？

为什么不子类化“UIButton”(例如将其命名为“VansFannelButton”)并为该新对象的“@interface”提供额外的 ivar这可以是您的有效负载。

然后你可以这样做:

- (void) showDetails: (VansFannelButton*) sender
{
    if (sender)
    {
         // do something with the managed object payload
         NSManagedObject * mObject = [sender payload];
    }
}