Question

我已经像这样实施了calloutAccessoryControlTapped：

- (void)mapView:(MKMapView *)mapView annotationView:(MKAnnotationView *)view
calloutAccessoryControlTapped:(UIControl *)control
{
    NSLog(@"calloutAccessoryControlTapped: annotation = %@", view.annotation.title);
    if([_delegate respondsToSelector:@selector(mapView:didClickPinButton:)])
    {
        NSString *titleStr =  [(DisplayMap *)view.annotation title];
        [_delegate performSelector:@selector(mapView:didClickPinButton:)withObject:titleStr];
    }
}

当我点击pin的按钮时，它会转到主视图控制器上的方法mapView:didClickPinButton并显示错误：

线程1：EXC_BAD_ACCESS（代码= 1，地址= 0x ......）

这是mapView:didClickPinButton:方法：

- (void) mapView: (MapView *) mapView didClickPinButton:(NSString *) title
{
    NSLog(@"bsn name-->%@",title);
    for(int i=0;i<[self.categoryListArray count];i++)
    {
        NSMutableDictionary *couponDetail = [self.categoryListArray objectAtIndex:i];
        if([[couponDetail objectForKey:@"category_name"] isEqualToString:title])
        {
            NSNumber *coupon_type=[couponDetail objectForKey:@"coupon_type"];
            int c_type = [coupon_type intValue];
            if(c_type == 1)
            {
                [self callServiceForCouponTypeOneBlock:[couponDetail objectForKey:@"id"] ];
                break;
            }
            else if(c_type == 2)
            {
                BusinessViewController *businessVC = [[BusinessViewController       alloc]initWithNibName:@"BusinessViewController" bundle:nil];
                [businessVC setCouponListDetail:couponDetail];
                [self.navigationController pushViewController:businessVC animated:YES];
                break;
            }
        }
    }

Answer 1

问题在于这一行：

[_delegate performSelector:@selector(mapView:didClickPinButton:)withObject:titleStr];

performSelector:withObject:方法只能用于调用一个对象参数的方法，但您的mapView:didClickPinButton:方法两个对象参数。

您可以而是使用performSelector:withObject:withObject:，它允许您使用两个对象参数调用方法，如下所示：

[_delegate performSelector:@selector(mapView:didClickPinButton:) 
    withObject:mapView withObject:titleStr];

但是，在这里使用performSelector似乎并不是必需的。

直接在委托上调用方法会更容易也更简单，因此方法有多少参数无关紧要：

[_delegate mapView:mapView didClickPinButton:titleStr];

单击地图引脚以获取详细视图，即可获得EXC_BAD_ACCESS

1 个答案: