Question

我正在尝试在City.m控制器中创建的AddCity.m控制器中使用委托方法。方法是

City.m

    - (void)EditCityController:(id)controller didEditItem:(id)item
{
    if(item)
    {
        NSDictionary *d = (NSDictionary *)item;
        [self.model addNewCity:[d valueForKey:@"cityName"] forProvince:self.ro inMayor:[d valueForKey:@"mayorName"] inPopulation:[[d valueForKey:@"population"]intValue] inYearEstablished:[[d valueForKey:@"yearEstablished"]intValue]];
        [self.model saveChanges];

    }

    // Dismiss the modal view controller
    [controller dismissViewControllerAnimated:YES completion:nil];
}

City.h

    @interface Cities : 
UITableViewController<NSFetchedResultsControllerDelegate, EditCityDelegate>

然后在AddCity.h中我有

    @protocol EditCityDelegate;

@interface AddCity : UIViewController<UITextFieldDelegate>

@property (nonatomic, assign) id <EditCityDelegate> delegate;

@protocol EditCityDelegate <NSObject>

- (void) EditCityController:(id)controller didEditItem:(id)item;

@end

我从AddCity.m调用它（目前正在尝试取消按钮）。

- (IBAction)cancel:(id)sender {
    [self.delegate EditCityController:self didEditItem:nil];
}

当我设置一个断点时会发生什么事情，它会击中self.delegate行，但它不会进入City.m控制器中的EditCityController方法。任何关于我做错的想法？

Answer 1

我假设您在City.m中调用AddCity.m并使用presentViewController

显示它

AddCity *addcityVC = [AddCity new];
addcityVC.delegate = self; // initialize the delegate here
[self presentViewController:addCityVC animated:YES completion:nil];

您需要将委托初始化为self，以便它可以调用您需要的方法

希望这有帮助

我的程序没有进入委托方法

1 个答案: