试图用委托通过点击取消来解散一个视图控制器(根本不起作用)

Question

在一个导航控制器中有两个视图控制器:

PhoneNumbersTVC>保存NewPhoneNumberTVC添加的电话号码列表NewPhoneNumberTVC>电话号码添加控制器

当我点击取消NewPhoneNumberTVC时，我喜欢用下面的委托返回PhoneNumbersTVC。

PhoneNumbersTVC.h

#import <UIKit/UIKit.h>
#import "NewPhoneNumberTVC.h"
@interface PhoneNumbersTVC : UITableViewController <NewPhoneNumberTVCDelegate>
@end

PhoneNumbersTVC.m

- (void)saveBtnWasTappedOnNewPhoneNumberTVC:(NewPhoneNumberTVC *)newPhoneNumberTVC
{
    NSLog(@"saveBtnWasTappedOnNewPhoneNumberTVC");
    [newPhoneNumberTVC.navigationController popViewControllerAnimated:YES];
}
- (void)cancelBtnWasTappedOnNewPhoneNumberTVC:(NewPhoneNumberTVC *)newPhoneNumberTVC
{
    NSLog(@"cancelBtnWasTappedOnNewPhoneNumberTVC");
    [newPhoneNumberTVC.navigationController popViewControllerAnimated:YES];
}

NewPhoneNumberTVC.h

#import <UIKit/UIKit.h>
@class NewPhoneNumberTVC;
@protocol NewPhoneNumberTVCDelegate <NSObject>
- (void)saveBtnWasTappedOnNewPhoneNumberTVC:(NewPhoneNumberTVC *)newPhoneNumberTVC;
- (void)cancelBtnWasTappedOnNewPhoneNumberTVC:(NewPhoneNumberTVC *)newPhoneNumberTVC;
@end

@interface NewPhoneNumberTVC : UITableViewController
@property (weak, nonatomic) id <NewPhoneNumberTVCDelegate> delegate;
@property (strong, nonatomic) NSManagedObjectContext *managedOC;
@property (weak, nonatomic) IBOutlet UITextField *phoneNumberTextField;
- (IBAction)saveBtnTapped:(UIBarButtonItem *)sender;
- (IBAction)cancelBtnTapped:(UIBarButtonItem *)sender;
@end

NewPhoneNumberTVC.m

- (IBAction)cancelBtnTapped:(UIBarButtonItem *)sender
{
    NSLog(@"cancelBtnTapped");
    self.phoneNumberTextField.text = @"";
    self.phoneKindTextField.text = @"";
    [self.delegate cancelBtnWasTappedOnNewPhoneNumberTVC:self];

}

当我在NewPhoneNumberTVC上点击取消时，我看到上面的方法cancelBtnTapped触发，但delegation不起作用，没有method在PhoneNumbersTVC中执行。视图没有消失，我没有看到:cancelBtnWasTappedOnNewPhoneNumberTVC在console上

Answer 1

如果你想要这个方法cancelBtnWasTappedOnNewPhoneNumberTVC:被调用，你肯定需要将你的NewPhoneNumberTVC对象的委托设置为PhoneNumbersTVC对象。例如，PhoneNumbersTVC中应该存在一些代码。m :

NewPhoneNumberTVC *myNewPhoneNumberTVC = [[NewPhoneNumberTVC alloc] init];
myNewPhoneNumberTVC.delegate = self;

您可以按照以下方式进行日志记录，以验证委托是否成功设置"

NewPhoneNumberTVC.m

- (IBAction)cancelBtnTapped:(UIBarButtonItem *)sender
{
NSLog(@"cancelBtnTapped");
self.phoneNumberTextField.text = @"";
self.phoneKindTextField.text = @"";
NSLog(@"self.delegate :%@",self.delegate);
[self.delegate cancelBtnWasTappedOnNewPhoneNumberTVC:self];
}