ios uiviewcontroller继承抛出重复符号错误

Question

我有一个父 View Controller ，它有一个我希望所有子类都可以使用的方法:

#import "GAViewController.h"

@interface GAViewController ()<UITextFieldDelegate>

@end

@implementation GAViewController


#pragma mark - UITextFieldDelegate

- (BOOL)textFieldShouldReturn:(UITextField *)textField
{
    [textField resignFirstResponder];
    return YES;
}


@end

我有一个看起来像这样的注册 View Controller :

//.h
    #import <UIKit/UIKit.h>
    #import "GAViewController.h"
    #import "GAViewController.m"

    @interface GARegisterViewController : GAViewController

    @end

//.m
#import "GARegisterViewController.h"


@interface GARegisterViewController ()<UIActionSheetDelegate, UINavigationControllerDelegate, UIImagePickerControllerDelegate, UIGestureRecognizerDelegate>
@property (weak, nonatomic) IBOutlet UIButton *registerButton;
@property (weak, nonatomic) IBOutlet UITextField *userNameTextField;
@property (weak, nonatomic) IBOutlet UITextField *passwordTextField;
@property (weak, nonatomic) IBOutlet UITextField *firstNameTextField;
@property (weak, nonatomic) IBOutlet UITextField *lastNameTextField;
@property (weak, nonatomic) IBOutlet UITextField *phoneNumberTextField;
@property (weak, nonatomic) IBOutlet UISegmentedControl *genderSegmentedContoller;

@end

@implementation GARegisterViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    [self makeTextFieldDelegates];
}

- (void)makeTextFieldDelegates{
    [self.userNameTextField setDelegate:self];
    [self.passwordTextField setDelegate:self];
    [self.firstNameTextField setDelegate:self];
    [self.lastNameTextField setDelegate:self];
    [self.phoneNumberTextField setDelegate:self];
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

这是我收到的错误:



有谁知道我可以修复上面的错误？或者使用 textFieldShoudlReturn 正确创建父类方法，这样我就不必包含在我的所有观点中。

谢谢!

Answer 1

I am importing .m because it contains the textfieldshouldreturn method, it also imports the .h file

它正在导入导致重复符号的 .m 文件。导入 .m 文件会导致从中导入它的文件定义与包含的 .m 文件相同的符号(例如方法实现和具有外部范围的函数/变量)，从而导致重复。

出于同样的原因，永远不要放置 @implementation block 到头文件中。

为了解决这个问题，为 GAViewController 创建一个标题。 , 并声明 textFieldShouldReturn:在里面。删除 #import "GAViewController.m"从您的标题和 .m 文件中替换为 #import "GAViewController.h" .这应该可以解决问题。