ios uiviewcontroller继承抛出重复的符号错误

Question

我有一个父视图控制器，它有一个我希望所有子类可用的方法：

#import "GAViewController.h"

@interface GAViewController ()<UITextFieldDelegate>

@end

@implementation GAViewController


#pragma mark - UITextFieldDelegate

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


@end

我有一个寄存器视图控制器，如下所示：

//.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

以下是我收到的错误：

有谁知道我可以解决上面的错误吗？或者使用textFieldShoudlReturn方法正确创建父类，这样我就不必包含在我的所有视图中。

谢谢！

Answer 1

  

我正在导入.m，因为它包含textfieldshouldreturn方法，它还会导入.h文件

导入.m文件会导致重复的符号。导入.m文件会导致导入它的文件定义相同的符号（例如方法实现和带外部作用域的函数/变量）作为包含的.m文件，从而导致重复。

出于同样的原因，不应该将@implementation块放入头文件中。

要解决此问题，请为GAViewController制作标题，并在其中声明textFieldShouldReturn:。从标头和.m文件中删除#import "GAViewController.m"，替换为#import "GAViewController.h"。这应该可以解决问题。