objective-c - Objective-C : "Property implementation must have its declaration in interface"

Question

我有以下代码:

//RootViewController.h:

#import <UIKit/UIKit.h>

@interface RootViewController : UIViewController{
    IBOutlet UITextField *login_uname;
    IBOutlet UITextField *login_pword;
    IBOutlet UIActivityIndicatorView *login_thinger;
    IBOutlet UIImageView *logo;
    IBOutlet UISwitch *login_remember;

    IBOutlet UIScrollView *scrollView;
}




-(IBAction) login_submitClick:(id)sender;
-(IBAction) doneEditing:(id)sender;
-(IBAction) clearPword:(id)sender;
-(void) showSignUp:(id)sender;

-(void)doLogout:(id)sender;

//for file handling:
-(NSString *)documentsPath;
-(NSString *)readFromFile:(NSString *)filePath;
-(void) writeToFile:(NSString *)text withFileName:(NSString *) filePath;

@end

//RootViewController.m

#import "RootViewController.h"
//#import "Main.h"
//#import "SignUp.h"
#import "ASIHTTPRequest.h"
#import "ASIFormDataRequest.h"
#import "CommonCrypto/CommonHMAC.h"
#import "Details.h"
//#import "signUpSMS.h"
#import "JSON.h"

@implementation PrestoCab3ViewController
@synthesize login_uname;   //this line throws the error in the title

...

我正在使用 XCode 4.1，想知道是否有人可以帮助我弄清这个错误的根源。我是 XCode 的新手。

非常感谢，

Answer 1

您需要在您的接口(interface)中使用@property 声明该属性。

@property( nonatomic, retain ) IBOutlet UITextField * login_uname;

这里使用了非原子，因为它是一个 IBOutlet。另请注意，该属性具有保留修饰符，这意味着您有责任在不再需要该对象时释放该对象。