预期标识符或（

Question

我正在使用网络浏览器应用程序，但目前我陷入错误：“预期的标识符或'（''，我不知道该怎么办。显示错误：

{:here is the error 
    NSURL *url = [NSURL URLWithString:urlString]; 
    NSURLRequest *urlRequest = [NSURLRequest requestWithURL:url]; 
    [self.webView loadRequest:urlRequest]; 
} 

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更新：

我不知道我应该什么其他的代码给你所以这里是在ViewController.m整个代码文件：

#import "ViewController.h" 

@interface ViewController() 
@property (weak, nonatomic) IBOutlet UIWebView *webView; 
@property (weak, nonatomic) IBOutlet UIBarButtonItem *back; 
@property (weak, nonatomic) IBOutlet UIBarButtonItem *refresh; 
@property (weak, nonatomic) IBOutlet UIBarButtonItem *stop; 
@property (weak, nonatomic) IBOutlet UIBarButtonItem *forward; 

- (void)loadRequestFromString:(NSString*)urlString; 

{ *HERE IS THE ERROR:EXPECTED IDENTIFIER OR '('* 
    NSURL *url = [NSURL URLWithString:urlString]; 
    NSURLRequest *urlRequest = [NSURLRequest requestWithURL:url]; 
    [self.webView loadRequest:urlRequest]; 
} 

@end 

@implementation ViewController ***HERE IS A WARNING SAYING:METHOD DEFINITION FOR 'LOADREQUESTFROMSTRING:'NOT FOUND*** 

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 
    // Do any `enter code here`additional setup after loading the view, typically from a nib. 
    [self loadRequestFromString:@"http://www.apple.com/startpage/"]; 
} 

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

@end 

Answer 1

为什么你要执行的代码在你的界面

@interface ViewController() 
@property (weak, nonatomic) IBOutlet UIWebView *webView; 
@property (weak, nonatomic) IBOutlet UIBarButtonItem *back; 
@property (weak, nonatomic) IBOutlet UIBarButtonItem *refresh; 
@property (weak, nonatomic) IBOutlet UIBarButtonItem *stop; 
@property (weak, nonatomic) IBOutlet UIBarButtonItem *forward; 

// This is a private interface and doesn't need the below line ever. 
// If you want this public then add it to the interface in the .h file. 
- (void)loadRequestFromString:(NSString*)urlString; 

***************************************************************************** 
// This is implementation code and shouldn't be here. 
// This belongs in the implementation not the interface 
{ *HERE IS THE ERROR:EXPECTED IDENTIFIER OR '('* 
    NSURL *url = [NSURL URLWithString:urlString]; 
    NSURLRequest *urlRequest = [NSURLRequest requestWithURL:url]; 
    [self.webView loadRequest:urlRequest]; 
} 
***************************************************************************** 
@end 

在您的实现@implementation添加

@implementation ViewController 
// Your other code such as viewDidLoad etc 

// Adding this method to the implementation will also get rid of the warning 
// ***HERE IS A WARNING SAYING:METHOD DEFINITION FOR 'LOADREQUESTFROMSTRING:'NOT FOUND*** 
// As it will now be implemented but there is no reason to declare the method in a private interface 
- (void)loadRequestFromString:(NSString*)urlString; 
{ 
    NSURL *url = [NSURL URLWithString:urlString]; 
    NSURLRequest *urlRequest = [NSURLRequest requestWithURL:url]; 
    [self.webView loadRequest:urlRequest]; 
} 

因为这是实现代码不应该在界面上。