ios - webview 在 objective-c 中不起作用

Question

我正在尝试根据我的数据库的内容加载一系列 url，即:http://www.whatever.com但是当我在模拟器中运行应用程序时什么也没有出现，我的代码如下所示

.h 文件(不包括导入语句)

@interface FSFourthScreenViewController : UIViewController

//insert code to create web view
{
    NSString * urlString;
    UIWebView * FSWebView;
}

// properties
@property (nonatomic, retain) NSString * urlString;
@property (nonatomic, retain) IBOutlet UIWebView * FSWebView;

@end

排除.m文件导入语句

@interface FSFourthScreenViewController ()

@end

@implementation FSFourthScreenViewController

@synthesize FSWebView, urlString;

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

- (void)viewDidLoad
{
    [super viewDidLoad];

    //background image
    self.view.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"backgroundimage.png"]];

    NSURL * url = [NSURL URLWithString:urlString];
    NSURLRequest * requestObj = [NSURLRequest requestWithURL:url];
    [FSWebView loadRequest:requestObj];

}


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

@end

我已正确连接 WebView ，并在数据库中分配了正确的字段。我还清理了 xCode 和模拟器，但仍然没有快乐......欢迎任何想法？

Answer 1

添加这段代码，检查你的对象:

  - (void)viewDidLoad
    {
        [super viewDidLoad];

        //background image
        self.view.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"backgroundimage.png"]];

        NSURL * url = [NSURL URLWithString:urlString];

        if (!url)
        {
            NSLog(@"url is nil!!!");
        }


        NSURLRequest * requestObj = [NSURLRequest requestWithURL:url];

        if (!FSWebView)
        {
            NSLog(@"RSWebView is nil!!!");
        }

        [FSWebView loadRequest:requestObj];

    }

我猜 url 是 nil ，或者 webview 是 nil