ios - 从不兼容类型 'id _Nullable' 分配给 'WebView *const __strong'

Question

当我在以下代码中将 webView.delegate = self; 添加到 WebView 时

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
    webView = [[UIWebView alloc] initWithFrame:CGRectMake(0, 0, [[UIScreen mainScreen] bounds].size.width, [[UIScreen mainScreen] bounds].size.height-64)];
    NSString *htmlFile = [[NSUserDefaults standardUserDefaults] objectForKey:USER_CODE];
     NSLog(@"Value retured : %@",htmlFile);
    NSURL *url = [NSURL URLWithString:htmlFile];
    webView.delegate = self;
    [webView loadRequest:[NSURLRequest requestWithURL:url]];
    [self.view addSubview:webView];
}

我收到以下错误。

/Applications/MAMP/htdocs/iOS/SchoolApp/test/WebView/WebView.m:25:22: Assigning to 'id<UIWebViewDelegate> _Nullable' from incompatible type 'WebView *const __strong'

Answer 1

您的 View Controller 没有实现 UIWebViewDelegate 协议(protocol)。不要在您的类的接口(interface)声明中包含它

@interface YourViewControllerName : UIViewController <UIWebViewDelegate>