从一个 VC 到另一个 VC 但在那之后一切都挂了

Question

您好，我设法使用以下代码从TopVC 转到BottomVC。但在那之后我的bottomVC 将无法工作。点击链接时BottomVC 不会前进。

编辑的答案

Top VC 我用下面的代码去bottomVC，我到底是去BottomVC还是BottomClass？

    UIStoryboard *sb = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
    UIViewController *vc = [sb instantiateViewControllerWithIdentifier:@"BuyCredit"];
    vc.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
    [[self navigationController] pushViewController:vc animated:YES];

    UINavigationController* classesNav = (UINavigationController*)self.tabBarController.viewControllers[4];
    BuyCredit *classesViewController = [classesNav.viewControllers firstObject];
    [classesViewController fromClassBook:sURL];

底部 VC 假设在单击链接时加载另一个 VC，但一切都挂起

- (void)viewDidLoad {

    [super viewDidLoad];

    sURL = self.urlString;

    NSLog(@"Receiving From and the sURL :  %@", sURL);

    NSURL *url = [NSURL URLWithString:sURL];
    NSURLRequest *urlRequest = [NSURLRequest requestWithURL:url];
    [webView setDelegate:(id<UIWebViewDelegate>)self];
    [webView loadRequest:urlRequest];

}

- (void)fromClassBook:(NSString*)string {

    sURL = string;
    NSLog(@"Please pass over **** %@", sURL);

    NSURL *url = [NSURL URLWithString:sURL];
    NSURLRequest *urlRequest = [NSURLRequest requestWithURL:url];
    [webView setDelegate:(id<UIWebViewDelegate>)self];
    [webView loadRequest:urlRequest];

}


- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {

    PurchaseDet *target = segue.destinationViewController;

    if ([segue.identifier isEqualToString:@"PurchaseDet"]) {

        target.urlString = sURL;

    } 
}


- (BOOL)webView:(UIWebView*)webView shouldStartLoadWithRequest:(NSURLRequest*)request navigationType:(UIWebViewNavigationType)navigationType {

    NSURL *URL = [request URL];
    NSString *theString = [URL absoluteString];
    NSRange match;

    NSLog(@"Detect the URL theString :  %@", theString);

    match = [theString rangeOfString: @"PHPSMI"];

    //--- If the URL string does not contain purchase_det.asp meaning it will load the webview
    if (match.location == NSNotFound) {
        sURL = theString;
        return YES; //--- Load webview

    } else {  //--- Because currently the purchase confirm page is just another page, hence will reload the current webview.

        NSLog(@"Will pass to SEQUE and called the URL :%@",theString);
        //--- Calling this method will tell the segue hey I want to redirect to another viewController.
        //--- Update the sURL with the latest String
        sURL = theString;

        [self performSegueWithIdentifier:@"PurchaseDet" sender:self];

        return NO; // Don't load the webview, capture the sURL and trigger NewsDet segue, and then pass sURL as urlstring to destination VC
    }

}
@end

Answer 1

替换

[self presentViewController:vc animated:YES completion:NULL];

有

[[self navigationController] pushViewController:vc animated:YES];

注意：- 您只在 TopVC 上呈现 bottomVC。因此 rootViewController 仍然是 TopVC。因此，当您调用 performSegueWithIdentifier 时，它会为 bottomVC 获取 nil 对象。

试试这个..