我如何保持当前页面直到下一页完全加载（iOS UIWebview）

Question

I have an app based on UIWebview , When a user clicks on a URL, the default behavior is to immediately show a blank page and stay waiting until the page is loaded

Is that possible to keep the current page until the next page is loaded?

Thanks for advance.

Answer 1

I'm curious as to the necessity for this funtionality and I'd probably agree with Chandra Vaghasiya 's comment .

Having said that this is possible.

1. Make your view controller the delegate of the UIWebView .
2. In the webViewDidStartLoad: method, take a snapshot of the web view and add the resulting view above the web view in the view hierarchy.
3. In the webViewDidFinishLoad: and webView:didFailLoadWithError: methods simply hide the snapshotted view.

Example code:

@interface ViewController () <UIWebViewDelegate>
@property (weak, nonatomic) IBOutlet UIWebView *webView;
@property (nonatomic, strong) UIView *snapshotView;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    NSURL *url = [NSURL URLWithString:@"https://google.com"];
    NSURLRequest *request = [NSURLRequest requestWithURL:url];
    [self.webView loadRequest:request];
}

- (void)webViewDidStartLoad:(UIWebView *)webView {
    self.snapshotView = [self.webView snapshotViewAfterScreenUpdates:NO];

    self.snapshotView.frame = self.webView.frame;

    [self.view insertSubview:self.snapshotView
                aboveSubview:self.webView];

    self.snapshotView.hidden = NO;

    // THIS IS JUST FOR DEMONSTRATION PURPOSES SO
    // YOU CAN SEE THE LOADING HAPPENING BEHIND
    // THE SNAPSHOT VIEW
    self.snapshotView.alpha = 0.8;

    NSLog(@"Display snapshot");
}

- (void)webViewDidFinishLoad:(UIWebView *)webView {
    self.snapshotView.hidden = YES;
    NSLog(@"Hide snapshot");
}

- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error {
    self.snapshotView.hidden = YES;
    NSLog(@"Hide snapshot due to error");
}

@end