解决H5微信支付返回跳转问题

注册域名坑：请使用www.xxx.com(别使用abc.m.en.com)这种形式向微信注册，否则无法正常回调处理

使用iOS打开微信支付页面需要设置webview的Referer
Referer一般为http://www.xxx.com或者直接www.xxx.com
在Info中URL Type添加该Referer为打开自己app的scheme
嗯，就这样结束！！！

现的是通过拦截web请求，判断是否为https/http请求，不是则通过scheme方式打开外部页面:标准写法

- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler {
    NSURL *url = navigationAction.request.URL;
    NSString *scheme = [url scheme];
    if (![scheme isEqualToString:@"https"] && ![scheme isEqualToString:@"http"]) {
        [[UIApplication sharedApplication] openURL:url];
    }
    decisionHandler(WKNavigationActionPolicyAllow);
}

打开微信可能遇到的坑

下方代码不但实现页面跳转，还处理了web url不是微信注册的refer问题

 - (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler {
    
    NSURLRequest *request = navigationAction.request;
    NSString *scheme = [request.URL scheme];
    //微信支付
    if ([scheme isEqualToString:@"weixin"]) {
        decisionHandler(WKNavigationActionPolicyCancel);
        BOOL canOpen = [[UIApplication sharedApplication] canOpenURL:request.URL];
        if (canOpen) {
            [[UIApplication sharedApplication] openURL:request.URL];
        }
        return;
    }
    
    NSDictionary *referDict = [[NSUserDefaults standardUserDefaults] objectForKey:@"loadUrlWithRefer"];
    if (referDict != nil && [referDict isKindOfClass:[NSDictionary class]]) {
         NSString *url = referDict[@"url"];
         NSString *refer = referDict[@"refer"];
         NSDictionary *headers = [navigationAction.request allHTTPHeaderFields];
         NSString * referer = [headers objectForKey:@"Referer"];
         BOOL isRightReferer = [referer isEqualToString:refer];
         if (isRightReferer) {
             decisionHandler(WKNavigationActionPolicyAllow);
         } else {
             decisionHandler(WKNavigationActionPolicyCancel);
             if ([url isEqualToString:[navigationAction.request.URL absoluteString]]) {
                 NSMutableDictionary * muDict = [[NSMutableDictionary alloc] initWithDictionary:headers];
                 [muDict setObject:refer forKey:@"Referer"];
                 dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
                     dispatch_async(dispatch_get_main_queue(), ^{
                         NSURL *url = [navigationAction.request URL];
                         NSMutableURLRequest* request = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestReloadIgnoringCacheData timeoutInterval:60.0];
                         request.allHTTPHeaderFields = muDict;
                         [webView loadRequest:request];
                     });
                 });
             }
             [[NSUserDefaults standardUserDefaults] removeObjectForKey:@"loadUrlWithRefer"];
             return;
         }
    }
    decisionHandler(WKNavigationActionPolicyAllow);
}

loadUrlWithRefer存储的内容为web页面请求的订单信息通过js传递到原生并存储，包括注册微信的url和refer

//微信支付
https://wxpay.wxutil.com/mch/pay/h5.v2.php