h5页面使用了alert()方法，但是在iOS app上不显示弹窗，解决办法如下：
首先要设置代理WKUIDelegate，然后加入下面的代码
#pragma mark - WKWebView UIDelegate - (void)webView:(WKWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(void))completionHandler { UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"提示" message:message?:@"" preferredStyle:UIAlertControllerStyleAlert]; [alertController addAction:([UIAlertAction actionWithTitle:@"确认" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) { completionHandler(); }])]; [self presentViewController:alertController animated:YES completion:nil]; } // 显示两个按钮，通过completionHandler回调判断客户点击确实定还是取消按钮 - (void)webView:(WKWebView *)webView runJavaScriptConfirmPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(BOOL))completionHandler { UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"提示" message:message?:@"" preferredStyle:UIAlertControllerStyleAlert]; [alertController addAction:([UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) { completionHandler(NO); }])]; [alertController addAction:([UIAlertAction actionWithTitle:@"确认" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) { completionHandler(YES); }])]; [self presentViewController:alertController animated:YES completion:nil]; } // 显示一个带有输入框和一个确定按钮的，通过completionHandler回调客户输入的内容 - (void)webView:(WKWebView *)webView runJavaScriptTextInputPanelWithPrompt:(NSString *)prompt defaultText:(NSString *)defaultText initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(NSString * _Nullable))completionHandler { UIAlertController *alertController = [UIAlertController alertControllerWithTitle:prompt message:@"" preferredStyle:UIAlertControllerStyleAlert]; [alertController addTextFieldWithConfigurationHandler:^(UITextField * _Nonnull textField) { textField.text = defaultText; }]; [alertController addAction:([UIAlertAction actionWithTitle:@"完成" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) { completionHandler(alertController.textFields[0].text?:@""); }])]; [self presentViewController:alertController animated:YES completion:nil]; }
