Ios 如何在WKWebView Swift中提交表单？

我一直在尝试使用

WKWebView

来填写一个网络表单并提交。到目前为止，我已经能够做到这一点。问题是

WebView

表单循环从“insert element”，尝试提交“到“submited”，直到我使用下面的代码

let submitFunction = document.forms[0].submit();

有人知道发生了什么吗？我如何重写这段代码

多谢各位

import UIKit
import WebKit
class AnswerVC: UIViewController {

@IBOutlet weak var webView: WKWebView!

var questionText = "1+1"

override func viewDidLoad() {
    super.viewDidLoad()
    webView.navigationDelegate = self
}

override func viewWillAppear(_ animated: Bool) {
    let url:URL = URL(string: "https://gamma.sympy.org/")!
    let urlRequest:URLRequest = URLRequest(url: url)
    webView.load(urlRequest)
}
}

---

extension AnswerVC: WKNavigationDelegate {

func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {

    print("insert element")

    let scriptFunction = "document.getElementById('id_i').value = '\(questionText)';"
    webView.evaluateJavaScript(scriptFunction) { (result, error) in

        if error != nil {

            ProgressHUD.showError(error as? String)

        } else {

            print("trying to submit")
            let submitFunction = "document.forms[0].submit();"
            webView.evaluateJavaScript(submitFunction) { (result, error) in
                if error != nil {
                    print(error?.localizedDescription)

                } else {
                    print("submited")
                }
            }
        }
    }

}
}