可以通过编程方式填充UIWebView Web表单吗？

import UIKit
import WebKit

class ViewController: UIViewController, UIWebViewDelegate {
    
    @IBOutlet weak var webView: UIWebView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 设置UIWebView的代理
        webView.delegate = self
        
        // 加载Web页面
        let url = URL(string: "https://example.com/form.html")
        let request = URLRequest(url: url!)
        webView.loadRequest(request)
    }
    
    func webViewDidFinishLoad(_ webView: UIWebView) {
        // 填充表单元素的值
        let script = "document.getElementById('username').value = 'John'; document.getElementById('password').value = '123456';"
        webView.stringByEvaluatingJavaScript(from: script)
    }
}