React Native，如何在Webview中发布FormData

import React, { useState } from 'react';
import { View, WebView, Button } from 'react-native';

const formData = new FormData();
formData.append('username', 'John');
formData.append('password', '123456');

const [isLoading, setIsLoading] = useState(true);

const handleWebViewLoad = () => {
  setIsLoading(false);
};

const App = () => {
  const handleSubmit = () => {
    // 在Webview中执行表单提交操作
    webViewRef.current.injectJavaScript(`
      const form = document.createElement('form');
      form.method = 'POST';
      form.action = 'https://example.com/submit';
      form.enctype = 'multipart/form-data';
      
      const usernameInput = document.createElement('input');
      usernameInput.type = 'text';
      usernameInput.name = 'username';
      usernameInput.value = 'John';
      form.appendChild(usernameInput);
      
      const passwordInput = document.createElement('input');
      passwordInput.type = 'password';
      passwordInput.name = 'password';
      passwordInput.value = '123456';
      form.appendChild(passwordInput);
      
      document.body.appendChild(form);
      form.submit();
    `);
  };

  const webViewRef = useRef(null);

  return (
    <View style={{ flex: 1 }}>
      <WebView
        ref={webViewRef}
        source={{ uri: 'https://example.com/form' }}
        onLoad={handleWebViewLoad}
        style={{ flex: 1, opacity: isLoading ? 0 : 1 }}
      />
      {isLoading && <ActivityIndicator style={{ position: 'absolute', top: '50%', left: '50%' }} />}
      <Button title="Submit" onPress={handleSubmit} />
    </View>
  );
};

export default App;