在 Android (Kotlin) 上使用 Chaquopy 在 Python 中运行 Quart Web 服务器

Question

我正在尝试使用 Chaquopy 制作一个 Android 应用程序，其中包含在 Python 上运行的 Quart 应用程序，但是一旦我从 Python 添加对 Kotlin 的调用，我就会从 MainActivity 获得

Error starting Python server: Can't create handler inside thread Thread[Thread-4,5,main] that has not called Looper.prepare()

。所以我添加了对 Looper 的调用，但这给了我

Error starting Python server: Method addObserver must be called on the main thread

，即使运行 Quart 应用程序的调用是在启动 Python 解释器的线程中。

科特林：

package com.example.chatterbot

import android.annotation.SuppressLint
import android.net.http.SslError
import android.os.Bundle
import android.os.Looper
import android.util.Log
import android.webkit.SslErrorHandler
import android.webkit.WebView
import android.webkit.WebViewClient
import androidx.appcompat.app.AppCompatActivity
import androidx.swiperefreshlayout.widget.SwipeRefreshLayout
import com.chaquo.python.Python
import com.chaquo.python.android.AndroidPlatform

class MainActivity : AppCompatActivity() {

    private val tag: String = "MainActivity" // Define a tag for your logs
    private var serverPort: Int? = null
    private lateinit var webView: WebView
    private lateinit var swipeRefreshLayout: SwipeRefreshLayout

    @SuppressLint("SetJavaScriptEnabled")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Run the Python server in a background thread
        Thread {
            Looper.prepare()
            Log.i(tag, "Starting server")
            Log.i(tag, "IS STARTED")
            Log.i(tag, Python.isStarted().toString())
            if (! Python.isStarted()) {
                Python.start(AndroidPlatform(this))
            }
            try {
                val py = Python.getInstance()
                py.getModule("app").callAttr("run")
            } catch (e: Exception) {
                Log.e(tag, "Error starting Python server: ${e.message}")
            }
            Looper.loop()
        }.start()

        // Set webview
        Log.i(tag, "Starting webview")
        webView = findViewById(R.id.webview)
        webView.webViewClient = object : WebViewClient() {
            override fun onReceivedSslError(
                view: WebView?,
                handler: SslErrorHandler?,
                error: SslError?
            ) {
                // Ignore SSL certificate errors (not recommended for production)
                handler?.proceed()
            }
        }
        webView.settings.javaScriptEnabled = true
        webView.loadUrl("file:///android_asset/iframe/iframe.html")
        swipeRefreshLayout = findViewById(R.id.swipe_refresh_layout)
        swipeRefreshLayout.setOnRefreshListener {
            webView.reload() // Reload the current page
            swipeRefreshLayout.isRefreshing = false // Stop the refreshing animation
        }
    }

    fun closeLoader() {
        Log.i(tag, "Close loader")
        webView.evaluateJavascript("closeLoader();", null)
    }

}

Python：

from hypercorn.asyncio import serve
from hypercorn.config import Config
from quart import Quart, render_template
from com.example.chatterbot import MainActivity

activity = MainActivity() # <-- **The problem comes when i add this**

app = Quart(__name__)

config = Config()
config.bind = [f"0.0.0.0:8000"]
config.debug = True

@app.route('/')
async def index():
    return await render_template('index.html')

@app.after_serving
async def after_startup():
    # This code will run after the server is fully loaded and ready to receive requests
    print("Server ready")
    activity.closeLoader()

def run():
    app.run(host="0.0.0.0", port=8000, debug=True)

Answer 1

正如评论中所说，解决方案是这里。