Android：在 Volley 不工作的情况下发送一个简单的请求

Question

I think this is a stupid question, but I really do not know what went wrong with my simple app (I am a Android newbie btw).

Even this "easy" example is not working for me (thats frustrating!)

https://developer.android.com/training/volley/simple

I always get the message "That didn't work!".

My code is.

class MainActivity : AppCompatActivity() {

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

        val textView = findViewById<TextView>(R.id.text)

        val queue = Volley.newRequestQueue(this)
        val url = "http://www.apple.com"

        // Request a string response from the provided URL.
        val stringRequest = StringRequest(Request.Method.GET, url, Response.Listener<String> { response ->
                // Display the first 500 characters of the response string.
                textView.text = "Response is: ${response.substring(0, 500)}"
            },
            Response.ErrorListener { textView.text = "That didn't work!" })

        // Add the request to the RequestQueue.
        queue.add(stringRequest)

    }

}

I develop with Android Studio and a Virtual Device on a Mac Book.

Any suggestions?

Answer 1

Looks like your code is OK so maybe your app is missing Internet permissions, which is of course mandatory for HTTP requests.

Please add this to your AndroidManifest.xml :

<uses-permission android:name="android.permission.INTERNET"/>

Answer 2

我知道这已经很晚了，但我认为，在我尝试使用 HTTPS 而不是 HTTP 之前，我遇到了同样的问题。