我正在嘗試將遠(yuǎn)程 URL 中的字符串分配給變量。當(dāng)我在運行遠(yuǎn)程 URL 代碼后檢查該變量時，它是空的。首先我聲明了空字符串，然后從 URL 中獲取字符串并嘗試將其分配給變量。字符串被提取但未分配給變量。下面是代碼public class MainActivity extends Activity {static String channel_uri = "";@Overrideprotected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    new DownloadWebPageTask().execute();    if(channel_uri.isEmpty()){        Log.i("channel_text", "Empty");    }}private static class DownloadWebPageTask extends AsyncTask<String, Void, String> {    @Override    protected String doInBackground(String... params) {        final OkHttpClient client = new OkHttpClient();        Request request = new Request.Builder()                .url("http://yeshuaatv.com/channel/streamingurl/adaptive.txt")                .build();        Response response = null;        try {            response = client.newCall(request).execute();            if (!response.isSuccessful())                throw new IOException("Unexpected code " + response);            Headers responseHeaders = response.headers();            channel_uri = response.body().string();            return channel_uri;        } catch (IOException e) {            e.printStackTrace();        }        return null;    }    @Override    protected void onPostExecute(String s) {        //tvdata.setText(channel);        // you will get data in url string        super.onPostExecute(s);    }}}