安卓错误:方法gettext必须从当前推断的线程正在工作的UI线程调用

Question

大家好，我是Android的新手，我正在构建一个英语到德语的翻译应用程序，我因遵循代码行而收到上述错误：可以协助我如何解决此问题。

package com.exmaple.android.lang_trans;
import java.util.Locale;
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.speech.tts.TextToSpeech;
import android.speech.tts.TextToSpeech.OnInitListener;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import com.exmaple.android.lang_trans.R;
import com.memetix.mst.language.Language;
import com.memetix.mst.translate.Translate;
public class MainActivity extends Activity implements OnInitListener {
    private TextToSpeech tts;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tts = new TextToSpeech(this, this);
        ((Button) findViewById(R.id.bSpeak)).setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                speakOut(((TextView) findViewById(R.id.tvTranslatedText)).getText().toString());
            }
        });
        ((Button) findViewById(R.id.bTranslate)).setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub

                class bgStuff extends AsyncTask<Void, Void, Void> {
                    String translatedText = "";
                    @Override
                    protected Void doInBackground(Void... params) {
                        // TODO Auto-generated method stub
                        try {
                            //below line is throwing the error
                            String text = ((EditText) findViewById(R.id.etUserText)).getText().toString();
                            translatedText = translate(text);
                        } catch (Exception e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                            translatedText = e.toString();
                        }
                        return null;
                    }
                    @Override
                    protected void onPostExecute(Void result) {
                        // TODO Auto-generated method stub
                        ((TextView) findViewById(R.id.tvTranslatedText)).setText(translatedText);
                        super.onPostExecute(result);
                    }
                }
                new bgStuff().execute();
            }
        });
    }
    public String translate(String text) throws Exception {

        // Set the Client ID / Client Secret once per JVM. It is set statically and applies to all services
        Translate.setClientId("CLIENT ID"); //Change this
        Translate.setClientSecret("CLIENT SECRET"); //change

        String translatedText = "";
        translatedText = Translate.execute(text, Language.GERMAN);
        return translatedText;
    }
    @Override
    public void onInit(int status) {
        // TODO Auto-generated method stub
        if (status == TextToSpeech.SUCCESS) {
            int result = tts.setLanguage(Locale.GERMAN);
            if (result == TextToSpeech.LANG_MISSING_DATA
                    || result == TextToSpeech.LANG_NOT_SUPPORTED) {
                Log.e("TTS", "This Language is not supported");
            } else {
                //speakOut("Ich");
            }
        } else {
            Log.e("TTS", "Initilization Failed!");
        }
    }
    private void speakOut(String text) {
        tts.speak(text, TextToSpeech.QUEUE_FLUSH, null);
    }
}

Answer 1

您的问题是您在 android 系统不允许的 UI 线程以外的线程中访问您的 UI 元素

不能从 UI 线程或"主"线程以外的任何线程更新 UI。

https://developer.android.com/guide/components/processes-and-threads.html#WorkerThreads

因此，您可以将onClick函数更改为以下内容：

((Button) findViewById(R.id.bTranslate)).setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View v) {
        class bgStuff extends AsyncTask<String, Void, String> {
            @Override
            protected String doInBackground(String... params) {
                // TODO Auto-generated method stub
                try {
                    if (params.length > 0) {
                        return translate(params[0]);
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                    return e.toString();
                }
                return null;
            }
            @Override
            protected void onPostExecute(String result) {
                ((TextView) findViewById(R.id.tvTranslatedText)).setText(result);
            }
        }
        new bgStuff().execute(((EditText) findViewById(R.id.etUserText)).getText().toString());
    }
});