Question

我正在构建一个Android应用程序，以从Yandex翻译API获取翻译后的文本。我按照此one来构建翻译器，这是我的代码：

    import android.content.Context;
    import android.os.AsyncTask;
    import android.os.Bundle;
    import android.support.v7.app.AppCompatActivity;
    import android.util.Log;
    import android.view.View;
    import android.widget.Button;
    import android.widget.EditText;
    import android.widget.TextView;
    import android.widget.Toast;

    import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.InputStreamReader;
    import java.net.HttpURLConnection;
    import java.net.MalformedURLException;
    import java.net.URL;


    public class TranslateActivity extends AppCompatActivity {


        String txtIn = null, txtOut = null;
        EditText mInput;
        Button mButton;
        TextView mOutput;
        Context mContext;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_translate);

            mInput = findViewById(R.id.source);
            mButton = findViewById(R.id.btn_switch);
            mOutput = findViewById(R.id.translated);

            txtIn = mInput.getText().toString();


            mButton.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    try {
                        Translate(txtIn, "en-vi");
                    } catch (Exception e) {
                        Toast.makeText(getApplicationContext(), e.toString(), Toast.LENGTH_SHORT).show();
                        Log.e("fail", e.toString());
                    }
                }
            });
        }

        void Translate(String textToBeTranslate, String langugePair) {
            Translator translator = new Translator(mContext);
            String translationResult = translator.execute(textToBeTranslate, langugePair); //error at this line
            mOutput.setText(translationResult);
        }

        public class Translator extends AsyncTask<String, Void, String> {
            Context ctx;

            Translator(Context ctx) {
                this.ctx = ctx;
            }


            @Override
            protected String doInBackground(String... params) {
                String textToBeTranslated = params[0];
                String languagePair = params[1];

                String jsonString;

                try {
                    String yandexKey = "trnsl.1.1.20190315T190036Z.47a8fe872fd33ab2.bde24d4d7a5ab1573adbe90b2413b459bdeb9ed4";
                    String yandexUrl = "https://translate.yandex.net/api/v1.5/tr.json/translate?key=" + yandexKey
                            + "&text=" + textToBeTranslated + "&lang=" + languagePair;
                    URL yandexTranslateURL = new URL(yandexUrl);

                    HttpURLConnection httpJsonConnection = (HttpURLConnection) yandexTranslateURL.openConnection();
                    InputStream inputStream = httpJsonConnection.getInputStream();
                    BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));

                    StringBuilder jsonStringBuilder = new StringBuilder();
                    while ((jsonString = bufferedReader.readLine()) != null) {
                        jsonStringBuilder.append(jsonString + "\n");
                    }

                    bufferedReader.close();
                    inputStream.close();
                    httpJsonConnection.disconnect();

                    String resultString = jsonStringBuilder.toString().trim();

                    resultString = resultString.substring(resultString.indexOf('[') + 1);
                    resultString = resultString.substring(0, resultString.indexOf("]"));

                    resultString = resultString.substring(resultString.indexOf("\"") + 1);
                    resultString = resultString.substring(0, resultString.indexOf("\""));

                    Log.d("Translate Result:", resultString);
                    return jsonStringBuilder.toString().trim();

                } catch (MalformedURLException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                return null;

            }

            @Override
            protected void onPreExecute() {
                super.onPreExecute();
            }

            @Override
            protected void onPostExecute(String s) {

            }

            @Override
            protected void onProgressUpdate(Void... values) {
                super.onProgressUpdate(values);
            }
        }


    }

但是它返回错误：

错误：类型不兼容：AsyncTask无法转换为字符串

我检查了所有与示例代码相同的内容，但不知道为什么。

Answer 1

因为您的代码不正确，所以您应该更改它。

TranslateActivity

void Translate(String textToBeTranslate, String langugePair) {
    Translator translator = new Translator(mContext);
    translator.execute(textToBeTranslate, langugePair);
}

翻译器

@Override
protected void onPostExecute(String translationResult) {
    mOutput.setText(translationResult);
}

无法在Android中执行AsyncTask

1 个答案: