Java 为什么我的android应用程序在启动时会崩溃

我刚刚开始学习制作android应用程序，我正在我的android studio上尝试这个语音识别应用程序。当我点击RUN时，emulator Api 29打开，显示一个空白页面，然后用CLOSE应用程序关闭！窗户。它在我的android手机Api 24上也做了同样的事情

我检查了所有可能导致您过去成员相关问题的原因，但没有找到类似的解决方案

public class MainActivity extends AppCompatActivity{

         private static final int MY_PERMISSIONS_RECORD_AUDIO = 1;   // MIC PERMISSION VARIABLE
        // private static final int REQUEST_RECORD_PERMISSION = 1;

          android.speech.tts.TextToSpeech TTS;   //variable del TextToSpeech
          SpeechRecognizer speechRecog;

         private android.widget.ProgressBar progressBar;
         private SpeechRecognizer speech = null;
         private android.content.Intent recognizerIntent;
         private String LOG_TAG = "VoiceRecognitionActivity";



    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //android.widget.TextView returnedText = (findViewById(R.id.textView1));
        progressBar = (findViewById(R.id.progressBar1));
        android.widget.ToggleButton toggleButton = (findViewById(R.id.toggleButton1));
        progressBar.setVisibility(android.view.View.INVISIBLE);


        final SpeechRecognizer speech = SpeechRecognizer
                .createSpeechRecognizer(MainActivity.this);


        android.util.Log.i(LOG_TAG, "isRecognitionAvailable: " + SpeechRecognizer.isRecognitionAvailable(this));

        speech.setRecognitionListener((android.speech.RecognitionListener) this);
        recognizerIntent = new android.content.Intent(android.speech.RecognizerIntent.ACTION_RECOGNIZE_SPEECH);
        recognizerIntent.putExtra(android.speech.RecognizerIntent.EXTRA_LANGUAGE_PREFERENCE,  "en");

        recognizerIntent.putExtra(android.speech.RecognizerIntent.EXTRA_LANGUAGE_MODEL,
                android.speech.RecognizerIntent.LANGUAGE_MODEL_FREE_FORM);
        recognizerIntent.putExtra(android.speech.RecognizerIntent.EXTRA_MAX_RESULTS, 3);

        toggleButton.setOnCheckedChangeListener(new android.widget.CompoundButton.OnCheckedChangeListener() {


            public void onCheckedChanged(android.widget.CompoundButton buttonView,
                                         boolean isChecked) {

                if (isChecked) {
                    progressBar.setVisibility(android.view.View.VISIBLE);
                    progressBar.setIndeterminate(true);

                } else {


                    progressBar.setIndeterminate(false);
                    progressBar.setVisibility(android.view.View.INVISIBLE);
                    speech.stopListening();
                }
            }
        });

这是一份日志

2019-07-11 14:58:46.703 32610-32610/com.example.speech_recognition E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.speech_recognition, PID: 32610
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.speech_recognition/com.example.speech_recognition.MainActivity}: java.lang.ClassCastException: com.example.speech_recognition.MainActivity cannot be cast to android.speech.RecognitionListener
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3260)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3396)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2009)
        at android.os.Handler.dispatchMessage(Handler.java:107)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7319)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:934)
     Caused by: java.lang.ClassCastException: com.example.speech_recognition.MainActivity cannot be cast to android.speech.RecognitionListener
        at com.example.speech_recognition.MainActivity.onCreate(MainActivity.java:51)
        at android.app.Activity.performCreate(Activity.java:7783)
        at android.app.Activity.performCreate(Activity.java:7772)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1299)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3235)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3396) 
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83) 
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) 
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2009) 
        at android.os.Handler.dispatchMessage(Handler.java:107) 
        at android.os.Looper.loop(Looper.java:214) 
        at android.app.ActivityThread.main(ActivityThread.java:7319) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:934) 
2019-07-11 14:58:46.739 32610-32610/com.example.speech_recognition I/Process: Sending signal. PID: 32610 SIG: 9

---

它在这方面是失败的：

speech.setRecognitionListener((android.speech.RecognitionListener) this);

---

问题是您的

main活动

没有实现接口，因此无法将其转换为该类型。

日志显示错误在第51行。你能强调一下这一点吗：

是由。。。在com.example.speech\u recognition.MainActivity.onCreate（MainActivity.java:51）

这是第51行：speech.setRecognitionListener（（android.speech.RecognitionListener）this）；那么，谢谢大卫回答我的问题。你刚才说的那句话已经出现在我的节目里了。我在复制粘贴时错过了它。对不起。David，我继续在我的android studio上运行调试器，发现程序在这一行speech.setRecognitionListener（（android.speech.RecognitionListener）this）处阻塞；然后，它向我显示了这个警告：未找到用于“Android API 29平台”的反编译.class文件、字节码版本52.0（Java 8）源代码。我验证了android SDK列表，并且确实安装了android 9++（Q）。@AndresVasquez MainActivity不是识别侦听器。如果不实现RecognitionListener或扩展某个实现的类，则无法将其强制转换为RecognitionListener。另一方面，如果您实现了该接口，就不需要强制转换。谢谢。我得到了它！