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Question

我想创建一个录音机应用程序，但是当我点击＆＃34;开始录制＆＃34;它会崩溃按钮。我在android.media.MediaRecorder.start（Native Method）中收到一条错误说java.lang.IllegalStateException。我也附上了日志。

package com.example.sahil.chuckit;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.app.Activity;
import android.media.MediaPlayer;
import android.media.MediaRecorder;
import android.os.Environment;
import java.io.File;

public class MainActivity extends Activity {

    private static Button submit;
    private static Button submit2;
    private static Button submit3;
    private static Button submit4;
    private MediaPlayer mediaPlayer;
    private MediaRecorder recorder;
    private String output_file;

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

        output_file = Environment.getExternalStorageState() +    "/audiorecorder.3gpp";
        OnClickButtonListener();OnClickButtonListener1();
        OnClickButtonListener3();OnClickButtonListener4();
     }
     public void OnClickButtonListener(){
        submit =(Button)findViewById(R.id.button);
        submit.setOnClickListener(
                new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {

                        beginRecording();

                    }
                    }

        );

    }
    public void OnClickButtonListener1(){
        submit2 =(Button)findViewById(R.id.button2);
        submit2.setOnClickListener(
                new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        stopRecording();
                    }
                }
        );

    }

    public void OnClickButtonListener3(){
        submit3 =(Button)findViewById(R.id.button3);
        submit3.setOnClickListener(
                new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        try {
                            playRecording();
                        } catch (Exception e) {
                            e.printStackTrace();
                        }
                    }
                }
        );

    }
    public void OnClickButtonListener4(){
        submit4 =(Button)findViewById(R.id.button4);
        submit4.setOnClickListener(
                new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                      stopPlayback();
                    }
                }
        );

    }
    private void ditchMediaRecorder() {
        if (recorder != null)
            recorder.release();
    }
    private void beginRecording() {
        ditchMediaRecorder();
        File outFile=new File(output_file);

        if (outFile.exists())
        { outFile.delete();}

        recorder=new MediaRecorder();
        recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
        recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
        recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
        recorder.setOutputFile(output_file);
        recorder.start();
    }
    private void stopRecording() {
        if(recorder!=null)
            recorder.stop();
    }

    private void playRecording() throws Exception {
        ditchMediaPlayer();
        mediaPlayer=new MediaPlayer();
        mediaPlayer.setDataSource(output_file);
        mediaPlayer.prepare();
        mediaPlayer.start();
    }

    private void ditchMediaPlayer() {
        if(mediaPlayer!=null)
        {
            try{
                mediaPlayer.release();
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }

    private void stopPlayback() {
        if (mediaPlayer!=null)
            mediaPlayer.stop();
    }




}

logcat的：

LOG:06-30 05:11:12.603 24621-24621/com.example.sahil.chuckit E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.sahil.chuckit, PID: 24621 java.lang.IllegalStateException
    at android.media.MediaRecorder.start(Native Method)
    at com.example.sahil.chuckit.MainActivity.beginRecording(MainActivity.java:111)
    at com.example.sahil.chuckit.MainActivity.access$000(MainActivity.java:22)
    at com.example.sahil.chuckit.MainActivity$1.onClick(MainActivity.java:46)
    at android.view.View.performClick(View.java:5198)
    at android.view.View$PerformClick.run(View.java:21147)
    at android.os.Handler.handleCallback(Handler.java:739)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:148)
    at android.app.ActivityThread.main(ActivityThread.java:5417)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
06-30 05:11:14.891 24621-24621/com.example.sahil.chuckit I/Process: Sending signal. PID: 24621 SIG: 9

Answer 1

您忘记在recorder.prepare()功能recordeer.start()功能之前致电beginRecording。

准备功能将关注许多事情，例如将模拟数据转换为数字音频以进行压缩以及存储文件的位置等

Answer 2

您必须考虑到，MediaRecorder以及MediaPlayer都有自己的状态机，强制您按特定顺序执行某些操作。

您尝试在准备MediaRecorder时开始录制。致电

recorder.prepare();

在：

recorder.start();

Answer 3

在setOutFormat（）之后但prepare（）之前调用此函数。

这就是我编写此方法名称时我的android studio文档对话框所说的内容。关键是您应该在prepare（）之前调用此方法。
这是一个例子：

private void startRecording() {
    mediaRecorder = new MediaRecorder();
    mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
    mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
    mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
    File outputFolder = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/MediaMaster/Dub/");
    Log.i(TAG, "startRecording: creating output file " + outputFolder.mkdirs());
    File output = new File(outputFolder.getAbsolutePath()+"out" + new Date().getTime() + ".3gpp");
    mediaRecorder.setOutputFile(output.getAbsolutePath());
    mediaRecorder.setMaxDuration(3000);
    try {
        mediaRecorder.prepare();
    } catch (IOException e) {
        Log.e(TAG, "startRecording: ", e);
    }
    mediaRecorder.start();
}

Answer 4

`if (audioRecorder != null) {
            try {
                audioRecorder.stop();
                audioRecorder.reset();
                audioRecorder.release();
                audioRecorder = null;
                
            } catch (IllegalStateException e) {
                e.printStackTrace();
            }
        }`

因为我们不释放记录器，而只是停止记录器重新启动时，我们会到达android.media.MediaRecorder.start（本机方法）花了1个小时才弄清

HappyCoding

Answer 5

由以下原因引起：android.media.MediaRecorder.native_start（本机方法）处的java.lang.IllegalStateException

我遇到了有关媒体记录器的问题。它记录的很完美，但是我尝试再次记录屏幕，然后出现此错误，媒体记录器崩溃了。在尝试了许多东西之后，我尝试了这个 mediarecorder.release（）; 每次停止记录时，使用这种方法都会释放媒体记录器并使我能够再次记录。

android.media.MediaRecorder.start（Native Method）中的java.lang.IllegalStateException

5 个答案:

HappyCoding