相关疑难解决方法(0)

我正在尝试在Android上创建一个录像机,并且我已经准备好了应该正常工作的代码 - 但我不断收到错误消息start failed: -19.

这是我的代码:

public boolean startRecording() {
    try {
        camera.unlock();
        mediaRecorder = new MediaRecorder();
        mediaRecorder.setOnErrorListener(new MediaRecorder.OnErrorListener() {

                @Override
                public void onError(MediaRecorder mr, int what, int extra) {
                Log.i(TAG, "Error");
            }
        });

        mediaRecorder.setCamera(camera);
        mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
        mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
        Log.i(TAG, "a");

        mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
        mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT);
        mediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H263);
        Log.i(TAG, "b");

        mediaRecorder.setMaxDuration(maxDurationInMs); // set to 20000

        String uniqueOutFile = OUTPUT_FILE + System.currentTimeMillis() + ".3gp";
        File outFile = new File(uniqueOutFile);
        if (outFile.exists()) {
            outFile.delete();
        }
        mediaRecorder.setOutputFile(uniqueOutFile);
        mediaRecorder.setVideoFrameRate(videoFramesPerSecond); // set to 20
        mediaRecorder.setVideoSize(sView.getWidth(), sView.getHeight());
        Log.i(TAG, "c");

        mediaRecorder.setPreviewDisplay(holder.getSurface()); …

我想制作一个录音机应用程序，但当我单击“开始录音”按钮时它崩溃了。我在 android.media.MediaRecorder.start(Native Method) 处收到一条错误消息 java.lang.IllegalStateException。我还附上了日志。

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 …