谁能指出我正在做的错误？我正在尝试录制一个短视频，但不知何故它找到了崩溃的方法。
源代码：
public class Start_recording extends Activity implements SurfaceHolder.Callback
{
MediaRecorder recorder;
SurfaceHolder surfaceHolder;
SurfaceView myVideoView;
Camera camera;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
Intent intent = getIntent();
String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
camera = Camera.open();
camera.unlock();
recorder = new MediaRecorder();
setContentView(R.layout.activity_main_rst);
myVideoView = (SurfaceView)findViewById(R.id.surface_camera);
surfaceHolder = myVideoView.getHolder();
surfaceHolder.addCallback(this);
initMediaRecorder();
boolean exists = (new File(android.os.Environment.getExternalStorageDirectory() + "/Record/")).exists();
if (!exists)
{
new File(android.os.Environment.getExternalStorageDirectory() + "/Record/").mkdirs();
}
try
{
recorder.prepare(); // This is the line of error.
recorder.start();
Thread.sleep(36000);
recorder.stop();
setupActionBar();
}
catch(Exception e)
{
Log.v("Error is there : ",e.toString());
e.printStackTrace();
}
}
public void initMediaRecorder()
{
try
{
recorder.setPreviewDisplay(surfaceHolder.getSurface());
recorder.setCamera(camera);
recorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
recorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
recorder.setVideoEncoder(MediaRecorder.VideoEncoder.MPEG_4_SP);
recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
recorder.setOutputFile(android.os.Environment.getExternalStorageDirectory()+"/Record/test.3gp");
recorder.setMaxDuration(300000);
}
catch(Exception f)
{
Log.v("Exception here : ",f.toString());
f.printStackTrace();
}
}
}
错误 ：
E/MediaRecorderJNI(1575): Application lost the surface
V/Error is there :(1575): java.io.IOException: invalid preview surface
W/System.err(1575): java.io.IOException: invalid preview surface
W/System.err(1575): at android.media.MediaRecorder._prepare(Native Method)
W/System.err(1575): at android.media.MediaRecorder.prepare(MediaRecorder.java:666)
W/System.err(1575): at com.example.project.Start_recording.onCreate(Start_recording.java:51)
我已经在 Manifest 文件中正确添加了权限，并且还设置了 setPreviewDisplay()。但我得到了无效的预览表面。请纠正我。