更新： 我可以解决旋转问题（我稍后会通过答案编写修改后的代码）。但是在开始活动时我看不到相机的预览。 我在下面看到链接，但没有帮助我。 Can't create Camera preview in onCreate? [surfaceview2中的Android相机预览]
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我有一个Android应用程序，下面有捕获视频代码。除了2件事以外，每件事都能正常工 首先是：在拍摄之前我无法预览相机。我想在启动VideoRecorderActivity1时通过我的相机进行预览。 第二：当我按下ToggleButton的开头时，那么每件东西都会旋转90度，这是非常糟糕的。但输出文件具有正确的显示度。您可以使用下面的代码并查看结果。 请帮助解决我的应用问题。谢谢。 这是我的Classess。
import java.io.File;
import java.io.IOException;
import android.hardware.Camera.Parameters;
import android.app.Activity;
import android.hardware.Camera;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.KeyEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Toast;
import android.widget.ToggleButton;
public class VideoRecorderActivity1 extends Activity
implements SurfaceHolder.Callback
{
private SurfaceHolder surfaceHolder;
private SurfaceView surfaceView;
public MediaRecorder mrec= new MediaRecorder();
private Camera mCamera;
private ToggleButton mToggleButton=null;
private String Videname="";
private String Videopath="";
private VideoRecorder myVideo=null;
private static Boolean isRecording=false;
String filePath= Environment.getExternalStorageDirectory().getAbsolutePath()+File.separator
+"My Audios"+File.separator+"video2camera5.3gpp";
private Boolean ExistVideo(String path1)
{
File file = new File(SDcard.Dir_recordedVideos );
File list[] = file.listFiles();
for( int i=0; i< list.length; i++)
{
if(list[i].getPath().equals(path1))
return true;
}
return false;
}
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.recorder_video);
InitializeUI();
mToggleButton.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v)
{
if (((ToggleButton) v).isChecked())
try
{ myVideo=new VideoRecorder();
do{
myVideo.setName();
Videname=myVideo.getName();
myVideo.setPath();
Videopath=myVideo.getPath();
}while(ExistVideo(Videopath));
startRecording();
}
catch (Exception e)
{
String message = e.getMessage();
Log.i(null, "Problem Start"+message);
if(mrec!= null)
mrec.release();
}
else
stopRecording();
}
});
}
protected void startRecording() throws IOException
{
String state = android.os.Environment.getExternalStorageState();
if (!state.equals(android.os.Environment.MEDIA_MOUNTED))
{
throw new IOException("SD Card is not mounted. It is " + state + ".");
}
// make sure the directory we plan to store the recording in exists
File directory = new File(this.Videopath).getParentFile();
if (!directory.exists() && !directory.mkdirs())
{
throw new IOException("Path to file could not be created.");
}
mrec = new MediaRecorder(); // Works well
mCamera.unlock();
mrec.setCamera(mCamera);
mrec.setPreviewDisplay(surfaceHolder.getSurface());
mrec.setAudioSource(MediaRecorder.AudioSource.MIC);
mrec.setVideoSource(MediaRecorder.VideoSource.CAMERA);
mrec.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
mrec.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
mrec.setVideoEncoder(MediaRecorder.VideoEncoder.MPEG_4_SP);
mrec.setOutputFile(Videopath);
mrec.prepare();
isRecording=true;
mrec.start();
}
protected void stopRecording()
{
if(mrec !=null)
mrec.stop();
releaseMediaRecorder();
isRecording=false;
}
private void releaseMediaRecorder()
{
if (mrec != null)
{
mrec.reset(); // clear recorder configuration
mrec.release(); // release the recorder object
mrec = null;
mCamera.lock(); // lock camera for later use
}
}
private void releaseCamera()
{
if (mCamera != null)
{
mCamera.release(); // release the camera for other applications
mCamera = null;
}
}
//------------------------------------------------------------
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height)
{
// TODO Auto-generated method stub
}
//------------------------------------------------------------
@Override
public void surfaceCreated(SurfaceHolder holder)
{
if (mCamera != null)
{
Parameters params = mCamera.getParameters();
mCamera.setParameters(params);
}
else
{
Toast.makeText(getApplicationContext(), "Camera not available!", Toast.LENGTH_LONG).show();
VideoRecorderActivity1.this.finish();
}
}
//------------------------------------------------------------
@Override
public void surfaceDestroyed(SurfaceHolder holder)
{
}
//------------------------------------------------------------
public boolean onKeyDown(int keyCode, KeyEvent event)
{
if (keyCode == KeyEvent.KEYCODE_BACK )
{
if(isRecording)
mCamera.stopPreview();
mCamera.release();
VideoRecorderActivity1.this.finish();
}
return super.onKeyDown(keyCode, event);
}
//------------------------------------------------------------
private void InitializeUI()
{
mCamera = Camera.open();
surfaceView = (SurfaceView) findViewById(R.id.surface_camera);
surfaceHolder = surfaceView.getHolder();
surfaceHolder.addCallback(this);
surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
mrec.setPreviewDisplay(surfaceHolder.getSurface());
mToggleButton = (ToggleButton) findViewById(R.id.toggleRecordingButton);
}
}
导入此类：
public class VideoRecorder
{
private String name="";
private static int id=0;
private String path=null;
public VideoRecorder()
{
}
public String getName()
{
return(this.name);
}
public void setName()
{
id++;
this.name="video "+id;
}
public String getPath()
{
return this.path;
}
public void setPath()
{
if (!this.name.contains("."))
{
this.name += ".3gpp";
}
this.path=SDcard.Dir_recordedVideos + this.name;
}
}
答案 0 :(得分：1)
你不是在创建预览我认为，在你的表面创建代码中放了这个：
public void surfaceCreated(SurfaceHolder holder) {
Log.v(TAG,"in surfaceCreated"); //Surface created for video preview and playback
try{
mCamera .setPreviewDisplay(holder);
mCamera .startPreview();
}catch(IOException e)
{
Log.v(TAG,"could not start the preview ");
e.printStackTrace();
}
}
在您的开始记录功能中，请执行以下操作：
protected void startRecording() throws IOException
{
String state = android.os.Environment.getExternalStorageState();
if (!state.equals(android.os.Environment.MEDIA_MOUNTED))
{
throw new IOException("SD Card is not mounted. It is " + state + ".");
}
// make sure the directory we plan to store the recording in exists
File directory = new File(this.Videopath).getParentFile();
if (!directory.exists() && !directory.mkdirs())
{
throw new IOException("Path to file could not be created.");
}
mcamera.stopPreview();
mcamera.unlock();
mrec = new MediaRecorder(); // Works well
mrec.setCamera(mCamera);
mrec.setAudioSource(MediaRecorder.AudioSource.MIC);
mrec.setVideoSource(MediaRecorder.VideoSource.CAMERA);
mrec.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
mrec.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
mrec.setVideoEncoder(MediaRecorder.VideoEncoder.MPEG_4_SP);
mrec.setOutputFile(Videopath);
mrec.setPreviewDisplay(surfaceHolder.getSurface());
mrec.prepare();
isRecording=true;
mrec.start();
}