AndroidCamera不会打开

Question

我跟着this guide得到我的基地Cameraapplication，我已经改变了一些代码来得到它的工作，因为教程中有一些缺点和类似的东西，但背面相机预览和一切正在工作，并且我可以拍下保存在SD卡上的照片。

现在我的问题，我想能够切换到frontfacing相机，但我不明白它的工作。我已经在网上搜索了几个小时，但是我无法完成它的工作。我得到这个错误：

java.lang.RuntimeException: Fail to connect to camera service 

这是代码，当我尝试切换到摄像头：

OnClickListener switchCameraListener = new OnClickListener() { 
    @Override 
    public void onClick(View v) { 

     findFrontFacingCamera(); 
     chooseCamera(); 
    } 
}; 

所有其他代码是链接我送的。如果这使得它更容易，我当然可以在这里发布，所以请告诉我是否应该在此处编写任何其他代码。我非常感谢任何帮助。谢谢！ /亚历克斯

编辑：现在发布的代码上我的两个类：

package com.alexborghesi.androidcameraexample; 

import java.io.File; 
import java.io.FileNotFoundException; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.text.SimpleDateFormat; 
import java.util.Date; 

import android.app.Activity; 
import android.content.Context; 
import android.content.pm.PackageManager; 
import android.hardware.Camera; 
import android.hardware.Camera.CameraInfo; 
import android.hardware.Camera.PictureCallback; 
import android.hardware.Sensor; 
import android.hardware.SensorEvent; 
import android.hardware.SensorEventListener; 
import android.hardware.SensorManager; 
import android.os.Bundle; 
import android.util.Log; 
import android.view.SurfaceHolder; 
import android.view.SurfaceView; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.view.WindowManager; 
import android.widget.Button; 
import android.widget.RelativeLayout; 
import android.widget.TextView; 
import android.widget.Toast; 

public class cameraClass extends Activity implements  SensorEventListener { 

Shake shake = new Shake(); 
private Camera mCamera; 
private previewClass mPreview; 
private PictureCallback mPicture; 
private Button capture, switchCamera; 
private Context myContext; 
private RelativeLayout cameraPreview; 
private boolean cameraFront = false; 


Sensor acc; 
SensorManager accManager; 
TextView textView; 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); 
    myContext = this; 

    accManager = (SensorManager) getSystemService(SENSOR_SERVICE); 
    acc = accManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER); 
    accManager.registerListener(this, acc, SensorManager.SENSOR_DELAY_UI); 

    textView = (TextView) findViewById(R.id.textView); 

    initialize(); 
} 

public void initialize() { 
    cameraPreview = (RelativeLayout) findViewById(R.id.camera_preview); 
    mPreview = new previewClass(myContext, mCamera); 
    cameraPreview.addView(mPreview); 

    capture = (Button) findViewById(R.id.button_capture); 
    capture.setOnClickListener(captureListener); 

    switchCamera = (Button) findViewById(R.id.button_ChangeCamera); 
    switchCamera.setOnClickListener(switchCameraListener); 

} 

private int findFrontFacingCamera() { 
    int cameraId = -1; 
    // Search for the front facing camera 
    int numberOfCameras = Camera.getNumberOfCameras(); 
    for (int i = 0; i < numberOfCameras; i++) { 
     CameraInfo info = new CameraInfo(); 
     Camera.getCameraInfo(i, info); 
     if (info.facing == CameraInfo.CAMERA_FACING_FRONT) { 
      cameraId = i; 
      cameraFront = true; 
      break; 
     } 
    } 
    return cameraId; 
} 

private int findBackFacingCamera() { 
    int cameraId = -1; 
    //Search for the back facing camera 
    //get the number of cameras 
    int numberOfCameras = Camera.getNumberOfCameras(); 
    //for every camera check 
    for (int i = 0; i < numberOfCameras; i++) { 
     CameraInfo info = new CameraInfo(); 
     Camera.getCameraInfo(i, info); 
     if (info.facing == CameraInfo.CAMERA_FACING_BACK) { 
      cameraId = i; 
      cameraFront = false; 
      break; 
     } 
    } 
    return cameraId; 
} 

public void onResume() { 

    super.onResume(); 

    if (!hasCamera(myContext)) { 
     Toast toast = Toast.makeText(myContext, "Sorry, your phone does not have a camera!", Toast.LENGTH_LONG); 
     toast.show(); 
     finish(); 
    } 
    if (mCamera == null) { 
     if (findFrontFacingCamera() < 0) { 
      Toast.makeText(this, "No front facing camera found.", Toast.LENGTH_LONG).show(); 
      switchCamera.setVisibility(View.GONE); 
     } 
     mCamera = Camera.open(findBackFacingCamera()); 
     mPicture = getPictureCallback(); 


     mPreview.refreshCamera(mCamera); 
    } 

} 

; 

public void chooseCamera() { 
    //if the camera preview is the front 
    if (cameraFront == false) { 
     int cameraId = findBackFacingCamera(); 
     if (cameraId <= 0) { 
      //open the backFacingCamera 
      //set a picture callback 
      //refresh the preview 

      mCamera = Camera.open(cameraId); 
      mPicture = getPictureCallback(); 
      mPreview.refreshCamera(mCamera); 
     } 
    } else { 
     int cameraId = findFrontFacingCamera(); 
     if (cameraId >= 1) { 
      //open the frontFacingCamera 
      //set a picture callback 
      //refresh the preview 

      mCamera = Camera.open(cameraId); 
      mPicture = getPictureCallback(); 
      mPreview.refreshCamera(mCamera); 
     } 
    } 
} 

@Override 
protected void onPause() { 
    super.onPause(); 
    //mSensorManager.unregisterListener(mSensorListener); 
    //when on Pause, release camera in order to be used from other applications 
    releaseCamera(); 
} 

private boolean hasCamera(Context context) { 
    //check if the device has camera 
    if (context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)) { 
     return true; 
    } else { 
     return false; 
    } 
} 

private PictureCallback getPictureCallback() { 
    PictureCallback picture = new PictureCallback() { 

     @Override 
     public void onPictureTaken(byte[] data, Camera camera) { 
      //make a new picture file 
      File pictureFile = getOutputMediaFile(); 

      if (pictureFile == null) { 
       return; 
      } 
      try { 
       //write the file 
       FileOutputStream fos = new FileOutputStream(pictureFile); 
       fos.write(data); 
       fos.close(); 
       Toast toast = Toast.makeText(myContext, "Picture saved: " + pictureFile.getName(), Toast.LENGTH_LONG); 
       toast.show(); 

      } catch (FileNotFoundException e) { 
      } catch (IOException e) { 
      } 

      //refresh camera to continue preview 
      mPreview.refreshCamera(mCamera); 
     } 
    }; 
    return picture; 
} 




OnClickListener captureListener = new OnClickListener() { 
    @Override 
    public void onClick(View v) { 
     mCamera.takePicture(null, null, mPicture); 
    } 
}; 

OnClickListener switchCameraListener = new OnClickListener() { 
    @Override 
    public void onClick(View v) { 

     findFrontFacingCamera(); 
     chooseCamera(); 
    } 
}; 

//make picture and save to a folder 
private static File getOutputMediaFile() { 
    //make a new file directory inside the "sdcard" folder 
    File mediaStorageDir = new File("/sdcard/", "JCG Camera"); 

    //if this "JCGCamera folder does not exist 
    if (!mediaStorageDir.exists()) { 
     //if you cannot make this folder return 
     if (!mediaStorageDir.mkdirs()) { 
      return null; 
     } 
    } 

    //take the current timeStamp 
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date()); 
    File mediaFile; 
    //and make a media file: 
    mediaFile = new File(mediaStorageDir.getPath() + File.separator + "IMG_" + timeStamp + ".jpg"); 

    return mediaFile; 
} 







private void releaseCamera() { 
    // stop and release camera 
    if (mCamera != null) { 
     mCamera.release(); 
     mCamera = null; 
    } 
} 

@Override 
public void onSensorChanged(SensorEvent event) { 

    if(shake.thresholdSpan(event, -6.0, 6.0)){ 
     textView.setText("I'm Shaking!"); 

    } 
    else{ 
     textView.setText("SKAKA DÅ!!"); 
    } 


} 

@Override 
public void onAccuracyChanged(Sensor sensor, int accuracy) { 

} 
} 

第二类：

package com.alexborghesi.androidcameraexample; 

import java.io.IOException; 

import android.content.Context; 
import android.content.pm.ActivityInfo; 
import android.hardware.Camera; 
import android.util.Log; 
import android.view.Display; 
import android.view.Surface; 
import android.view.SurfaceHolder; 
import android.view.SurfaceView; 
import android.view.WindowManager; 

public class previewClass extends SurfaceView implements SurfaceHolder.Callback { 


private SurfaceHolder mHolder; 
private Camera mCamera; 
private Camera.Parameters mParameters; 

public previewClass(Context context, Camera camera) { 
    super(context); 
    mCamera = camera; 
    mHolder = getHolder(); 
    mHolder.addCallback(this); 
    // deprecated setting, but required on Android versions prior to 3.0 
    mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); 
} 

public void surfaceCreated(SurfaceHolder holder) { 
    try { 
     // create the surface and start camera preview 
     if (mCamera == null) { 

      mCamera.setPreviewDisplay(holder); 

      mCamera.startPreview(); 

     } 
    } catch (IOException e) { 
     Log.d(VIEW_LOG_TAG, "Error setting camera preview: " + e.getMessage()); 
    } 
} 

public void refreshCamera(Camera camera) { 
    if (mHolder.getSurface() == null) { 
     // preview surface does not exist 
     return; 
    } 
    // stop preview before making changes 
    try { 
     mCamera.stopPreview(); 
    } catch (Exception e) { 
     // ignore: tried to stop a non-existent preview 
    } 
    // set preview size and make any resize, rotate or 
    // reformatting changes here 
    // start preview with new settings 

    setCamera(camera); 
    try { 
     mCamera.setPreviewDisplay(mHolder); 

     mCamera.setDisplayOrientation(90); 
     mCamera.startPreview(); 
    } catch (Exception e) { 
     Log.d(VIEW_LOG_TAG, "Error starting camera preview: " + e.getMessage()); 
    } 
} 

public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) { 
    { 

     mCamera.stopPreview(); 
     // If your preview can change or rotate, take care of those events here. 
     // Make sure to stop the preview before resizing or reformatting it. 
     refreshCamera(mCamera); 
    } 
} 

public void setCamera(Camera camera) { 
    //method to set a camera instance 
    mCamera = camera; 
} 


@Override 
public void surfaceDestroyed(SurfaceHolder holder) { 
    // TODO Auto-generated method stub 
    // mCamera.release(); 

} 

}

我的设备运行的是Android 4.2.2。

Answer 1

解决自己的问题，问题是，我还没有公布在镜头前我试图用第二个摄像头。

我只是说这行代码：

releaseCamera(); 

这种方法包含此：

private void releaseCamera() { 
// stop and release camera 
if (mCamera != null) { 
    mCamera.release(); 
    mCamera = null; 
} 
} 

，然后在我的点击收听它看起来像这样：

OnClickListener switchCameraListener = new OnClickListener() { 
    @Override 
    public void onClick(View v) { 
     releaseCamera(); 
     chooseCamera(); 
    } 
}; 

Answer 2

你说Manifest.xml中的摄像头权限？

<manifest 

    <application 

     <Uses-permission android: name = "android.permission.CAMERA" /> 

    </ Application> 

</ Manifest> 

我已经帮助