Androidカメラ+ジャイロスコープ/加速度計アプリが写真を撮るときにクラッシュする

Question

解決策を探しているリンクが多数ありますが、これはAndroidで初めての公式アプリです。私は電卓のような他の小さなものを作っていますが、このようなものはありませんので、私がそれらを読んでもアドバイスと解決策を理解することはできません。

アプリは、基本的に次のない： - ジャイロスコープと加速度計で

1. テイクは円形でユーザが移動として運動の
2. 計算角度を読み。
3. 10度ごとに画像を撮影します。

第1クラスはサーフェイスビューで機能します。 2番目は写真を撮り、センサの読みを計算することです。

私は最初の2つの部分を取り上げました。第三の部分が問題です。 イメージを撮るたびに、アプリケーションがハングアップし、サーフェスビューが機能しなくなります。そして何も起こらない。別の10度回転すると、アプリケーションがクラッシュします。

私が間違っていることを教えてもらえますか？前もって感謝します。

package com.example.mehta.accelerometerin; 

import android.app.Activity; 
import android.content.Context; 
import android.content.pm.PackageManager; 
import android.graphics.Bitmap; 
import android.hardware.Camera; 
import android.hardware.Sensor; 
import android.hardware.SensorEvent; 
import android.hardware.SensorManager; 
import android.net.Uri; 
import android.os.Environment; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.hardware.SensorEventListener; 
import android.hardware.Sensor; 
import android.hardware.SensorEvent; 
import android.util.Log; 
import android.view.SurfaceHolder; 
import android.view.SurfaceView; 
import android.view.View; 
import android.widget.FrameLayout; 
import android.widget.TextView; 
import android.widget.Toast; 

import java.io.ByteArrayOutputStream; 
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 static android.content.ContentValues.TAG; 
import static android.provider.MediaStore.Files.FileColumns.MEDIA_TYPE_IMAGE; 
import static java.lang.Math.sqrt; 







class CameraPreview extends SurfaceView implements SurfaceHolder.Callback { 
    private SurfaceHolder mHolder; 
    private Camera mCamera; 




    private boolean checkCameraHardware(Context context) { 
     if (context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)) { 
      // this device has a camera 
      return true; 
     } else { 
      // no camera on this device 
      return false; 
     } 
    } 




    public CameraPreview(Context context, Camera camera) { 
     super(context); 
     mCamera = camera; 


     // Install a SurfaceHolder.Callback so we get notified when the 
     // underlying surface is created and destroyed. 
     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) { 
     // The Surface has been created, now tell the camera where to draw the preview. 
     try { 
      mCamera.setPreviewDisplay(holder); 
      mCamera.startPreview(); 
     } catch (IOException e) { 
      Log.d(TAG, "Error setting camera preview: " + e.getMessage()); 
     } 
    } 

    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) { 
     // If your preview can change or rotate, take care of those events here. 
     // Make sure to stop the preview before resizing or reformatting it. 


     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 
     try { 
      mCamera.setPreviewDisplay(mHolder); 
      mCamera.setDisplayOrientation(90); 
      mCamera.startPreview(); 

     } catch (Exception e) { 
      Log.d(TAG, "Error starting camera preview: " + e.getMessage()); 
     } 

    } 


    @Override 
    public void surfaceDestroyed(SurfaceHolder holder) { 

    } 


} 


class MainActivity extends AppCompatActivity implements SensorEventListener { 
    private Camera mCamera; 
    private CameraPreview mPreview; 

    private SensorManager senSensorManager; 
    private Sensor senAccelerometer; 
    private Sensor senGyroscope; 
    private long lastUpdate = 0; 
    private float last_x, last_y, last_z; 
    private static final int SHAKE_THRESHOLD = 600; 
    TextView tv1, tv2, tv3, tv4, tv5; 
    int j = 0; 
    int i = 1; 
    int l = 10; 
    int m = 0; 
    private float xg, yg, zg, xa, ya, za; 
    private float x1, y1; 
    float x2, y2; 
    private float xang, yang, zang; 
    private float zacc; 
    private float xacc; 
    private float yacc; 
    private int greset; 
    public static Camera getCameraInstance() { 
     Camera c = null; 
     try { 
      c = Camera.open(); // attempt to get a Camera instance 
     } catch (Exception e) { 
      // Camera is not available (in use or does not exist) 
     } 
     return c; // returns null if camera is unavailable 
    } 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     // Create an instance of Camera 
     mCamera = getCameraInstance(); 

     // Create our Preview view and set it as the content of our activity. 
     mPreview = new CameraPreview(this, mCamera); 
     FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview); 
     preview.addView(mPreview); 
     greset = 0; 
     senSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE); 
     senAccelerometer = senSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER); 
     senGyroscope = senSensorManager.getDefaultSensor(Sensor.TYPE_GYROSCOPE); 

     senSensorManager.registerListener(this,senAccelerometer,SensorManager.SENSOR_DELAY_NORMAL); 
     senSensorManager.registerListener(this,senGyroscope,SensorManager.SENSOR_DELAY_NORMAL); 


    } 



    public static final int MEDIA_TYPE_IMAGE = 1; 
    public static final int MEDIA_TYPE_VIDEO = 2; 

    /** Create a file Uri for saving an image or video */ 
    private static Uri getOutputMediaFileUri(int type){ 
     return Uri.fromFile(getOutputMediaFile(type)); 
    } 

    /** Create a File for saving an image or video */ 
    private static File getOutputMediaFile(int type){ 

     // To be safe, you should check that the SDCard is mounted 
     // using Environment.getExternalStorageState() before doing this. 

     File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
       Environment.DIRECTORY_PICTURES), "MyCameraApp"); 
     // This location works best if you want the created images to be shared 
     // between applications and persist after your app has been uninstalled. 

     // Create the storage directory if it does not exist 
     if (! mediaStorageDir.exists()){ 
      if (! mediaStorageDir.mkdirs()){ 
       Log.d("MyCameraApp", "failed to create directory"); 
       return null; 
      } 
     } 

     // Create a media file name 
     String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date()); 
     File mediaFile; 
     if (type == MEDIA_TYPE_IMAGE){ 
      mediaFile = new File(mediaStorageDir.getPath() + File.separator + 
        "IMG_"+ timeStamp + ".jpg"); 
     } else if(type == MEDIA_TYPE_VIDEO) { 
      mediaFile = new File(mediaStorageDir.getPath() + File.separator + 
        "VID_"+ timeStamp + ".mp4"); 
     } else { 
      return null; 
     } 

     return mediaFile; 
    } 

    private Camera.PictureCallback mPicture = new Camera.PictureCallback() { 

     @Override 
     public void onPictureTaken(byte[] data, Camera camera) { 
      Toast.makeText(getApplicationContext(), "on Picture Taken", Toast.LENGTH_SHORT).show(); 

      File pictureFile = getOutputMediaFile(MEDIA_TYPE_IMAGE); 
      if (pictureFile == null){ 
       Log.d(TAG, "Error creating media file, check storage permissions: "); 
       return; 
      } 

      try { 
       FileOutputStream fos = new FileOutputStream(pictureFile); 
       fos.write(data); 
       fos.close(); 
      } catch (FileNotFoundException e) { 
       Log.d(TAG, "File not found: " + e.getMessage()); 
      } catch (IOException e) { 
       Log.d(TAG, "Error accessing file: " + e.getMessage()); 
      } 
     } 
    }; 



    protected void onPause() { 
     super.onPause(); 
     senSensorManager.unregisterListener(this); 

    } 

    protected void onResume() { 
     super.onResume(); 
     senSensorManager.registerListener(this,senAccelerometer, SensorManager.SENSOR_DELAY_NORMAL); 
     senSensorManager.registerListener(this,senGyroscope,SensorManager.SENSOR_DELAY_NORMAL); 
    } 


    public void onSensorChanged(SensorEvent sensorEvent) { 
     Sensor mySensor = sensorEvent.sensor; 


     if (mySensor.getType() == Sensor.TYPE_GYROSCOPE) { 
      greset ++; 
      zg += sensorEvent.values[1]; 
      xg +=sensorEvent.values[0]; 
      yg +=sensorEvent.values[2]; 
      if(zg>30) 
      { 
       zg=0; 
      } 
      if(xg>30) 
      { 
       xg=0; 
      } 
      if(yg>30) 
      { 
       yg=0; 
      } 
      xang = xg*12; 
      yang = yg*12; 
      zang = zg*12; 
      if(zang>=l) { 
       Toast.makeText(getApplicationContext(), "click="+i, Toast.LENGTH_SHORT).show(); 
       mCamera.stopPreview(); 
       mCamera.takePicture(null,null,mPicture); 
       mCamera.startPreview(); 
       l += 10; 
       i++;} 




      if (greset >10) 
      { 
       xg +=0.1; 

       greset = 0; 
      } 

     } 

     if(mySensor.getType()==Sensor.TYPE_ACCELEROMETER) 
     { 
      xa = sensorEvent.values[0]; 
      za = sensorEvent.values[1]; 
      ya = sensorEvent.values[2]; 



      zacc = (float)(za - (((90 - xang)/ 90) * 9.8)); 


     } 



     if (l > 360) { 
      l = 10; 
     } 
    } 

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

    } 

    public int returnvalue(){ 
     return(i); 
    } 

} 

Answer 1

1. takePicture()呼び出す直前stopPreview()を呼び出さないでください：This method is only valid when preview is active (after startPreview()). Preview will be stopped after the image is takenを。

2. takePicture()を呼び出した直後ではなく、onPictureTaken()からstartPreview()に電話する必要があります。

3. メイン（UI）スレッドではなく、別のハンドラスレッドでカメラを開きます。

あなたのコードには他の問題があるかもしれませんが、これら3つの直ちの問題を修正することから始めましょう。