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我正在开发一个相机应用程序，其中需要在相机视图前放置图像。所以基本上需要在表面视图之上有一个表面视图。

当我尝试运行该应用程序时，我收到以下错误：java.lang.RuntimeException：无法连接到相机服务

图片演示.java

package com.commonsware.android.picture;

import java.io.File;
import java.io.FileOutputStream;

import com.commonsware.android.picture.R;
import android.app.Activity;
import android.graphics.ImageFormat;
import android.hardware.Camera;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.widget.Toast;

public class PictureDemo extends Activity {
  private SurfaceView preview=null;
  private SurfaceHolder previewHolder=null;
  private Camera camera=null;
  private boolean inPreview=false;
  private boolean cameraConfigured=false;

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    preview=(SurfaceView)findViewById(R.id.preview);
    previewHolder=preview.getHolder();
    previewHolder.addCallback(surfaceCallback);
    previewHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
  }

  @Override
  public void onResume() {
    super.onResume();

  //  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD) {
  //   Camera.CameraInfo info=new Camera.CameraInfo();
  //    for (int i=0; i < Camera.getNumberOfCameras(); i++) {
  //      Camera.getCameraInfo(i, info);

  //      if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
  //        camera=Camera.open(i);
  //      }
  //   }
  //  }

    if (camera == null) {
      camera=Camera.open();
    }

    startPreview();
  }

  @Override
  public void onPause() {
    if (inPreview) {
      camera.stopPreview();
    }

    camera.release();
    camera=null;
    inPreview=false;

    super.onPause();
  }

  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    new MenuInflater(this).inflate(R.menu.options, menu);

    return(super.onCreateOptionsMenu(menu));
  }

  @Override
  public boolean onOptionsItemSelected(MenuItem item) {
    if (item.getItemId() == R.id.camera) {
      if (inPreview) {
        camera.takePicture(null, null, photoCallback);
        inPreview=false;
      }
    }

    return(super.onOptionsItemSelected(item));
  }

  private Camera.Size getBestPreviewSize(int width, int height,
                                         Camera.Parameters parameters) {
    Camera.Size result=null;

    for (Camera.Size size : parameters.getSupportedPreviewSizes()) {
      if (size.width <= width && size.height <= height) {
        if (result == null) {
          result=size;
        }
        else {
          int resultArea=result.width * result.height;
          int newArea=size.width * size.height;

          if (newArea > resultArea) {
            result=size;
          }
        }
      }
    }

    return(result);
  }

  private Camera.Size getSmallestPictureSize(Camera.Parameters parameters) {
    Camera.Size result=null;

    for (Camera.Size size : parameters.getSupportedPictureSizes()) {
      if (result == null) {
        result=size;
      }
      else {
        int resultArea=result.width * result.height;
        int newArea=size.width * size.height;

        if (newArea < resultArea) {
          result=size;
        }
      }
    }

    return(result);
  }

  private void initPreview(int width, int height) {
    if (camera != null && previewHolder.getSurface() != null) {
      try {
        camera.setPreviewDisplay(previewHolder);
      }
      catch (Throwable t) {
        Log.e("PreviewDemo-surfaceCallback",
              "Exception in setPreviewDisplay()", t);
        Toast.makeText(PictureDemo.this, t.getMessage(),
                       Toast.LENGTH_LONG).show();
      }

      if (!cameraConfigured) {
        Camera.Parameters parameters=camera.getParameters();
        Camera.Size size=getBestPreviewSize(width, height, parameters);
        Camera.Size pictureSize=getSmallestPictureSize(parameters);

        if (size != null && pictureSize != null) {
          parameters.setPreviewSize(size.width, size.height);
          parameters.setPictureSize(pictureSize.width,
                                    pictureSize.height);
          parameters.setPictureFormat(ImageFormat.JPEG);
          camera.setParameters(parameters);
          cameraConfigured=true;
        }
      }
    }
  }

  private void startPreview() {
    if (cameraConfigured && camera != null) {
      camera.startPreview();
      inPreview=true;
    }
  }

  SurfaceHolder.Callback surfaceCallback=new SurfaceHolder.Callback() {
    public void surfaceCreated(SurfaceHolder holder) {
      // no-op -- wait until surfaceChanged()
    }

    public void surfaceChanged(SurfaceHolder holder, int format,
                               int width, int height) {
      initPreview(width, height);
      startPreview();
    }

    public void surfaceDestroyed(SurfaceHolder holder) {
      // no-op
    }
  };

  Camera.PictureCallback photoCallback=new Camera.PictureCallback() {
    public void onPictureTaken(byte[] data, Camera camera) {
      new SavePhotoTask().execute(data);
      camera.startPreview();
      inPreview=true;
    }
  };

  class SavePhotoTask extends AsyncTask<byte[], String, String> {
    @Override
    protected String doInBackground(byte[]... jpeg) {
      File photo=
          new File(Environment.getExternalStorageDirectory(),
                   "/photo.jpg");

      if (photo.exists()) {
        photo.delete();
      }

      try {
        FileOutputStream fos=new FileOutputStream(photo.getPath());

        fos.write(jpeg[0]);
        fos.close();
      }
      catch (java.io.IOException e) {
        Log.e("PictureDemo", "Exception in photoCallback", e);
      }

      return(null);
    }
  }
}

MySurfaceView.java

package com.commonsware.android.picture;

import java.io.IOException;
import java.nio.Buffer;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.hardware.Camera;
import android.util.AttributeSet;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceHolder.Callback;
import android.view.SurfaceView;

public class MySurfaceView extends SurfaceView implements Callback,
    Camera.PreviewCallback {

    private SurfaceHolder mHolder;

    private Camera mCamera;
    private boolean isPreviewRunning = false;
    private byte [] rgbbuffer = new byte[256 * 256];
    private int [] rgbints = new int[256 * 256];

    protected final Paint rectanglePaint = new Paint();

    public MySurfaceView(Context context, AttributeSet attrs) {
    super(context, attrs);
        rectanglePaint.setARGB(100, 200, 0, 0);
        rectanglePaint.setStyle(Paint.Style.FILL);
        rectanglePaint.setStrokeWidth(2);

        mHolder = getHolder();
        mHolder.addCallback(this);
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_NORMAL);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        canvas.drawRect(new Rect((int) Math.random() * 100,
            (int) Math.random() * 100, 200, 200), rectanglePaint);
        Log.w(this.getClass().getName(), "On Draw Called");
    }

    public void surfaceChanged(SurfaceHolder holder, int format, int width,
            int height) {
    }

    public void surfaceCreated(SurfaceHolder holder) {
        synchronized (this) {
            this.setWillNotDraw(false); // This allows us to make our own draw
                                    // calls to this canvas

            mCamera = Camera.open();

            Camera.Parameters p = mCamera.getParameters();
            p.setPreviewSize(240, 160);
            mCamera.setParameters(p);


            //try { mCamera.setPreviewDisplay(holder); } catch (IOException e)
            //  { Log.e("Camera", "mCamera.setPreviewDisplay(holder);"); }

            mCamera.startPreview();
            mCamera.setPreviewCallback(this);

        }
    }

    public void surfaceDestroyed(SurfaceHolder holder) {
        synchronized (this) {
            try {
                if (mCamera != null) {
                    mCamera.stopPreview();
                    isPreviewRunning = false;
                    mCamera.release();
                }
            } catch (Exception e) {
                Log.e("Camera", e.getMessage());
            }
        }
    }

    public void onPreviewFrame(byte[] data, Camera camera) {
        Log.d("Camera", "Got a camera frame");

        Canvas c = null;

        if(mHolder == null){
            return;
        }

        try {
            synchronized (mHolder) {
                c = mHolder.lockCanvas(null);

                // Do your drawing here
                // So this data value you're getting back is formatted in YUV format and you can't do much
                // with it until you convert it to rgb
                int bwCounter=0;
                int yuvsCounter=0;
                for (int y=0;y<160;y++) {
                    System.arraycopy(data, yuvsCounter, rgbbuffer, bwCounter, 240);
                    yuvsCounter=yuvsCounter+240;
                    bwCounter=bwCounter+256;
                }

                for(int i = 0; i < rgbints.length; i++){
                    rgbints[i] = (int)rgbbuffer[i];
                }

                //decodeYUV(rgbbuffer, data, 100, 100);
                c.drawBitmap(rgbints, 0, 256, 0, 0, 256, 256, false, new Paint());

                Log.d("SOMETHING", "Got Bitmap");

            }
        } finally {
            // do this in a finally so that if an exception is thrown
            // during the above, we don't leave the Surface in an
            // inconsistent state
            if (c != null) {
                mHolder.unlockCanvasAndPost(c);
            }
        }
    }
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest android:versionCode="1"
          android:versionName="1.0"
          package="com.commonsware.android.picture"
          xmlns:android="http://schemas.android.com/apk/res/android">

  <uses-sdk android:minSdkVersion="7" android:targetSdkVersion="11"/>
  <supports-screens android:largeScreens="false"
                    android:normalScreens="true"
                    android:smallScreens="false" android:xlargeScreens="true"/>
  <uses-feature android:name="android.hardware.camera" />
  <uses-feature android:name="android.hardware.camera.front"
                android:required="false" />
  <uses-permission android:name="android.permission.CAMERA" />
  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

  <application android:icon="@drawable/cw"
               android:label="@string/app_name">
    <activity android:configChanges="keyboardHidden|orientation"
              android:label="@string/app_name"
              android:name=".PictureDemo"
              android:screenOrientation="landscape">

      <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
      </intent-filter>    
    </activity>


  </application>
</manifest>

主要的.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_height="match_parent" 
        android:layout_width="match_parent"> 
    <android.view.SurfaceView 
            android:id="@+id/preview"
            android:layout_width="match_parent"
            android:layout_height="match_parent">   
        </android.view.SurfaceView>
    <com.commonsware.android.picture.MySurfaceView 
            android:id="@+id/surface_camera"
            android:layout_width="fill_parent" android:layout_height="10dip"
            android:layout_weight="1">
        </com.commonsware.android.picture.MySurfaceView>
</RelativeLayout>

有人有解决方案吗？

4

1 回答 1

1

问题是我认为相机是一个共享的全局资源，在任何给定时间只能连接一次。具体来说，来自 Camera.open 调用的文档：

对于特定的硬件摄像头，您的应用程序一次应该只有一个处于活动状态的摄像头对象。

于 2012-06-06T20:05:45.253 回答