安卓：无法连接到相机上的服务变化targetSdkVersion

Question

我按照我的相机应用程序的manifest.xml设置：

<uses-sdk 
    android:minSdkVersion="7" 
    android:targetSdkVersion="8" /> 

现在我将它更改为：

<uses-sdk 
    android:minSdkVersion="7" 
    android:targetSdkVersion="13" /> 

问题是：我的应用程序无法再打开相机。此行引发错误：

this.camera = Camera.open(); 

ERRORMESSAGE：

Fail to connect to camera service

奇怪的事情，顺便说一句：首先是新设置的应用程序后，我没有得到运行相机设备了（所有其他照片应用也在启动时崩溃）。我必须重新启动设备才能够再次使用相机。

有人可以帮我吗？

我Preview.java类：

package net.mt.lib.cc; 

import java.io.IOException; 
import java.util.Collections; 
import java.util.Comparator; 
import java.util.Hashtable; 
import java.util.List; 

import net.mt.lib.Tools; 
import org.json.JSONException; 
import org.json.JSONObject; 

import android.app.Activity; 
import android.app.ActivityManager; 
import android.app.ActivityManager.MemoryInfo; 
import android.content.Context; 
import android.hardware.Camera; 
import android.hardware.Camera.ErrorCallback; 
import android.hardware.Camera.Size; 
import android.os.Build; 
import android.os.Debug; 
import android.util.Log; 
import android.view.SurfaceHolder; 
import android.view.SurfaceView; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.Toast; 

import com.crittercism.app.Crittercism; 
import com.flurry.android.FlurryAgent; 

/** 
* 
* openCamera() 
* onSizeChanged() 
* onLayout() 
* onLayout() 
* surfaceCreated() 
* surfaceChanged() 
* onLayout() 
*/ 
class Preview extends ViewGroup implements SurfaceHolder.Callback { // <1> 
    private static final String TAG = "Preview"; 

    SurfaceHolder mHolder; // <2> 
    public Camera camera; // <3> 
    SurfaceView mSurfaceView; 
    BaseCameraActivity cameraActivity; 
    int l2 = 0, t2 = 0, r2 = 0, b2 = 0; 
    int padding = 20; 
    PreviewCallback cb; 
    private double downscalingFactor = 1; 
    // the size of this view. gets set in onMeasure() 
    int fullWidth, fullHeight; 
    Size bestPictureSize = null; 
    Size bestPreviewSize = null; 

    private String allResolutions; 

    private Context context; 

    public Preview(Context context, PreviewCallback callback) { 
     super(context); 
     this.cb = callback; 
     init(context); 
    } 



    private void init(Context context) { 
     setKeepScreenOn(true); 
     cameraActivity = (BaseCameraActivity) context; 
     mSurfaceView = new SurfaceView(context); 
     addView(mSurfaceView); 
     this.context = context; 
     mHolder = mSurfaceView.getHolder(); // <4> 
     mHolder.addCallback(this); // <5> 
     mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); // <6> 
    } 


    public void openCamera() { 
     Log.d(TAG,"openCamera()"); 
     if (this.camera == null) { 
      try{ 
       this.camera = Camera.open(); 
       this.camera.setErrorCallback(new ErrorCallback() { 
        @Override 
        public void onError(int error, Camera camera) { 
         Log.e(TAG, "error! code:"+error); 
         Toast.makeText(cameraActivity, "Camera error occured: "+error, 8000).show(); 
        } 
       }); 
       requestLayout(); // -> onSizeChanged() -> onLayout() 
      }catch (Exception e) { 
       String errorMessage = "Manufacturer: "+Build.MANUFACTURER+"; Model:"+Build.MODEL+"; Camera: "+this.camera+"; Stacktrace:"+Tools.exception2String(e); 
       Log.d(TAG,"error occured: "+errorMessage); 
       FlurryAgent.onError("1", errorMessage, "Preview.openCamera()"); 
       Toast.makeText(cameraActivity, "Uuups, I am sorry! Could not connect to the camera device. Please restart me or your phone.", 8000).show(); 
       Crittercism.logHandledException(e); 
      } 
     } 
    } 



    @Override 
    protected void onSizeChanged(int w, int h, int oldw, int oldh) { 
     Log.d(TAG,"onSizeChanged() "+w+" "+h); 
     fullWidth = w; 
     fullHeight = h; 
     if(fullWidth < fullHeight){ 
      int tmp = fullHeight; 
      fullHeight = fullWidth; 
      fullWidth = tmp; 
      Log.d(TAG,"switched:"+fullWidth+"x"+fullHeight); 
     }else{ 
      Log.d(TAG,"fullSize:"+fullWidth+"x"+fullHeight); 
     } 
     if(this.camera != null){ 
      this.setCameraPreviewSize(); 
      this.setCameraPictureSize(); 
      if (getChildCount() > 0) { 
       final View child = getChildAt(0); 
       Log.d(TAG,"r:"+this.getPreviewRight()+" l:"+this.getPreviewLeft()+" b:"+this.getPreviewBottom()+" t:"+this.getPreviewTop()); 
       child.layout(this.getPreviewLeft(), this.getPreviewTop(), this.getPreviewRight(), this.getPreviewBottom()); 
       cb.previewReady(getPreviewLeft(), getPreviewTop(), getPreviewRight()-getPreviewLeft(), getPreviewBottom() - getPreviewTop(), getBestPictureSize().width, getBestPictureSize().height, (int) downscalingFactor, allResolutions); 
      } 
     } 

     super.onSizeChanged(w, h, oldw, oldh); 
    } 

    private void calcScaledPreviewSize(){  
     int previewWidth = getBestPreviewSize().width; 
     int previewHeight = getBestPreviewSize().height; 
     float scaledWidth; 
     float scaledHeight; 

     Log.d(TAG,"preview width: "+previewWidth+", preview height: "+previewHeight); 
     Log.d(TAG,"display width: "+fullWidth+", display height: "+fullHeight); 
     float previewRatio = (float) previewWidth/(float) previewHeight; 
     float displayRatio = (float) fullWidth/(float) fullHeight; 

     if(displayRatio >= previewRatio){ // the display is wider then the preview image 
      scaledHeight = fullHeight - 2*padding; 
      scaledWidth = scaledHeight * previewRatio; 
      l2 = (int) (fullWidth - scaledWidth)/2; 
      t2 = padding; 
      r2 = (int) (fullWidth + scaledWidth)/2; 
      b2 = (int) scaledHeight + padding; 

     }else{ 
      scaledWidth = fullWidth - 2*padding; 
      scaledHeight = scaledWidth/previewRatio; 
      l2 = padding; 
      t2 = (int) (fullHeight - scaledHeight)/2; 
      r2 = (int) scaledWidth + padding; 
      b2 = (int) (fullHeight + scaledHeight)/2;  
     } 
    } 

    public int getPreviewTop() { 
     if(this.t2 == 0){ 
      this.calcScaledPreviewSize(); 
     } 
     return t2; 
    } 
    public int getPreviewBottom() { 
     if(this.b2 == 0){ 
      this.calcScaledPreviewSize(); 
     } 
     return b2; 
    } 
    public int getPreviewLeft() { 
     if(this.l2 == 0){ 
      this.calcScaledPreviewSize(); 
     } 
     return l2; 
    } 
    public int getPreviewRight() { 
     if(this.r2 == 0){ 
      this.calcScaledPreviewSize(); 
     } 
     return r2; 
    } 
    public int getPreviewWidth() { 
     return this.getPreviewRight()-this.getPreviewLeft(); 
    } 
    public int getPreviewHeight() { 
     return this.getPreviewBottom()-this.getPreviewTop(); 
    } 

    private void setCameraPreviewSize() { 
     Camera.Parameters parameters = camera.getParameters(); 
     if(parameters.getPreviewSize() != this.getBestPreviewSize()){ 
      parameters.setPreviewSize(this.getBestPreviewSize().width, this.getBestPreviewSize().height); 
      this.camera.setParameters(parameters); 
     } 
    } 

    private void setCameraPictureSize() { 
     Camera.Parameters parameters = this.camera.getParameters(); 
     if(parameters.getPictureSize() != this.getBestPictureSize()){ 
      parameters.setPictureSize(getBestPictureSize().width, getBestPictureSize().height); 
      this.camera.setParameters(parameters); 
     } 
    } 

    @Override 
    protected void onLayout(boolean changed, int l, int t, int r, int b) { 
     Log.d(TAG,"onLayout()"); 
     /* 
     if (changed && getChildCount() > 0 && this.camera != null) { 
      final View child = getChildAt(0); 
      Log.d(TAG,"r:"+this.getPreviewRight()+" l:"+this.getPreviewLeft()+" b:"+this.getPreviewBottom()+" t:"+this.getPreviewTop()); 
      child.layout(this.getPreviewLeft(), this.getPreviewTop(), this.getPreviewRight(), this.getPreviewBottom()); 
      cameraActivity.initOverlay(this.getPreviewLeft(),this.getPreviewTop(),this.getPreviewRight(),this.getPreviewBottom()); 
     }*/ 
    } 
    public Size getBestPictureSize() { 
     if(this.bestPictureSize == null){ 
      this.calculateOptimalPictureAndPreviewSizes(); 
     } 
     return bestPictureSize; 
    } 

    public Size getBestPreviewSize() { 
     if(this.bestPreviewSize == null){ 
      this.calculateOptimalPictureAndPreviewSizes(); 
     } 
     return bestPreviewSize; 
    } 



    // Called once the holder is ready 
    public void surfaceCreated(SurfaceHolder holder) { // <7> 
     // The Surface has been created, acquire the camera and tell it where 
     // to draw. 
     Log.d(TAG,"surfaceCreated()"); 
     try { 
      if (this.camera != null) { 
       this.camera.setPreviewDisplay(holder); 
      } 
     } catch (IOException exception) { 
      Log.e(TAG, "IOException caused by setPreviewDisplay()", exception); 

     } 
    } 

    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) { 
     Log.d(TAG,"surfaceChanged()"); 
     if (camera != null) { 

      Camera.Parameters parameters = camera.getParameters(); 
      parameters.setPreviewSize(getBestPreviewSize().width, getBestPreviewSize().height); 
      camera.setParameters(parameters); 
      camera.startPreview(); 
      cb.onPreviewStart(); 
      requestLayout(); 
     } 
    } 

    public void surfaceDestroyed(SurfaceHolder holder) { // <14> 
     Log.d(TAG,"surfaceDestroyed()"); 
     if(this.camera != null){ 
      camera.stopPreview(); 
      camera.lock(); 
      camera.release(); 
      this.camera = null; 
     } 
    } 

    public void releaseCamera(){ 
     Log.d(TAG,"releaseCamera()"); 
     if (camera != null) { 
      camera.stopPreview(); 
      camera.setPreviewCallback(null); 
      camera.release(); 
      camera = null; 
     } 
    } 


} 

预览被初始化这样的（从主要活动）：

@Override 
    protected void onResume() { 
     super.onResume(); 
     Log.d(TAG,"onResume()"); 

     previewLayout.removeAllViews(); 
     preview = new Preview(this, this); 
     previewLayout.addView(preview, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,ViewGroup.LayoutParams.MATCH_PARENT)); 
     preview.openCamera(); 

    } 

和清单：

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
    package="net.mc.ccPro" 
    android:versionCode="35" 
    android:versionName="3.5" > 

    <application 
     android:hardwareAccelerated="true" 
     android:icon="@drawable/icon" 
     android:label="@string/app_name" 
     android:largeHeap="true" > 
     <activity 
      android:name=".ccProActivity" 
      android:configChanges="keyboard|orientation|keyboardHidden" 
      android:label="@string/app_name" 
      android:windowSoftInputMode="adjustPan" > 
      <intent-filter> 
       <action android:name="android.intent.action.MAIN" /> 
       <category android:name="android.intent.category.LAUNCHER" /> 
      </intent-filter> 
      <intent-filter> 
       <action android:name="android.media.action.IMAGE_CAPTURE" /> 
       <category android:name="android.intent.category.DEFAULT" /> 
      </intent-filter> 
     </activity> 
     <activity 
      android:name="net.mc.lib.cc.PreferenceActivity" 
      android:label="@string/set_preferences" > 
     </activity> 

    </application> 

    <supports-screens 
      android:largeScreens="true" 
      android:normalScreens="true" 
      android:smallScreens="true" 
      android:resizeable="true" 
      android:anyDensity="true" /> 


    <uses-sdk 
     android:minSdkVersion="7" 
     android:targetSdkVersion="8" /> 

    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /> 
    <uses-permission android:name="android.permission.CAMERA" /> 
    <uses-permission android:name="android.permission.INTERNET" /> 
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> 
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> 

    <uses-library android:name="net.mc.lib.cc" /> 
    <uses-feature 
     android:name="android.hardware.camera.autofocus" 
     android:required="false" /> 

    <supports-screens 
     android:largeScreens="true" 
     android:normalScreens="true" 
     android:smallScreens="true" 
     android:xlargeScreens="true" /> 

</manifest> 

Answer 1

使用此代码初始化相机：

 Camera camera; 
     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD) { 
      int numberOfCameras = Camera.getNumberOfCameras(); 
      CameraInfo cameraInfo = new CameraInfo(); 
      for (int i = 0; i < numberOfCameras; i++) { 
       Camera.getCameraInfo(i, cameraInfo); 
       if (cameraInfo.facing == CameraInfo.CAMERA_FACING_BACK) 
        camera = Camera.open(i); 
      } 
     } 
     if (camera == null) 
      camera = Camera.open(); 
     ... 

Answer 2

尝试将此行添加到您的AndroidManifest还有：

<uses-feature android:name="android.hardware.camera" />