如何修复“无法连接到相机服务"Android模拟器中的异常 [英] How to fix "Fail to connect to camera service" exception in Android emulator

问题描述

当我在模拟器中运行我的 Android 应用程序时，我遇到了无法连接到相机服务的异常.我已经阅读了各种现有的帖子，但都没有解决这个问题.显然是 Camera.open() 调用失败了.正如许多 SO 帖子所讨论的那样，我最终希望让网络摄像头进入模拟器，但现在只想让应用程序在不被轰炸的情况下运行.我不在乎是否显示任何摄像头视频，因为除了摄像头之外，我还需要测试其他功能，并且无论如何我都会主要在我的设备上测试摄像头.

I'm getting a Fail to connect to camera service exception when I run my Android app in the emulator. I've read the various existing posts but none have fixed this. It is clearly the Camera.open() call which is failing. I would eventually like to get the webcam going in the emulator, as many SO posts discuss, but right now just want the app to run without bombing. I do not care whether any camera video gets shown or not, since there are other features besides the camera that I need to test, and will primarily test the camera on my device anyway.

我的清单似乎没问题.里面有以下几行:

My manifest seems to be ok. The following lines are in it:

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

在我的 AVD 管理器中，我将前后摄像头都设置为仿真"，并将 SD 卡值设置为 64.这些似乎是推荐值.完整的堆栈跟踪现在在下面.解决方案必须简单明了，但是什么?

In my AVD manager I have set both the front and back camera to be "Emulated" and the SD Card value to 64. These seem to be the recommended values. The full stack trace is now below. Solution has to be something straightforward, but what?

10-09 08:14:32.375    2628-2628/com.allinlearning.AILAndroidScanner E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.allinlearning.AILAndroidScanner, PID: 2628
java.lang.RuntimeException: Fail to connect to camera service
        at android.hardware.Camera.native_setup(Native Method)
        at android.hardware.Camera.<init>(Camera.java:350)
        at android.hardware.Camera.open(Camera.java:309)
        at com.allinlearning.AILAndroidScanner.AsynCamPreview.surfaceCreated(AsynCamPreview.java:104)
        at android.view.SurfaceView.updateWindow(SurfaceView.java:572)
        at android.view.SurfaceView.access$000(SurfaceView.java:86)
        at android.view.SurfaceView$3.onPreDraw(SurfaceView.java:175)
        at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:847)
        at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1871)
        at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1000)
        at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5670)
        at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
        at android.view.Choreographer.doCallbacks(Choreographer.java:574)
        at android.view.Choreographer.doFrame(Choreographer.java:544)
        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
        at android.os.Handler.handleCallback(Handler.java:733)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:136)
        at android.app.ActivityThread.main(ActivityThread.java:5017)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:515)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
        at dalvik.system.NativeStart.main(Native Method)

整个类的代码如下.同样，引发异常的是 Camera.open() 调用:

The code for the entire class is below. Again, it's the Camera.open() call that throws the exception:

import java.io.IOException;
import java.util.List;

import android.graphics.Bitmap;
import android.graphics.ImageFormat;
import android.hardware.Camera;
import android.os.AsyncTask;
import android.os.Handler;
import android.os.Looper;
import android.util.Log;
import android.view.SurfaceHolder;
import android.webkit.MimeTypeMap;
import android.widget.ImageView;

public class AsynCamPreview extends MainActivity
        implements SurfaceHolder.Callback,  Camera.PreviewCallback
{

    private Camera mCamera;
    public Camera.Parameters params;
    private SurfaceHolder sHolder;
    private ImageView myCameraPreview = null;
    private Bitmap mBitmap = null;

    // data arrays
    private int[] pixels = null;
    private float[] floatpixels = null;
    private byte[] FrameData = null;

    // Camera params
    public float maxZoom;
    private int imageFormat;
    private int previewSizeWidth;
    private int previewSizeHeight;
    private int camId = 1;

    // flags and counts
    private boolean bProcessing = false;
    private int frameCount = 0;
    private boolean doProcessing = false;
    public boolean mProcessInProgress = false;

    public static final String TAG = "AsynCamPreview";

    private long mTiming[] = new long[50];
    private int mTimingSlot = 0;

    Handler mHandler = new Handler(Looper.getMainLooper());

    static {
//      System.loadLibrary("ImageProcessing");
        Log.i(TAG, "Native library loaded");
    }

    public AsynCamPreview(int previewLayoutWidth, int previewLayoutHeight, ImageView cameraPreview)
    {
        previewSizeWidth = previewLayoutWidth;
        previewSizeHeight = previewLayoutHeight;
        myCameraPreview =cameraPreview;
    }


    @Override
    public void onPreviewFrame(byte[] data, Camera camera)
    {
        // Do nothing for now
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        // TODO Auto-generated method stub
        sHolder = holder;
        if (camId == 0) {
            mCamera = Camera.open(Camera.CameraInfo.CAMERA_FACING_FRONT);
        }
        else {
            mCamera = Camera.open(Camera.CameraInfo.CAMERA_FACING_BACK);
        }

        try {
            mCamera.setPreviewDisplay(holder);
            mCamera.setPreviewCallback(this);
        } catch (IOException e) {
            mCamera.release();
            mCamera= null;
        }

        params = mCamera.getParameters();
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width,
                               int height) {
        // TODO Auto-generated method stub
        params = mCamera.getParameters();
        List<Camera.Size> sizes = params.getSupportedPictureSizes();
        this.params.setPreviewSize(previewSizeWidth, previewSizeHeight);

        mBitmap = Bitmap.createBitmap(previewSizeWidth, previewSizeHeight,
                Bitmap.Config.ARGB_8888);
        myCameraPreview.setImageBitmap(mBitmap);

        pixels = new int[previewSizeWidth * previewSizeHeight];
        //floatpixels = new float[previewSizeWidth * previewSizeHeight * 3];
        imageFormat = params.getPreviewFormat();
        mCamera.setParameters(params);
        mCamera.startPreview();

    }

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

    @Override
    public void onPause() {
        this.mCamera.stopPreview();
    }

}

推荐答案

来自 Android 开发者文档:

如果相机已被另一个应用程序使用，则调用 Camera.open() 会引发异常，因此我们将其包装在 try 块中.

Calling Camera.open() throws an exception if the camera is already in use by another application, so we wrap it in a try block.

尝试将代码包装在 try catch 块中，如下所示:

Try wrapping that code in a try catch block like so:

try {
    releaseCameraAndPreview();
    if (camId == 0) {
        mCamera = Camera.open(Camera.CameraInfo.CAMERA_FACING_FRONT);
    }
    else {
        mCamera = Camera.open(Camera.CameraInfo.CAMERA_FACING_BACK);
    }
} catch (Exception e) {
    Log.e(getString(R.string.app_name), "failed to open Camera");
    e.printStackTrace();
}

然后在某处添加这个函数:

Then add this function somewhere:

private void releaseCameraAndPreview() {
    myCameraPreview.setCamera(null);
    if (mCamera != null) {
        mCamera.release();
        mCamera = null;
    }
}

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