无法连接到相机服务

Question

我把我的相机设置为this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);,它工作正常,但如果我改为它PORTRAIT而不是LANDSCAPE然后它崩溃与以下错误...

07-30 12:51:37.655: ERROR/AndroidRuntime(22069): FATAL EXCEPTION: main
07-30 12:51:37.655: ERROR/AndroidRuntime(22069): java.lang.RuntimeException: Fail to connect to camera service
07-30 12:51:37.655: ERROR/AndroidRuntime(22069):     at android.hardware.Camera.native_setup(Native Method)
07-30 12:51:37.655: ERROR/AndroidRuntime(22069):     at android.hardware.Camera.<init>(Camera.java:110)
07-30 12:51:37.655: ERROR/AndroidRuntime(22069):     at android.hardware.Camera.open(Camera.java:90)
07-30 12:51:37.655: ERROR/AndroidRuntime(22069):     at org.digital.com.CamLayer.surfaceCreated(CamLayer.java:3

崩溃的方法是......

public void surfaceCreated(SurfaceHolder holder) {
    synchronized(this) {
        mCamera = Camera.open();

        Camera.Parameters p = mCamera.getParameters(); 
        p.setPreviewSize(800, 480);
        mCamera.setParameters(p);

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

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

它崩溃了 mCamera = Camera.open();

我的清单文件有 <uses-permission android:name="android.permission.CAMERA"></uses-permission>

我如何解决这个问题,以便在Portrait中查看我的应用程序？

Answer 1

平台中存在一些并发问题:http://code.google.com/p/android/issues/detail？id = 6201

解决方法是在释放cam之前清除回调,这是我建议遵循清理代码:

    @Override
public void surfaceDestroyed(SurfaceHolder holder) {
    if (mCam != null) {
        mCam.stopPreview();
        mCam.setPreviewCallback(null);
        mCam.release();
        mCam = null;
    }
}

Answer 2

作为参考,这是我在我的应用程序中使用的SurfaceHolderCallBack内部类,它在纵向模式下在Nexus One 2.2上正常工作 - 希望它有所帮助.

编辑:"哪个工作"="哪个不崩溃".虽然我还没弄清楚如何正确旋转预览图像(请参阅上面的第一条评论).这就是为什么我实际上不得不使用横向和'转换'围绕预览表面的UI内容到横向模式.Afaik预览(正确旋转预览图像)仅适用于横向模式.我试过的旋转和定向参数根本没用.

class SurfaceHolderCallback implements SurfaceHolder.Callback {
    private static final int IMAGE_WIDTH = 512;
    private static final int IMAGE_HEIGHT = 384;
    private static final String ORIENTATION = "orientation";
    private static final String ROTATION = "rotation";
    private static final String PORTRAIT = "portrait";
    private static final String LANDSCAPE = "landscape";

    public void surfaceCreated(SurfaceHolder holder) {
        try {
            // This case can actually happen if the user opens and closes the camera too frequently.
            // The problem is that we cannot really prevent this from happening as the user can easily
            // get into a chain of activites and tries to escape using the back button.
            // The most sensible solution would be to quit the entire EPostcard flow once the picture is sent.
            camera = Camera.open();
        } catch(Exception e) {
            finish();
            return;
        }

        //Surface.setOrientation(Display.DEFAULT_DISPLAY,Surface.ROTATION_90);
        Parameters p = camera.getParameters();
        p.setPictureSize(IMAGE_WIDTH, IMAGE_HEIGHT);

        camera.getParameters().setRotation(90);

        Camera.Size s = p.getSupportedPreviewSizes().get(0);
        p.setPreviewSize( s.width, s.height );

        p.setPictureFormat(PixelFormat.JPEG);
        p.set("flash-mode", "auto");
        camera.setParameters(p);

        try {
            camera.setPreviewDisplay(surfaceHolder);
        } catch (Throwable ignored) {
            Log.e(APP, "set preview error.", ignored);
        }
    }

    public void surfaceChanged(SurfaceHolder holder, int format, int width,
                               int height) {
        if (isPreviewRunning) {
            camera.stopPreview();
        }
        try {
            camera.startPreview();
        } catch(Exception e) {
            Log.d(APP, "Cannot start preview", e);    
        }
        isPreviewRunning = true;
    }

    public void surfaceDestroyed(SurfaceHolder arg0) {
        if(isPreviewRunning && camera != null) {
            if(camera!=null) {
                camera.stopPreview();
                camera.release();  
                camera = null;
            }
            isPreviewRunning = false;
        }
    }
}

Answer 3

你在AndroidManifest.xml中有这个设置吗？

uses-permission android:name="android.permission.CAMERA"